cssi/SciSciGPT-SciSciNet huggingface dataset:
Flow of dilatant (shear‐thickening) fluids

The conduit laminar flow of dilatant (shear-thickening) fluids was investigated. It was found that such flow agreed with the Metzner-Reed (friction factor-modified Reynolds number) correlation previously verified only for pseudoplastic fluids. The agreement was found to hold even for cases where the flow behavior index was 2.0 or greater, which caused the velocity term V in the modified Reynolds number Dn′ V2−n′/gc8n−1K′ to be raised to the zero or a negative power. It was also demonstrated that conduit laminar flow for dilatant (shear-thickening) fluids could be described solely with the Metzner-Reed correlation and rheological data taken with a small-scale laboratory viscometer. Studies of flow through fittings (90-deg. elbows, globe valves, and couplings) showed a definite effect for non-Newtonian fluids contrary to previous reports for pseudoplastics which indicated essentially Newtonian behavior.
Downbeat nystagmus as a result of lamotrigine toxicity.

Abstract Background: Downbeat nystagmus (DBN) has been reported with phenytoin and carbamazepine toxicity. DBN has not been described as a result of lamotrigine toxicity. Methods: Clinical records, neuroimaging and video recordings were obtained in two patients diagnosed with intractable epilepsy who developed oscillopsia and incoordination while being treated with lamotrigine. One patient had a videonystagmographic (VNG) study. Discussion: Lamotrigine's half-life is extended when used with valproic acid; hence, the increased chance of neurotoxicity associated with DBN. In our cases, DBN and truncal ataxia occurred in conjunction with toxic lamotrigine serum levels. Conclusion: Anticonvulsant toxicity should be considered as a cause of DBN. Lamotrigine toxicity may be an unusual cause.
The complex cepstrum of higher order cumulants and nonminimum phase system identification

A computationally efficient identification procedure is proposed for a nonGaussian white-noise-driven linear, time-invariant, nonminimum phase system. The method is based on the idea of computing the complex cepstrum of higher order cumulants of the system output. In particular, the differential cepstrum parameters of the nonminimum phase impulse response are estimated directly from higher-order cumulants by least-squares solution or two-dimensional FFT operations. The method reconstructs the minimum-phase and maximum-phase impulse response components separately. It is flexible enough to be applied on autoregressive (AR), moving average (MA), or ARMA system without a priori knowledge of the type of the system. Benchmark simulation examples demonstrate the effectiveness of the method even with short length data records. >
Endovascular stent-graft placement for nonaneurysmal infrarenal aortic rupture: a case report and review of the literature

Penetrating atheromatous ulceration of the infrarenal aorta is a rare entity. There are few reported cases of this lesion, and most of the published data is in regards to the thoracic aorta. Spontaneous rupture of a nonaneurysmal noninfected atherosclerotic infrarenal aorta is a rare event. We report the eleventh case of this occurrence and present the first reported case of endovascular stent-graft placement in treating this entity. We review the literature regarding ulcerative disease of the aorta and specifically discuss the published data on spontaneous rupture of the nondilated, noninfected infrarenal aorta secondary to penetrating atheromatous ulceration.
σ-Borane Complexes of Iridium: Synthesis and Structural Characterization

Reaction of NaBH4 with (tBuPOCOP)IrHCl affords the previously reported complex (tBuPOCOP)IrH2(BH3) (1) (tBuPOCOP = κ3-C6H3-1,3-[OP(tBu)2]2). The structure of 1 determined from neutron diffraction data contains a B−H σ-bond to iridium with an elongated B−H bond distance of 1.45(5) A. Compound 1 crystallizes in the space group P1 (Z = 2) with a = 8.262 (5) A, b = 12.264 (5) A, c = 13.394 (4) A, and V = 1256.2 (1) A3 (30 K). Complex 1 can also be prepared by reaction of BH3·THF with (tBuPOCOP)IrH2. Reaction of (tBuPOCOP)IrH2 with pinacol borane gave initially complex 2, which is assigned a structure analogous to that of 1 based on spectroscopic measurements. Complex 2 evolves H2 at room temperature leading to the borane complex 3, which is formed cleanly when 2 is subjected to dynamic vacuum. The structure of 3 has been determined by X-ray diffraction and consists of the (tBuPOCOP)Ir core with a σ-bound pinacol borane ligand in an approximately square planar complex. Compound 3 crystallizes in the space gro...
Aftermath of Severe Multiple Deprivation in a Young Child: Clinical Implications:

This clinical case illustrates a child's physical and mental retardation as a result of neglect and abandonment by the family. Specific areas of impairment are illustrated as are various techniques utilized in speech therapy in the rehabilitation of the child.
The THEMIS ESA Plasma Instrument and In-flight Calibration

