cssi/SciSciGPT-SciSciNet huggingface dataset:
Variation in methane production pathways associated with permafrost decomposition in collapse scar bogs of Alberta, Canada

[1] Stable isotope analysis was used to determine the distribution of methanogenic pathways at permafrost collapse scar bogs to test the hypothesis that microbial respiration and methane production are stimulated by the input of organic matter associated with permafrost degradation and collapse. An alternative hypothesis is that recently assimilated carbon produced by the fen-like vegetation (Carex, Eriophorum) growing in open water moats formed by the collapsing edge of these features stimulates microbial respiration. We found that CO2 reduction was the dominant pathway for methanogenesis within the Sphagnum areas that dominate the surface cover of these features, but relatively more acetate fermentation occurred near collapse scar moats. Methane emission and net CO2 uptake were correlated. Both were elevated in collapse scar moats and then decreased along a transect from the moats toward the center Sphagnum-dominated areas. There also appeared to be a shift toward relatively more acetate fermentation in deeper samples associated with increasing cation (calcium and magnesium) concentrations. Our results indicate that organic inputs from permafrost degradation alone do not appear to stimulate acetate fermentation. Permafrost decomposition provides conditions along the collapsing edge that are conducive to colonization by fen-like vegetation that stimulates acetate fermentation and increases methane production and emission rates.
CRYSTALLIZATION BEHAVIOR OF A BULK AMORPHOUS Zr64Cu18Ni10Al8 ALLOY

The bulk amorphous Zr64Cu18Ni10Al8 alloy with a diameter of 5 mm was successfully obtained by an injection-casting method. The equilibrium crystallization temperature and the associated activation energy of the amorphous alloy were determined using differential scanning calorimetry and Kissinger's peak shift method. The mechanical properties were determined by microhardness. The results show that the bulk amorphous Zr64Cu18Ni10Al8 alloy, the glass transition temperature is 380°C, the crystallization temperature is 482°C, the crystallization temperature at infinitesimal heating rate is extrapolated to be 442°C, the associated activation energy is 103 kJ/mol, and the Vickers hardness is 540 for the Zr64Cu18Ni10Al8 bulk amorphous alloy. The energy barrier of crystallization for the amorphous Zr-based alloy is much less than the amorphous Fe- and Ti- based alloy. The hardness value of is 1.6 times larger than the cast titanium and steel. Therefore hopefully we can develop these bulk amorphous alloy into the application on sporting goods, micro-mechanical devices and aerospace industries.
AN INTEGRATED VIEW OF AIR TRAFFIC MANAGEMENT PROBLEMS

The problems of ATM (Air Traffic Management) are described in a systematic way in order to provide a coherent basis for future research. The capacitated elements of the ATC system are identified as the Runway Systems at major airports, and Airspace Sectors within the airways network. Control over congestion can be exercised through ATM “directives” identified as Speed Reduction, Aircraft Reroute, Flight Initiation Delay, and Restructure Airspace Geometry. Sub-processes in ATM are identified as Arrival Flow Management, Terminal Area Departure Flow Management, Airport Ground Flow Management, and Sector Flow Management. The primary role of uncertainty in predicting traffic flow rates and air traffic capacities is explained in the operation of a real-time, dynamic ATM process.
Paracolloid of the Skin

The concept of paracolloid was raised by Dupre et al. in 1979 to describe a rare lesion, in which large amounts of homogeneous, pale pink, non-amyloid material in sun-exposed skin. The deposits consisted of haphazardly arranged microfilaments of 3–4 nm in diameter. Here we report another case. A 54-year-old white male presented with a 2 × 2 cm boggy, erythematous plaque involving the bridge and tip of the nose for two years. The lesion enlarged slowly and intermittently drained pinkish fluid. A shave biopsy revealed extensive homogeneous, pale pink material with fissure and clefts in the dermis. The deposits wrapped up hair follicles and sebaceous glands, and superficially mixed with scattered solar elastic fibers and globules. There were scattered fibroblasts, focal mild perivascular and perifollicular lymphocyte and plasma cells. Adjacent skin showed prominent solar elastosis. A thin grenz zone was present abutting an atrophic epidermis with actinic keratosis. The deposits showed faint Congo red stain with focal weak apple-green birefringence, faint PAS stain, and negative Verhoeff-van Gieson stain. Masson’s trichrome stain and immunohistochemical stain for collagen IV were negative.
Spiritual Pain in Meals on Wheels' Clients