The THEMIS plasma instrument is designed to measure the ion and electron distribution functions over the energy range from a few eV up to 30 keV for electrons and 25 keV for ions. The instrument consists of a pair of “top hat” electrostatic analyzers with common 180°×6° fields-of-view that sweep out 4π steradians each 3 s spin period. Particles are detected by microchannel plate detectors and binned into six distributions whose energy, angle, and time resolution depend upon instrument mode. On-board moments are calculated, and processing includes corrections for spacecraft potential. This paper focuses on the ground and in-flight calibrations of the 10 sensors on five spacecraft. Cross-calibrations were facilitated by having all the plasma measurements available with the same resolution and format, along with spacecraft potential and magnetic field measurements in the same data set. Lessons learned from this effort should be useful for future multi-satellite missions.
The effect of S− on observing behavior

Abstract Eight pigeons were run on a one-key, discrete-trials observing procedure. Pecks during a trial produced S+ and S−, colored key lights which signalled whether the trial would end with response-independent grain reinforcement or nonreinforcement. S+ and S− were produced on a VI schedule which began operating at the onset of the trial. In the main experimental condition, only a response preceded by at least 6 sec of nonresponding could produce S− on nonreinforced trials; any response which satisfied the VI requirement produced S+ on reinforced trials. This procedure allowed the birds to produce S+ on reinforced trials with or without producing S− on nonreinforced trials. The subjects learned to produce fewer S−s over sessions, indicating that S− had a punishing effect on observing. The results were taken as evidence for the conditioned reinforcement hypothesis of observing and against the uncertainty reduction hypothesis.
Calciotropic hormones and the risk of hip and nonspine fractures in older adults: the Health ABC Study.

The effects of vitamin D and parathyroid hormone (PTH) levels on incident fracture remain uncertain. To test the hypothesis that increasing serum 25-hydroxyvitamin D [25(OH)D] and decreasing PTH levels are associated with decreased risk of hip and any nonspine fracture, we conducted a prospective cohort study among 2614 community-dwelling white and black participants, aged ≥70 years, from the Health, Aging and Body Composition (Health ABC) Study. Serum and plasma samples were drawn at year 2, which formed the baseline for this analysis. Serum 25(OH)D and intact PTH (1-84) were measured using radioimmunoassay with DiaSorin reagents and EDTA plasma with a two-site immunoradiometric assay kit, respectively. Incident fractures (hip and any nonspine) were assessed after year 2, every 6 months, by self-report and validated by radiology reports. The median (interquartile range) follow-up times for hip and any nonspine fractures were 6.4 (6.1–6.5) and 6.4 (5.5–6.5) years, respectively. Cox proportional hazards regression was used to estimate the hazard ratios (HR) with 95% confidence intervals (CI) for fracture. There were 84 hip and 247 nonspine fractures that occurred over the follow-up period. The multivariable adjusted HRs (95% CIs) of hip fracture for participants in the lowest (≤17.78 ng/mL), second (17.79 to 24.36 ng/mL), and third quartiles (24.37 to 31.94 ng/mL) of 25(OH)D were 1.92 (0.97 to 3.83), 0.75 (0.32 to 1.72) and 1.86 (1.00 to 3.45), respectively, compared with participants in the highest 25(OH)D quartile (>31.94 ng/mL) (p trend = 0.217). Additional adjustment for IL-6 (p = 0.107), PTH (p = 0.124), and hip areal bone mineral density (p = 0.137) attenuated HRs of hip fracture in the lowest quartile by 16.3%, 17.4%, and 26.1%, respectively. There was no evidence of an association between 25(OH)D and any nonspine fractures, or between PTH and hip or any nonspine fractures. We found limited evidence to support an association between calciotropic hormones and hip and nonspine fractures in older men and women. © 2012 American Society for Bone and Mineral Research.
Credit-based dynamic reliability management using online wearout detection

As circuit geometries continue to shrink, and supply voltages remain relatively constant, circuit wearout becomes a concern. We propose that the relative reliability of the circuits of a processor be exposed to the operating system, and be managed by a credit-based wearout monitor. This wearout monitor receives dynamic updates of the reliability of circuits through the use of stability detector circuits that are small enough to be widely deployed. We find that through the combined use of the wearout monitor and stability detectors, we can efficiently and accurately manage the reliability of a processor, and re-coup the performance of a processor that would otherwise be lost when processors are over-provisioned to meet an expected lifetime. We simulate a 16 core DSP with a wearout monitor and stability detectors on a mix of four different media algorithms. Using the wearout monitor and stability detectors, we find that by reducing average performance by only 5%, we can increase the lifetime of the processor by 46%.
Creep behavior and deformation mechanisms in a nanocluster strengthened ferritic steel

Abstract Mechanically alloyed, nanostructured ferritic steels represent a class of alloys that can display high resistance to radiation and creep deformation, which are derived from the presence of nanoclusters, precipitates and solute segregation to the grain boundaries. The creep responses for a 14YWT nanostructured ferritic steel were measured over a range of temperatures and stress levels. The stress exponent was observed to vary non-linearly with applied stress; stress exponents were found to decrease with decreasing stress approaching unity at low stress. Transmission electron microscopy studies clearly demonstrated that creep deformation proceeds by a dislocation glide within nanoscale grains and that glide dislocations are attracted to and pinned by nanoclusters. In light of these observations, a new model of the creep response, inspired by the Kocks–Argon–Ashby model, is developed to explain the low creep rates and small stress exponents that are exhibited by these alloys.
RNAi screening of the kinome identifies modulators of cisplatin response in ovarian cancer cells