Background: Meals on Wheels’ clients are at risk for spiritual pain due to advanced age, social isolation, and failing health. They are also prone to stress, depression, and loneliness, placing them at risk for adverse biological disruptions and health outcomes. The purpose of the study was to examine associations of spiritual pain with psychosocial factors (stress, depression, loneliness, religious coping) and salivary biomarkers of stress and inflammation (cortisol, IL-1β) in Meals on Wheels’ clients. Methods: Data were collected cross-sectionally from 88 elderly (mean age 75.4). Spiritual pain, stress, depression, loneliness, and religious coping were measured with standardized instruments, and salivary biomarkers were assessed with enzyme immunoassays. Results: Spiritual pain was significantly and positively correlated with stress (r = 0.35, p ≤ 0.001), depression (r = 0.27, p = 0.01), and negative religious coping (r = 0.27, p = 0.01). Correlations with loneliness, positive religious coping, and salivary biomarkers were non-significant. Conclusion: Spiritual pain is an important concept in this population. Research should be expanded to understand the significance of spiritual pain in conjunction with psychosocial and biological variables and its potential impact on physical, mental, and cognitive health outcomes in the elderly.
Benefits & Costs of Kyoto

The 1998 Kyoto protocol signalled a new earnestness of international intent toward addressing the perceived risk of climate change. Kyoto demands that developed nations turn their economies so as to hit differentiated, sub-1990 level carbon emission targets within the next decade or so. But when thinking of the Kyoto protocol imagine trying to turn a battleship on a dime with a third of the crew on-board. Improbable, but doable...but for what benefit...and at what cost? The magnitude depends on what you choose to believe about the answer to these questions: Are we on the cusp of a catastrophe? Will developing countries ever participate? What will we do with any revenues that are raised in a trading system? Should nations be forced to reduce some fixed percentage of emissions at home? Can carbon sinks reduce costs? Will people adopt new energy-efficient technologies without a price hike in energy? The answers to these questions from economic analysis say that the catastrophes have to be exceedingly likely for Kyoto to make sense.
Urban african american youth exposed to community violence: a school-based anxiety preventive intervention efficacy study

This study evaluated the efficacy of a school-based anxiety prevention program among urban children exposed to community violence. Students who attended Title 1 public elementary schools were screened. Ninety-eight 3rd-5th-grade students (ages 8-12; 48% female; 92% African American) were randomized into preventive intervention versus wait list comparison groups. Students attended 13 biweekly one-hour group sessions of a modified version of FRIENDS, a cognitive-behavioral anxiety intervention program. Results indicated that both intervention and control groups manifested significant reductions in anxiety symptomatology and total exposure to community violence, along with improved standardized reading achievement scores. Additional gains observed only in the intervention group were increased standardized mathematics achievement scores, decreased life stressors, and reduced victimization by community violence. The intervention was equally efficacious for both genders and for children exposed to higher, compared to lower, levels of community violence. Implications for comprehensive, culturally and contextually relevant prevention programs and research are discussed.
High T waves in the earliest stage of myocardial infarction.

Abstract Twenty-seven instances of myocardial infarction were studied, in which the first electrocardiogram was taken as early as one and one-quarter hours, and not later than twelve hours, after the onset of symptoms. Follow-up tracings were obtained in all but two of these cases. In thirteen cases serial records, taken daily or at intervals of several hours, were available for study. In twenty-five cases the earliest electrocardiographic signs of infarction were high T waves, the majority of which became inverted in the healing stage of infarction. In most of the cases the high T waves were no longer present twenty-four hours after the attack. In five instances where the T waves persisted for several days, early mortality was as high as 60 per cent, as compared with 14 per cent in the cases where the high T waves underwent regression within twenty-four hours. The high T waves are thought to be part of the injury pattern. They were accompanied by abnormal elevations of S-T in twenty-one cases. In five instances elevation of S-T was either absent or within normal range. In one instance huge upright T waves were associated with marked depression of S-T. In the majority of the cases high T waves preceded the development of significant changes in the QRS complex. The latter usually appeared within twenty-four hours after the onset of symptoms, when the high T waves were already in the regressive stage. In one instance characteristic changes in QRS did not appear until six days after the attack, and in two instances they failed to develop at all. In five cases high T waves were not associated with abnormal elevation of S-T, nor with significant changes in QRS. Thus, they represented the leading diagnostic sign in the early stage of myocardial infarction.
Fast and simple distributed consensus