Abstract Objective Ovarian cancer retains a poor prognosis among the female gynaecological malignancies. It constitutes about 3% of all malignancies in women and accounts for 5% of all female cancer related deaths. A standard treatment is cytoreductive surgery followed by adjuvant chemotherapy, and re-treatment with platinum based chemotherapy at the time of relapse. In order to improve cisplatin response in ovarian cancer cells, we utilized a high-throughput RNAi screening to identify kinase modulators. Methods A high-throughput RNAi screen was performed using a siRNA library targeting 572 kinases to identify potentiators of cisplatin response in the ovarian cancer cell line SKOV3. Results RNAi screening identified at least 55 siRNAs that potentiated the growth inhibitory effects of cisplatin in SKOV3 cells. Inhibition of ATR and CHK1 resulted in the greatest modulation of cisplatin response. Drug dose response of cisplatin in the presence of siRNA validated the effects of these target genes. To show that the siRNA data could be successfully translated into potential therapeutic strategies, CHK1 was further targeted with small molecule inhibitor PD 407824 in combination with cisplatin. Results showed that treatment of SKOV3 and OVCAR3 cells with CHK1 inhibitor PD 407824 led to sensitization of ovarian cancer cells to cisplatin. Conclusions Our data provides kinase targets that could be exploited to design better therapeutics for ovarian cancer patients. We also demonstrate the effectiveness of high-throughput RNAi screening as a tool for identifying sensitizing targets to known and established chemotherapeutic agents.
Exposure to female rats produces differences in c-fos induction between sexually-naïve and experienced male rats.

Sexual incentive-induced Fos-like immunoreactivity (Fos-Li) within six neural regions implicated in male sexual behavior was investigated in both sexually-naive and experienced male rats. Sexual experience was limited to one copulation culminating in ejaculation 24 h prior to testing. On test-day, subjects were placed within a cylindrical arena for 15 min on the opposite side of a perforated, Plexiglas partition from one of three targets: an uninhabited area, a non-estrous female, or an estrous female. Then 1 h later, each subject was sacrificed and its brain prepared for subsequent immunocytochemical staining. Analyses revealed a main effect of target stimulus on c-fos expression within the nucleus accumbens shell and core of male subjects. In addition, sexually-experienced subjects demonstrated significantly more Fos-Li within the nucleus accumbens shell in response to an estrous female versus a non-estrous female. There was also greater estrous cue-induced Fos-Li in the nucleus accumbens shell of experienced subjects when compared to naive subjects. These data support previous suggestions implicating the nucleus accumbens in the generation of male sexual motivation. In addition, copulatory experience, even when limited to one ejaculation, seems to mediate long-term changes in the response properties of nucleus accumbens neurons that may reflect the value enhancement of primary female incentives.
An average response technique for recording potentials relative to a distant point without EKG interference.

Abstract A technique is described which can be used in evoked response studies to evaluate the electrical activity of an electrode relative to a distant point without electrocardiographic signal interference. The recording sweep and the onset of the stimulus are triggered from the electrocardiogram after a variable delay so that the average is obtained in a relatively flat portion of the electrocardiographique
Ocular Findings in Cytogenetic Syndromes

Abstract Several cytogenetic syndromes are reviewed, and the salient ocular and facial abnormalities that might lead to a diagnosis are pointed out. Examples are given of mongoloid slant to the palpebral fissures, not only in Down's syndrome but also in monosomy 9p, where, in addition, the triangular skull is almost diagnostic. Antimongoloid slant is found in trisomy 9p, where the eyes also have enophthalmos of monosomy 9p. Hypertelorism is another common finding in these syndromes; in monosomy 5p it is almost always present, although it occurs in other conditions as well, including trisomy 12p. The ring 22 syndrome has a distinguishing finding called “doe's eyes” because of the shape of the palpebral fissures. Trisomy 13 has numerous ocular findings as well as skull and facial involvements.
The Local Isometric Embedding Problem for 3-Dimensional Riemannian Manifolds with Cleanly Vanishing Curvature

We prove the following result: let (M, g) be a 3-dimensional C ∞ Riemannian manifold for which there exists a p ∈ M and a v ∈ T p M such that Then there exists a C ∞ isometric embedding from a neighborhood of p into ℝ6.
Enhancement of the cochlear nerve compound action potential: sharply defined frequency-intensity domains bordering the tuning curve.

Abstract Forward masking can either decrease or increase the response to a subsequent stimulus. In the gerbil, frequency-intensity domains of the maskers that decrease the amplitude of the compound action potential (CAP) can be plotted as the sharply defined CAP tuning curve (TC). Regions were also found over which masking increases (enhances) the amplitude of the CAP. Center-frequency (CF) enhancement domains were found in approximately 2 3 of the animals tested, in response to maskers having frequencies very near that of the probe stimulus, at levels ranging from below the CAP detection threshold to just below the tip threshold of the TC. Approximately 2 3 of the animals showing CF enhancement also displayed low-frequency (LF) enhancement, in response to a domain which borders the low-frequency tail of the TC.
Potential world garbage and waste carbon sequestration

Abstract To offset the carbon dioxide released by fossil fuels, a proposed sequestration strategy relies on burying garbage and waste in landfills. This paper roughly estimates the current annual world supply of carbonaceous waste to be 35.5 billion metric tons and to contain about 18 billion metric tons of carbon. If landfills received all of this waste, sequestration of more than 5.6 billion metric tons of carbon seems theoretically possible—an amount well in excess of the 3.3 billion metric tons which the atmosphere is currently gaining.
Nature and origin of comets

IN so many fields of astrophysics the textbooks and the ordinary review articles have a tendency to present only the ‘generally accepted’ point of view, often not mentioning alternative theories, and even sweeping under the rug those observational facts which are adverse to the dominant view. This also applies to the theory of comets. As the arrival of Comet Kohoutek, and also the space missions to comets which are now being planned, is focusing the interest on comets, we may have unique opportunities in the near future to clarify which views are correct. This calls for a survey of the controversial points. A partial list of these, with which we will be concerning ourselves here, is the following: (1) What is the physical nature of the cometary nucleus? (a) Does it invariably consist of a single monolith ? or (b) could it, in some instances at least, constitute a bunch of particles having no physical coherence ? (2) What is the genetic relationship between comets and the meteor streams with which they are associated ? (a) Do the stream meteoroids invariably derive from the associated comets ? or (b) is the reverse process also possible ? (3) Is there a net dissipation or accretion during the lifetime of a comet ? (4) What is the origin of short-period comets ? (5) What is the origin of long-period comets ? Several other questions with regard to the chemical composition of the nucleus, the mechanisms for the production of the observed radicals and ions, and the nature of the comet solarwind interaction merit discussion but are outside the scope of this letter.
Relationship of War-Zone Coping Strategies to Long-Term General Life Adjustment Among Vietnam Veterans: Combat Exposure as a Moderator Variable

In this study, we examined long-term general life adjustment among members of one trauma-exposed population, Vietnam veterans, using data from a nationally representative sample. Our particular concern was the relationship between coping strategies used in the war zone and the outcomes of achievement, life satisfaction, and lifetime adaptation (the latter defined in terms of the absence of psychosocial problems in core life domains) as a function of level of combat exposure. Hierarchical multiple regression analyses supported a hypothesized quadratic interaction between problem-focused coping and the outcomes of achievement and lifetime adaptation, with this form of coping most strongly related to adjustment (positively) at moderate levels of combat exposure. One aspect of emotion-focused coping, the use of wishful thinking, likewise interacted in a quadratic manner for the dependent variable of achievement, exhibiting its strongest association with adjustment (negatively) at moderate levels of combat exposure. The importance of interactions between coping and stressors, especially quadratic interactions, is emphasized.
A scalable messaging system for accelerating discovery from large scale scientific simulations

Emerging scientific and engineering simulations running at scale on leadership-class High End Computing (HEC) environments are producing large volumes of data, which has to be transported and analyzed before any insights can result from these simulations. The complexity and cost (in terms of time and energy) associated with managing and analyzing this data have become significant challenges, and are limiting the impact of these simulations. Recently, data-staging approaches along with in-situ and in-transit analytics have been proposed to address these challenges by offloading I/O and/or moving data processing closer to the data. However, scientists continue to be overwhelmed by the large data volumes and data rates. In this paper we address this latter challenge. Specifically, we propose a highly scalable and low-overhead associative messaging framework that runs on the data staging resources within the HEC platform, and builds on the staging-based online in-situ/in-transit analytics to provide publish/subscribe/notification-type messaging patterns to the scientist. Rather than having to ingest and inspect the data volumes, this messaging system allows scientists to (1) dynamically subscribe to data events of interest, e.g., simple data values or a complex function or simple reduction (max()/min()/avg()) of the data values in a certain region of the application domain is greater/less than a threshold value, or certain spatial/temporal data features or data patterns are detected; (2) define customized in-situ/in-transit actions that are triggered based on the events, such as data visualization or transformation; and (3) get notified when these events occur. The key contribution of this paper is a design and implementation that can support such a messaging abstraction at scale on high-end computing (HEC) systems with minimal overheads. We have implemented and deployed the messaging system on the Jaguar Cray XK6 machines at Oak Ridge National Laboratory and the Lonestar system at the Texas Advanced Computing Center (TACC), and we present the experimental performance evaluation using these HEC platforms in the paper.
Mass Resolution Enhancement in Local-Electrode Atom Probes : A Preliminary Study Using Field Emitter Arrays