The problem of fault-tolerant agreement is fundamental to distributed computing. When agreement is to be reached in spite of arbitrary behavior by faulty processors, this problem is called Distributed Consensus. By requiring that the number of faulty processors be O(√n), where n is the number of processors in the system, we are able to derive two new protocols for Distributed Consensus. Both are simple and use messages that are only one bit in length, and both provide for early stopping: the fewer failures there are, the fewer rounds of communication are required. One protocol is optimal with respect to the number of rounds of communication required, and the other is asymptotically optimal with respect to the total number of message bits exchanged.
Inconsistencies in big data

We are faced with a torrent of data generated and captured in digital form as a result of the advancement of sciences, engineering and technologies, and various social, economical and human activities. This big data phenomenon ushers in a new era where human endeavors and scientific pursuits will be aided by not only human capital, and physical and financial assets, but also data assets. Research issues in big data and big data analysis are embedded in multi-dimensional scientific and technological spaces. In this paper, we first take a close look at the dimensions in big data and big data analysis, and then focus our attention on the issue of inconsistencies in big data and the impact of inconsistencies in big data analysis. We offer classifications of four types of inconsistencies in big data and point out the utility of inconsistency-induced learning as a tool for big data analysis.
Open-field behaviour in chickens: A replication revisited

In an attempt to show that the open field can still be used as a valid measure of fear, Jones (1983) has reported a failure to replicate some of our findings. The present studies show that this was due to procedural and methodological differences. For instance, we found that birds tested in a novel environment behaved quite differently from those, as in Jones' case, which were placed in one resembling the home cage. Moreover, birds housed in isolation for two days prior to testing reacted differently than those, as again in Jones' case, which were reared in isolation from hatching to the time of testing. The results were interpreted as being consistent with our view that open-field behaviour reflects a conflict between the need to reinstate contact with conspecifics on the one hand, and evade predation on the other.
Optimizing JPEG XR tile structure for fast local access

Compressed digital image technology is fundamental to a variety of consumer electronics applications. Coded images are often accessed in part rather than in whole, by accessing spatial regions of interest (ROIs). In many application architectures, the decoding process to access each ROI may occur separately - even when there are multiple such ROIs to be accessed within the same image. Moreover, some image coding schemes, such as JPEG XR and JPEG 2000, include some form of support for structuring the coded image data into distinct regions that can be referred to as tiles. The performance associated with decoding an ROI depends heavily on how the image is tiled. This paper provides information about the effects of image tile structuring on ROI access in the JPEG XR image coding context. Some guidelines are provided regarding how an image should be tiled to enable fast local access by aligning the ROI access with the tile structure to minimize decoding resource overhead.
Case-Based Problem Solving Exercises for Engineering Education

This paper describes the development of a case-behind problem solving exercise that emphasizes the managerial and the engineering aspects of a real life project. Using the real life example of a quality initiative project that was completed at a laundry detergent plant of a international company, a series of modular exercises have been developed on topics such as organizational structure, process capability, six sigma, and Taguchi methods. The exercise modules have been developed by referring to the Bloom’s six levels of cognitive learning process. This paper provides some of the highlights of the exercise development process that may be useful to educators interested in developing their own case study-based exercises or adapting the available ones to suit their needs.Copyright © 2003 by ASME
Connection Scheduling in Wavelength-Constrained Optical Time-Slotted Networks

An all-optical approach to achieve finer bandwidth granularity is to time division multiplex low capacity circuits on each wavelength channel and to switch time-wavelength slots within the network. In such a Time-Wavelength-Switched- Network (TWSN), the Time-Wavelength-Space-Routers (TWSRs) are configured to change their routing pattern on a time slot basis. Another kind of time slotted network proposed in the literature is the Time-Wavelength-Interleaved Network (TWIN), which eliminates time switching within the network by using a non-reconfigurable core and an intelligent edge utilizing a fast tunable laser to emulate fast switching. A drawback of the TWIN network is that it assigns a unique wavelength to each node in the network. Thus it requires a total of W = N wavelengths for an N-node network and hence is not scalable. In this paper we propose to design a wavelength-constrained (i.e., W < N) TWIN network with no switching (TWIN-NS) by using a multicasting strategy. We also propose a variant of the TWIN network which possesses switching capabilities only at the edge nodes (TWIN-ES), and compare the performances of these TWIN networks to that of the TWSN. We present integer linear programs and heuristic algorithms to solve the connection scheduling problem in the TWSN and the TWIN, and investigate the benefits of having a fast reconfigurable switch as opposed to a non-reconfigurable core.
Estimating technical and allocative inefficiency relative to stochastic production and cost frontiers