The use of post-evaporation acceleration as a means to enhance mass resolution in local-electrode atom probes (LEAP) is experimentally investigated in this study. Gated silicon field emitter arrays which have an extraction electrode-tip structure similar to a LEAP are used to evaporate ions at low voltages which are then accelerated to higher voltages. The study confirms the expected improvement in mass resolution. The mass resolution achieved using this gated field emitter array is however quite poor owing to capacitive coupling between the extraction electrode and the tip which leads to a broadened evaporation pulse. An improved model to relate time-of-flight to ion mass-to-charge ratio is found to be necessary in this atom probe configuration. These findings suggest important design considerations for extraction electrodes for a LEAP.
Cost-efficient soft error protection for embedded microprocessors

Device scaling trends dramatically increase the susceptibility of microprocessors to soft errors. Further, mounting demand for embedded microprocessors in a wide array of safety critical applications, ranging from automobiles to pacemakers, compounds the importance of addressing the soft error problem. Historically, soft error tolerance techniques have been targeted mainly at high-end server markets, leading to solutions such as coarse-grained modular redundancy and redundant multithreading. However, these techniques tend to be prohibitively expensive to implement in the embedded design space. To address this problem, we first present a thorough analysis of the effects of soft errors on a production-grade, fully synthesized implementation of an ARM926EJ-S embedded microprocessor. We then leverage this analysis in the design of two orthogonal low-costs of terror protection techniques that can be tuned to achieve variable levels of fault coverage as a function of area and power constraints. The first technique uses a small cache of live register values in order to provide nearly twice the fault coverage of a register file protected using traditional error correcting codes at little or no additional area cost. The second technique is a statistical method used to significantly reduce the overhead of deploying time-delayed shadow latches for low-latency fault detection.
Turbulent Flow and Heat Transfer in Variable Geometry U-Bend Blade Cooling Passage

In modern gas turbine blades it has been a common practice to use cooling passages in gas turbine blades. In cooling processes blades have excessive thermal stresses, causing creep, oxidizing and also melting in some cases. Therefore fully understanding of the flow characteristics in the U-bend is important in designing cooling passages. The interactions between secondary flows and separation lead to very complex flow patterns. To accurately simulate these flows and heat transfer, and to improve the cooling performance, both refined turbulence models and higher-order numerical schemes are indispensable tools for turbine designers. It is the conventional belief and practice that the usage of a proper turbulence model and a reliable numerical method achieves accurate computations. The three-dimensional turbulent flows and heat transfer in a square U-bend duct are numerically studied by using a Large Eddy Simulation (LES) model. Simulation using k-ω, k-e and RSM models has been previously reported, and used here to compare with the LES simulation. The finite volume method incorporated with higher-order bounded interpolation scheme has been employed in the present study. The objective of this study is to validate the simulation of LES model with the experimental results. Three different Reynolds numbers, 36000, 60000 and 100000, were used. This study concludes that the RSM is a better model, for Re = 36,000 and 60,000.Copyright © 2009 by ASME
Object-Based Regions of Interest for Image Compression

A fully automated architecture for object-based region of interest (ROI) detection is proposed. ROI's are defined as regions containing user defined objects of interest, and an efficient algorithm is developed for the detection of such regions. The algorithm is based on the principle of discriminant saliency, which defines as salient the image regions of strongest response to a set of features that optimally discriminate the object class of interest from all the others. It consists of two stages, saliency detection and saliency validation. The first detects salient points, the second verifies the consistency of their geometric configuration with that of training examples. Both the saliency detector and the configuration model can be learned from cluttered images downloaded from the web. Learning and ROI detection are optimal in the minimum probability of error (MPE) sense, and computationally efficient. This enables interactive user training of ROI-based image coders, with minimal amounts of manual supervision. Experimental results are presented for images of complex scenes, containing both objects and background clutter, and demonstrate good object-based ROI image compression performance.
Environmental hazards and school segregation in Hillsborough County, Florida, 1987-1999

This article draws upon the political economy and urban ecology of race perspectives to examine trends in school segregation for schools located various distances from environmental hazards. We study trends in segregation among eighty-four public grade schools between the years of 1987 and 1999 in the Hillsborough County (Florida) School District. After controlling for the percentage of students eligible for free lunch, we find that grade schools nearer to environmental hazards became disproportionately black and Hispanic while grade schools situated farther from hazards became disproportionately white. These results are consistent with a political economy of race perspective. We argue that the observed relationship between public school racial and ethnic composition and environmental hazards is likely the result of long-term historical processes that shaped geographic patterns of racial segregation.
Compartmentalization of the cat lateral gastrocnemius motor nucleus

The spatial and size distributions of motoneurons which supply the cat lateral gastrocnemius (LG) neuromuscular compartments were examined to determine their anatomical organization. Individual primary muscle nerve branches (PMNB) to LG were isolated by microdissection, cut, and soaked in horseradish peroxidase (HRP). As a control in each case, the entire contralateral lateral gastrocnemius-soleus (LG-S) nerve was similarly cut and soaked. Retrogradely labeled motoneurons were identified, their positions plotted, and their sizes measured on both sides of the cord. Results show that extensive overlap exists in the spatial distribution of motoneurons innervating different PMNBs. Labeled cells supplying each PMNB also vary considerably in their sizes. However, both a highly significant topography-like organization and a preferential size distribution are found between different groups of motoneurons. Neurons which supply proximal compartments occupy more rostral portions of the LG motor nucleus and are among the largest in the pool. Very few small motoneurons innervate proximal compartments. Neurons supplying more distal compartments are distributed in more caudal parts of the pool and contain both large and small cells in relatively equal numbers. If the large cells are alpha and the small cells gamma motoneurons, then proximal compartments are relatively poor in gamma innervation and presumably muscle spindles, and distal compartments are rich in fusimotor innervation.
Analysis of C3 deposition and degradation on Neisseria meningitidis and Neisseria gonorrhoeae.

Abstract The deposition and degradation of human complement component C3 on the cell surfaces of Neisseria meningitidis and Neisseria gonorrhoeae were studied. Bacteria were incubated in human serum, and ester-linked C3 fragments were analyzed by hydroxylamine release and immunoblot detection. Similar patterns of C3 degradation were found for both serum-resistant and serum-sensitive meningococcal strains of serogroups A, B, C, Y, and W135, as well as for serum-sensitive gonococcal strains and their sialylated serum-resistant variants. The predominant fragments in all cases were the 40-kDa alpha' 2 chain of iC3b and the 75-kDa beta chain common to both C3b and iC3b. The 67-kDa alpha' 1 chain of iC3b was also detected. The 105-kDa alpha' chain of intact C3b represented a minor proportion of deposited C3. Capsule-specific immunoglobulin G or immunoglobulin A1 did not alter the observed degradation patterns, nor did incubation of meningococci in properdin-deficient serum. The degradation of C3 in C5-, C6-, or C8-deficient serum was the same as that in normal serum, although the deposition of C3 was severely limited, based as indicated by the intensity of the fragments. With the use of an enzyme-linked immunosorbent assay that measured total iC3b and C3, I found that both iC3b deposition and C3 deposition varied among meningococcal and gonococcal strains and that the amounts of iC3b and C3 were independent of the relative quantities of cell surface sialic acid and of serum sensitivity for meningococci but not for gonococci. I conclude that complement activation on neisserial cell surface results in the formation of an identical repertoire of predominantly iC3b fragments of ester-linked C3b molecules regardless of the presence of sialic acid in either the capsule or the lipooligosaccharide or of the sensitivity of the organism to complement-mediated lysis but that the quantities of both ester- and amide-linked iC3b molecules deposited exhibit strain variability.
The spatial self: Location-based identity performance on social media

As a growing number of social media platforms now include location information from their users, researchers are confronted with new online representations of individuals, social networks, and the places they inhabit. To better understand these representations and their implications, we introduce the concept of the “spatial self”: a theoretical framework encapsulating the process of online self-presentation based on the display of offline physical activities. Building on previous studies in social science, humanities, and computer and information science, we analyze the ways offline experiences are harnessed and performed online. We first provide an encompassing interdisciplinary survey of research that investigates the relationships between location, information technology, and identity performance. Then, we identify and characterize the spatial self as well as examine its occurrences through three case studies of popular social media sites: Instagram, Facebook, and Foursquare. Finally, we offer possible...
Dispersal Promotes Compensatory Dynamics and Stability in Forced Metacommunities

Understanding the factors that govern the stability of populations and communities has gained increasing importance as habitat fragmentation and environmental perturbations continue to escalate due to human activities. Dispersal is commonly viewed as essential to the maintenance of diversity in spatially subdivided com- munities, but few experiments have explored how dispersal interacts with the spatiotemporal components of environmental perturbations to determine community-level stability. We examined these processes using an experimental planktonic system composed of three com- peting species of zooplankton. We subjected zooplankton metacom- munities to varying levels of dispersal and pH perturbations that varied in their degree of spatial synchrony. We show that dispersal can reverse the destabilizing effects of environmental forcing when perturbations are spatially asynchronous. Asynchrony in pH pertur- bations generated spatially and temporally varying species refugia that promoted source-sink dynamics and allowed prolonged persis- tence of zooplankton species that were otherwise extirpated in syn- chronously varying metacommunities. This, in turn, increased local species diversity, promoted compensatory population dynamics, and enhanced local community-level stability. Our results indicate that patterns of spatial covariation in environmental variability are critical to predicting the effects of dispersal on the dynamics and persistence of communities.
Gettering of threading dislocations and oxide precipitates in SIMOX material

Summary form only given. Several methods for gettering defects such as threading dislocations and oxide precipitates in SIMOX material are discussed. The multiple implant/anneal cycle technique is very effective in reducing dislocation density. A second technique involves dislocation gettering by hetero-epitaxy. Finally, the elimination of oxide precipitates by hydrogen ambient anneal is discussed. >
On the interaction of internal gravity waves with a magnetic field ― I. Artificial wave forcing

We present results from numerical simulations of the interaction of internal gravity waves (IGW) with a magnetic field. In accordance with the dispersion relation governing IGW in the presence of magnetism and rotation, when the IGW frequency is approximately that of the Alfven frequency, strong reflection of the wave occurs. Such strong reflection markedly changes the angular momentum transport properties of the waves. In these simple models a strong, time-independent shear layer develops, in contrast to the oscillating shear layer that develops in the purely hydrodynamic case.
Erythropoietic Stimulating Activity of Urine from Anemic Human Subjects.