Abstract Earlier papers by Aiger, Lovell and Schmidt and by Meeusen and van den Broeck have considered stochastic frontier production functions. this paper extends that work by considering the duality between stochastic frontier production and cost funstions, under the assumtions of exact cost minimization (tecchnical inefficiency only) and of inexact cost minimization (technical and allocative inefficiency). We show how to measure both types of inefficiency, and the associated cost of inefficiency. The techniques are illustrated using data on steam-electric generating plants.
Transport of AgBr2−, PdBr4 2−, and AuBr4- in an Emulsion Membrane System Using K+-Dicyclohexano-18-crown-6 as Carrier

Abstract Silver, palladium, and gold have been transported through a 1.5 M KBr/toluene/0.025 M MgS2O3 (or Mg(NO2)3) emulsion membrane system as AgBr2 −, PdBr4 2− and AuBr4, respectively, using K+-dicyclohexano-18-crown-6(DCl8C6) as carrier. The transport studies are carried out in AgBr2 −, PdBr4 2−, and AuBr4 − single solutions and in AgBr2−/PdBr4 2−, AgBr2−/AuBr4 −, and PdBr4 2−/AuBr4 − binary solutions. The presence of DC18C6 in the toluene membrane is found to greatly enhance ion transport. When MgS2O3 is in the receiving phase, AuBr4 - is found to transport well even without DC18C6 in the membrane. The transport of AgBr2 −, PdBr4 2−, and AuBr4 − is greater for those systems containing MgS2O3 in the receiving phase than for those with Mg(NO3)2. In binary studies with MgS2O3 in the receiving phase, PdBr4 2− is transported selectively over AgBr2 − and AuBr4 − is transported selectively over either PdBr4 2− or AgBr2 −.
Effects of Social Bonds and Childhood Experiences on Alcohol Abuse and Smoking

Data from a national sample of 595 American adults were analyzed in an effort to evaluate simultaneously the potential effects of social bonds and childhood characteristics on smoking and alcohol use. Religious belief and belief in the importance of conformity with shared moral principles had significant negative effects on smoking, alcohol use, and alcohol abuse; commitment (satisfaction with one's socioeconomic status) inhibited smoking; and attachment (strong emotional bonds to family and friends) deterred alcohol abuse. Childhood trauma promoted both smoking and alcohol abuse.
The importance of spectroscopy in the 80–800 å region for plasma diagnostics in the solar atmosphere

The importance of the spectral range from about 80 to 800 A for determining physical conditions in different regions of the solar atmosphere is discussed. Examples are given of line ratios that may be used to determine electron densities in quiet-sun regions, active regions, and flares. The possibility of determining electron temperatures from line ratios in the EUV is considered. It is shown that profiles, as well as intensities, of spectral lines must be obtained for a proper interpretation of the spectra. Approximate parameters are provided for a solar grazing-incidence spectrograph suitable for the study of the 80-800-A wavelength region.
Significance of recurrent pain in acute type B aortic dissection.