SummaryOf 17 unconcentrated urine samples taken from 7 anemic humans, approximately 25% displayed erythropoietic stimulating properties. Blood volume and bone marrow studies confirmed the erythropoietic nature of the responses obtained. Urine from 4 children with normal hemoglobin levels showed no ability to stimulate erythropoiesis. When compared to anemic human plasma, anemic human urine is a more dilute and less constant source of erythropoietically active material.
Trial-selective effects of U50,488H, a κ-opioid receptor agonist, on consummatory successive negative contrast

A series of experiments studied the effects of the kappa-opioid receptor agonist U50,488H on consummatory successive negative contrast (cSNC) in rats. In cSNC, previous experience with a 32% sucrose solution leads to greater rejection of 4% sucrose than exclusive experience with 4% sucrose. Experiments 1 and 2 revealed that U50,488H failed to influence cSNC when administered before the first downshifted trial, but either attenuated (1mg/kg) or enhanced (3 and 10mg/kg) cSNC when administered before the second downshift trial. Experiment 3 showed that U50,488H administered immediately after the first downshift trial had no effect on cSNC at the 1mg/kg dose, but tended to increase cSNC at the 3mg/kg dose. However, Experiment 4 suggested that the apparent enhancement of cSNC after 3mg/kg U50 administered posttrial 11 may have reflected the development of a conditioned taste aversion. The trial-selective attenuating effect of the low dose may reflect an anxiolytic-like property of U50,488H.
The Broad-Spectrum Antiviral Compound ST-669 Restricts Chlamydial Inclusion Development and Bacterial Growth and Localizes to Host Cell Lipid Droplets within Treated Cells

ABSTRACT Novel broad-spectrum antimicrobials are a critical component of a strategy for combating antibiotic-resistant pathogens. In this study, we explored the activity of the broad-spectrum antiviral compound ST-669 for activity against different intracellular bacteria and began a characterization of its mechanism of antimicrobial action. ST-669 inhibits the growth of three different species of chlamydia and the intracellular bacterium Coxiella burnetii in Vero and HeLa cells but not in McCoy (murine) cells. The antichlamydial and anti-C. burnetii activity spectrum was consistent with those observed for tested viruses, suggesting a common mechanism of action. Cycloheximide treatment in the presence of ST-669 abrogated the inhibitory effect, demonstrating that eukaryotic protein synthesis is required for tested activity. Immunofluorescence microscopy demonstrated that different chlamydiae grow atypically in the presence of ST-669, in a manner that suggests the compound affects inclusion formation and organization. Microscopic analysis of cells treated with a fluorescent derivative of ST-669 demonstrated that the compound localized to host cell lipid droplets but not to other organelles or the host cytosol. These results demonstrate that ST-669 affects intracellular growth in a host-cell-dependent manner and interrupts proper development of chlamydial inclusions, possibly through a lipid droplet-dependent process.
Buffer control techniques for compressed-domain video editing

This paper describes algorithms to edit compressed video sequences, e.g., MPEG, directly in the compressed domain. We propose innovative methods to solve the buffer overflow/underflow issues resulted from video editing. Since full decoding of input sequences and re-encoding of the new video sequence are not required, image quality degradation and intensive computations are avoided. High quality, real-time video editing can be achieved.
Effects of Magnesium Sulfate Infusion Upon Plasma Prostaglandins in Preeclampsia and Preterm Labor

Objective: Recent investigation has shown that magnesium stimulates the release of prostacyclin from confluent endothelial cell cultures. The goal of this study was to determine the effect of magnesium sulfate infusion on the peripheral concentrations of prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and 6-keto-prostaglandin F1α (6-keto-PGF1α the stable metabolite of prostacyclin) in women with either preeclampsia or preterm labor. We hypothesized that plasma prostacyclin concentrations would increase during magnesium sulfate infusion in women with preeclampsia to a greater extent than in women with preterm labor.Methods: Twenty-one women with preeclampsia and 14 women in preterm labor were enrolled in a prospective study following transfer to a tertiary center. Blood samples were obtained prior to initiating the magnesium sulfate infusion, immediately after a 4-g load and 2 h later during a maintenance infusion of 2 g/h.Main Outcome Measures: 6-keto-PGF1α PGE2 and PGF2α concentrations were measured a...
Reducing Cellular Energy Requirements as Protection Against CNS Ischemia

Three considerations, taken together, make research on the treatment of brain ischemia seem eminently worthwhile: (a) during ischemia, tissue destined for infarction is usually receiving an appreciable fraction of the minimum blood flow required for cell survival [7, 10, 13]; (b) the time to irreversibility is considerably longer than previously thought and may be measured in terms of half hours or hours [6, 8]; (c) restoration of circulation usually can be anticipated within hours or days as a result of clot lysis or collateral enlargement. Aggressive measures to forestall cell death may therefore be justified.
On Defining Subjective and Objective Measurements

The adjectives “objective” and “subjective” frequently precede the noun “measurement,” but all too often the terms are used without precision. Kerlinger has described objective measurements in terms of reliability. He states, “An objective procedure is one in which agreement among observers is at maximum. In variance terms, observer variance is at a minimum.”1 Therefore, an objective measurement is one in which there is reasonable intertester (interobserver) reliability. Kerlinger even describes a strategy that can be used to increase the likelihood of obtaining objective measurements: Objective methods of observations are those in which anyone following the prescribed rules will assign the same numerals to objects and sets of objects as anyone else.1 All too often the term objective is applied to a measurement that someone thinks highly of, whereas subjective is used in a derogatory fashion to demean a measurement.…
The Polymerization Pocket “a” within the Carboxyl-terminal Region of the γ Chain of Human Fibrinogen Is Adjacent to but Independent from the Calcium-binding Site

The carboxyl-terminal region of the gamma chain of fibrinogen is involved in calcium binding, fibrin polymerization, factor XIIIa-mediated cross-linking, and binding to the platelet fibrin(ogen) receptor. Protein fragments encoding amino acids Val143 to Val411 (rFbggammaC30) or Val143 to Leu427 (gamma'C30) from the carboxyl end of the gamma or gamma' chains, respectively, of human fibrinogen were expressed in yeast (Pichia pastoris) and characterized as to their cross-linking by factor XIIIa, polymerization pocket, and calcium-binding site. rFbggammaC30 and gamma'C30 were both readily cross-linked by factor XIIIa, but only rFbggammaC30 was capable of inhibiting thrombin-induced platelet aggregation. Two mutants, gammaC30-Q329R and gammaC30-D364A, which were based on the three-dimensional structure of the polymerization pocket within rFbggammaC30 and on information derived from naturally occurring mutant fibrinogens, were also expressed and characterized. rFbggammaC30 inhibited (desAA)fibrin polymerization in a dose-dependent manner, while the two mutant forms did not. Similarly, rFbggammaC30 and gamma'C30 were protected from plasmin degradation by the presence of Ca2+ or the peptide Gly-Pro-Arg-Pro, indicating that a functional Ca2+-binding site and polymerization pocket are contained within each of these fragments. The mutant fragments, however, were protected from plasmin only by metal ions, while no protective effect was conferred by GPRP or by any other peptide tested. These results indicate that the polymerization pocket "a", which binds the peptide GPRP, functions independently from the nearby calcium-binding site and that amino acids Gln329 and Asp364 play a crucial role in fibrin polymerization.
Quantitative investigation of palatal bone depth and cortical bone thickness for mini-implant placement in adults

Introduction Cortical bone thickness and overall bone depth are important factors to consider when placing an orthodontic mini-implant. The purpose of this study was to investigate both variables in the palate quantitatively to aid clinicians in planning successful mini-implant placements. Methods Thirty dry skulls were imaged with cone-beam computed tomography technology. Coronal slices were generated on which overall bone depth and cortical bone thickness were measured at 4 levels and 34 palatal placement sites. One-way analysis of variance (ANOVA) was used for data analysis. Results Overall bone depth decreased with increasing distance from the midsagittal plane and from the anterior to the posterior palatal regions. Cortical bone thickness decreased from anterior to posterior, but no differences were detectable within measurement levels. Conclusions Bone depth and cortical bone thickness of the palate were most favorable for temporary anchorage device placement at the level of the first and second premolars. This information could aid clinicians in choosing suitable palatal placement sites for orthodontic mini-implants.
An Ethnographic, Controlled Study of the Use of a Computer-based Histology Atlas during a Laboratory Course

Objective: To evaluate the use and effect of a computer-based histology atlas during required laboratory sessions in a medical school histology course. Design: Ethnographic observation of students' interactions in a factorial, controlled setting. Measurements: Ethnographer's observations; student and instructor self-report survey after each laboratory session with items rated from 1 (least) to 7 (best); microscope practicum scores at the end of the course. Results: Between groups assigned the atlas and those not, the ethnographer found qualitative differences in the semantic categories used by students in communicating with each other and with the faculty. Differences were also found in the quality of the interactions and in the learning styles used with and without the computer present in the laboratory. The most interactive learning style was achieved when a pair of students shared a computer and a microscope. Practicum grades did not change with respect to historical controls. Students assigned the atlas, compared with those not assigned, reported higher overall satisfaction (a difference in score of 0.1, P = 0.003) and perceived their fellow students to be more helpful (a difference of 0.11, P = 0.035). They rated the usefulness of the microscope lower (a difference of 0.23, P < 0.001). Conclusion: A computer-based histology atlas induces qualitative changes in the histology laboratory environment. Most students and faculty reacted positively. The authors did not measure the impact on learning, but they found that there are aspects of using the atlas that instructors must manipulate to make learning optimal. Ethnographic techniques can be helpful in delineating the context and defining what the interventions might be.