1. Oriji GK, Keiser HR. Role of nitric oxide in cyclosporine A-induced hypertension. Hypertension 1998;32:849–855. 2. Gallego M, Villalon A, Farre A, Garcia J, Garron M, Casado S, Hernando L, Caramelo C. Mechanisms of the endothelial toxicity of cyclosporin A; role of nitric oxide, cGMP, and Ca. Circ Res 1994;74:477–484. 3. Richards N, Poston L, Hilton P. Cyclosporine A inhibits relaxation but does not induce vasoconstriction in human subcutaneous resistance vessels. J Hypertens 1989;7:1–3. 4. Akita K, Dusting G, Hickey H. Suppression of nitric oxide production by cyclosporin A and FK506A in rat vascular smooth muscle cells. Clin Exp Pharm Physiol 1994;21:231–233. 5. Vaziri N, Zhang Y, Ruzics E, Maleki P, Ding Y. Depressed renal and vascular nitric oxide synthase expression in cyclosporine-induced hypertension. Kidney Int 1998;54:482–491. 6. Oriji GK. Nitric oxide in cyclosporine A-induced hypertension: endothelin receptors gene expression. Prostaglandins Leukotrienes Essential Fatty Acids 1999;61:41–44. 7. Prieto M, Escallada R, Cobo M, Cotorruelo J, Morales P, de Francisco A, Rodrigo E, Sanz S, Arias M. Oral arginine restores endothelium-dependent vasodilation in cyclosporine treated rats. Transplant Proc 1997;29:1244–1245. 8. Bartholomeusz B, Hardy K, Nelson A, Phillips P. Modulation of nitric oxide improves cyclosporin A-induced hypertension in rats and primates. J Human Hyperten 1998;12:839–844. 9. Tangphao O, Grossmann M, Chalon S, Hoffman BB, Blaschke TF. Pharmacokinetics of intravenous and oral L-arginine in normal volunteers. J Clin Pharmacol 1999;47:261–266. 10. Mehta S, Stewart D, Langleben D, Levy R. Short-term pulmonary vasodilatation with L-arginine in pulmonary hypertension. Circulation 1995;92:1539– 1545. 11. van Haeften TW, Konings CH. Arginine pharmacokinetics in humans assessed with an enzymatic assay adapted to a centrifugal analyzer. Clin Chem 1989;35:1024–1026.
The effects of anoxia on the nuclear morphology of thymus cells in normal and irradiated rats

Incubation of thymocytes in the anoxic thymus of the dead rat for periods longer than 30 min damages them. This damage causes no visible change in nuclear structure if the cells remain in the anoxic thymus, but when they are released therefrom and suspended in vitro their nuclei become structurally homogeneous (“pycnotic”). The fraction of cells which subsequently lose their nuclear structure in vitro is proportional to the concentration of inorganic phosphate in the medium. The amount of damage inflicted upon the cells during incubation in the anoxic thymus can be reduced by introducing tris(hydroxymethyl)aminomethane (Tris) buffer into the animal before its death. The establishment of primary radiation damage in thymocytes can be considerably reduced by incubation in the anoxic thymus of a Tris-treated, dead animal during the first 2 h after irradiation. The development of radiation damage cannot be reduced if the 2-h sojourn in the anoxic thymus is delayed until 30 min after irradiation. The beneficial effect of postirradiation oxygen deprivation is at least equal to that produced by the classical “oxygen effect”.
Film-induced tourism as a vehicle for destination marketing: is it worth the efforts?

ABSTRACT This study examined the impact of a film on the featured destination's image and travel intentions through comparing the results of a one-group pretest-posttest quasi-experiment. Then, the effect of destination attributes and overall image on travel intentions is examined simultaneously through path analysis. The results indicate that the role of the overall image as a mediating variable is not significant as respondents relied more on specific destination image attributes on their intention to visit. This was even more prominent after the viewing of the film. The overall image had the strongest direct effect on visit interest in future for both pretest and posttest.
A new importance function for particle filtering and its application to blind detection in flat fading channels

Particle filtering has drawn much attention in recent years due to its capacity to handle nonlinear and non-Gaussian problems. One crucial issue in particle filtering is-the selection of importance function. In this paper, we propose a new type of importance function, which possess advantages over both the posterior and the prior importance functions. In addition, we demonstrate the use of the proposed importance function in blind detection in flat fading channels. Simulation results show its efficiency and performance.
Das Projekt „Population and Development“ von Rotary International

Auf Anregung des Sudwestdeutschen Rotary Distrikts beschaftigt sich auch Rotary International seit 1988 mit dem Wachstum der Weltbevolkerung. Rotary folgt damit auch dem Aufruf der Weltbevolkerungskonferenz von 1994 an die Nichtregierungsorganisationen, sich an deren Programm zu beteiligen. Seit 1994 gibt es ein Familienplanungsprojekt in Nigeria, an dem sich deutsche Rotarier sowohl durch direkte Beratung und Leitung als auch durch finanzielle Unterstutzung beteiligen. Sie treten dafur ein, das auch die Menschen in den Entwicklungslandern die vor uber 30 Jahren von den Vereinten Nationen verkundeten Grundrechte auf Information und den Zugang zu Familienplanungsdiensten in Anspruch nehmen konnen. Bei dem Aufbau der Organisationsstrukturen in Nigeria kann Rotary auf kompetente Fachkrafte, erprobte flachendeckende Infrastrukturen und Erfahrungen zuruckgreifen, die bei fruheren Projekten gesammelt werden konnten.
Foot ulcer risk and location in relation to prospective clinical assessment of foot shape and mobility among persons with diabetes

Abstract Aims We assessed baseline clinical foot shape for 2939 feet of diabetic subjects who were monitored prospectively for foot ulceration. Methods Assessments included hammer/claw toes, hallux valgus, hallux limitus, prominent metatarsal heads, bony prominences, Charcot deformity, plantar callus, foot type, muscle atrophy, ankle and hallux mobility, and neuropathy. Risk factors were linked to ulcer occurrence and location via a Cox proportional hazards model. Results Hammer/claw toes (hazard ratio [HR] (95% confidence interval [CI])=1.43 (1.06, 1.94) p =0.02), marked hammer/claw toes (HR=1.77 (1.18, 2.66) p =0.006), bony prominences (HR=1.38 (1.02, 1.88), p =0.04), and foot type (Charcot or drop foot vs. neutrally aligned) (HR=2.34 (1.33, 4.10), p =0.003) were significant risk factors for ulceration adjusting for age, body mass index, insulin medication, ulcer history and amputation history. With adjustment for neuropathy only hammer/claw toes (HR=1.40 (1.03, 1.90), p =0.03) and foot type (HR=1.76 (1.04, 3.04), p =0.05) were significantly related to ulceration. However, there was no relationship between ulcer location and foot deformity. Conclusions Certain foot deformities were predictive of ulceration, although there was no relationship between clinical foot deformity and ulcer location.
Representations at fixed points of smooth actions of cyclic groups

Abstract Let G be a cyclic group acting smoothly on a connected closed manifold M with nonempty fixed point set F . Let Θ x be the representation of G defined by the induced G linear action on the tangent space T x ( M ) at x ϵ F . In this paper, we study the relations between the cohomology of M and the equivalent representations of G at fixed points.
A new species of Ommatius Wiedemann from Brazil (Diptera: Asilidae) with notes on the Ommatius costatus species group

Abstract Ommatius tractus, n. sp., from Santo Amaro, Brazil, is described, illustrated, and diagnosed. A modified key is presented to aid in its identification. Ommatius spatulatus Curran is placed in the species group and is reported from Argentina for the first time. Ommatius riali Vieira, Castro & Bravo is established as a New Synonym of O. spatulatus Curran. A check list of the costatus species group is also included.
Convex programs having some linear constraints

The problem of concern is the minimization of a convex function over a normed space (such as a Hilbert space) subject to the constraints that a number of other convex functions are not positive. As is well known, there is a dual maximization problem involving Lagrange multipliers. Some of the constraint functions are linear, and so the Uzawa, Stoer, and Witzgall form of the Slater constraint qualifications is appropriate. A short elementary proof is given that the infimum of the first problem is equal to the supremum of the second problem.
Preliminary Efficacy of a Cognitive-Behavioral Treatment Program for Anxious Youth with Autism Spectrum Disorders

Anxiety is a commonly occurring psychiatric concern in adolescents with autism spectrum disorders (ASD). This pilot study examined the preliminary efficacy of a manual-based intervention targeting anxiety and social competence in four adolescents with high-functioning ASD. Anxiety and social functioning were assessed at baseline, midpoint, endpoint, and 6 months following treatment. Treatment consisted of cognitive-behavioral therapy, supplemented with parent education and group social skills training. The treatment program was effective in reducing anxiety in three of the four subjects and improving the social skills in all four subjects. Recommendations for the assessment and treatment of anxiety youth with ASD such as use of self-report measures to complement clinician and parent-reports and adaptations to traditional child-based CBT, are offered.
Nondispersive propagation skew in iterative neural network and optical feedback processors

Although certain iterative optical processors promise algorithmic convergence at the speed of light, little attention is normally given to the consequences of different path lengths required within the processor on the processor performance. The resulting clock skew can have significant degrading effects on the predicted accuracy, stability, and speed of the processor. A similar problem occurs in iterative asynchronous artificial neural networks when, for example, the time delay between two neurons is proportional to their physical separation. In this paper, we show that in the absence of temporal dispersion, certain iterative algorithms have stable steady-state solutions that are independent of clock skew. Examples include stable linear feedback and feedback using soft (slowly varying) nonlinearities. Both are special cases of using a contractive operation in the feedback path. Such processing algorithms can have stable steady-state solutions that are independent of clock skew. Feedback using hard nonlinearities, on the other hand, can result in either an oscillatory or a steady-state solution that depends on the clock skew.
Role of the azomethine in the dimerization of cycloserine by aldehydes.

Abstract Further elucidation of the mechanism by which an aldehyde converts cycloserine (I) into its dimer is reported. A “prior dimerization” mechanism is eliminated and a carbonolamine is shown to be a possible intermediate when “electrophilic” aldehydes react. Azomethine formation is shown to be a necessary step and an aminal intermediate nicely explains the results of some experiments involving racemic reactants. Both the medium and the nature of the aldehyde determine the preferred pathway of dimerization. Attempts to prepare a d -cycloserine pyridoxal Schiff base are described.
Interannual variability of NDVI over Africa and its relation to El Niño/Southern Oscillation

Abstract The array of Normalized Difference Vegetation Index (NDVI) products now being derived from satellite imagery open up new opportunities for the study of short and long-term variability in climate. Using a time series analysis procedure based on the Principal Components transform, and a sequence of monthly Advanced Very High Resolution Radiometer (AVHRR)-derived NDVI imagery from 1986 through 1990, we examine trends in variability of vegetation greenness for Africa for evidence of climatic trends. In addition to the anticipated seasonal trends, we identify signals of interannual variability. The most readily identified is one that periodically affects Southern Africa. It is shown that the temporal loadings for this component exhibit a very strong relationship with the El Nino/Southern Oscillation (ENSO) Index derived from atmospheric pressure patterns in the Pacific, Pacific sea surface temperature (SST) anomalies, and with anomalous Outgoing Longwave Radiation (OLR). However, we have also detected...
Compositional effects of fluids on spreading, adhesion and wettability in porous media

Abstract The interfacial phenomena of spreading and adhesion of fluids on rock surfaces have serious implications because of their impact on production strategy and oil recovery. The present study reports new experimental data on the effect of brine dilution and surfactant addition on spreading and adhesion behavior of Yates crude oil on dolomite surfaces. Spreading and adhesion have been characterized through measurements of oil–water interfacial tension (IFT) and dynamic (water-advancing and receding) contact angles. The interfacial tension was measured using computerized axisymmetric drop shape analysis (CADSA) technique, which was calibrated against the well-known du Nuoy Ring technique. The dual-drop dual-crystal (DDDC) technique and the Wilhelmy plate technique have been used to measure dynamic contact angles. In order to study the effect of brine dilution, Yates reservoir brine was mixed with deionized water (DIW) in various proportions. The oil–water IFT initially decreased as the volume percent of brine in the mixture decreased but IFT increased with further dilution of reservoir brine with DIW. A decreasing trend was observed in the behavior of water-advancing contact angle with brine dilution. However, a strange behavior of spreading of crude oil drop against brine on the dolomite surface (with large water-receding contact angles) was observed at certain brine dilutions. This spreading of crude oil appears to be related to interfacial tension in a manner similar to Zisman’s observations in solid–liquid–vapor systems. The use of surfactants to enhance oil recovery through reduction in IFT is well known in the industry. However, this study examines the capability of certain surfactants to alter wettability in addition to reducing IFT. For the Yates reservoir rock-fluids system, an ethoxy alcohol surfactant altered the strongly oil-wet nature (advancing angle of 158°) to water-wet (advancing angle of 39°) at a concentration of 3500 ppm. While the DDDC technique yielded significant changes in wettability due to surfactant addition, the Wilhelmy Plate technique remained insensitive throughout the range of surfactant concentrations. The practical significance of this study is that it identifies two simple modes through surfactant addition and brine dilution to alter wettability to minimize capillary trapping of oil.
Pyrolysis gas chromatography-mass spectrometry of polychlorinated biphenyls on sediment

Polychlorinated biphenyls (PCBs) are common environmental contaminants which were freely employed for many years in numerous industrial applications but whose use has now been regulated. Many analytical schemes for monitoring these materials in environmental samples have been developed over the last decades, however, PCBs remain difficult analytical subjects. Most protocols rely on a combination of wet chemical pre-analytical isolation and purification whose complexity depends on the sample matrix. The time required for these manipulations may greatly hamper efforts directed towards emergency cleanup of accidental or illicit contamination of the environment. Thus, a clear need exists for methods which will allow rapid analysis of relatively intransigent samples for PCB contamination. Preliminary experiments directed to assessing the use of pyrolysis/gas chromatography/mass spectrometry in determining PCB contamination of soils and sediments are reported. In these experiments pyrolytic desorption at 1000/sup 0/C during 10 sec was used to completely replace more lengthy wet chemical manipulations.
Nonparametric Empirical Bayes Estimation of the Matrix Parameter of the Wishart Distribution

We consider independent pairs (X1, ?1), (X2, ?2), ?, (Xn, ?n), where each?iis distributed according to some unknown density functiong(?) and, given?i=?,Xihas conditional density functionq(x??) of the Wishart type. In each pair the first component is observable but the second is not. After the (n+1)th observationXn+1is obtained, the objective is to estimate?n+1corresponding toXn+1. This estimator is called the empirical Bayes (EB) estimator of?. An EB estimator of?is constructed without any parametric assumptions ong(?). Its posterior mean square risk is examined, and the estimator is demonstrated to be pointwise asymptotically optimal.
EPR evidence for a single electron transfer mechanism in reactions of aromatic ketones with lithium amides

Abstract Direct spectroscopic evidence (EPR) supporting a single electron transfer mechanism in the reaction of lithium amides with aromatic ketones is presented.
Relating phosphorus uptake to changes in transient storage and streambed sediment characteristics in headwater tributaries of Valley Creek, an urbanizing watershed

Summary Phosphorus uptake dynamics were examined in two small streams in the Valley Creek watershed, located in an urbanizing area approximately 30 km west of Philadelphia, Pennsylvania, USA. The goal of this research was to examine how phosphorus uptake is influenced by temporal changes in bed sediment characteristics and transient storage in streams within an urbanizing watershed. We conducted tracer studies with a conservative solute, observed phosphorus uptake in situ and in laboratory experiments, and measured fine bed sediment grain size distributions and chemical compositions at both sites. At the Morehall Rd. site, the total laboratory and in situ uptake rates were related to the silt–clay ( d d in situ uptake rate was also related to the sediment magnesium content and the transient storage exchange rate and area. At the Sheldrake Rd. site, the phosphorus uptake rates observed in situ and in the laboratory were not significantly related to any of the measured stream or sediment characteristics. However, the areal average uptake (uptake flux), was related to the transient storage exchange rate. In addition, the abiotic contribution to in situ uptake was evaluated by comparing the in situ and laboratory measured uptake rates. The total abiotic in situ uptake rate was found to be related to the bed sediment silt–clay content and the transient storage residence time, while the abiotic uptake flux was related to the transient storage residence time. Overall, these urbanizing streams were less efficient at removing phosphorus from the water column than forested streams in non-urban settings.
Phonemic structures of delayed phonological systems

The phonemic inventories of 30 children (aged 3;4-5;7) with phonological delays were examined in terms of featural distinctions in order to address universal vs. individual accounts of acquisition. Phonetic inventories of these same children were also identified for comparison purposes. Across children, four hierarchical and implicationally related types of phonemic inventory were identified. The typology uniquely captured common distinctions maintained by all children, and at the same time, allowed for individual differences in the specific phonemic composition of each system. These cross-sectional results have theoretical implications for the longitudinal course of phonemic acquisition. In particular, children appear to have a number of linguistic choices that relate to the course, the specifics, and the mechanism of change in acquisition.
Initial clinical experience with use of ureteral access sheaths in the diagnosis and treatment of upper tract urothelial carcinoma.

Objective To describe our experience with ureteral access sheaths in the diagnosis and treatment of upper tract urothelial carcinoma. Methods We retrospectively identified a patient cohort who underwent ureteroscopy for suspicion of upper tract urothelial carcinoma and identified those with placement of a ureteral access sheath. Records were reviewed for demographic information, comorbidity data, operative complications, and pathology results. The histologic grade of ureteroscopic biopsies and nephroureterectomy specimens were evaluated for concordance. Results A total of 125 patients underwent 235 procedures for known or suspected upper tract urothelial carcinoma. Access sheaths were used in patients in whom significant urothelial lesions were noted in the proximal upper urinary tract. A total of 64 patients underwent 85 sheath-inclusive procedures. Sheath deployment was successful in 83 (97.6%) of the 85 procedures. Biopsies yielded specimen adequate for histopathologic diagnosis in 75 (90.4%) of 83 cases. No ureteral access sheath-related complications were noted. Of the 125 patients, 34 underwent removal of 35 renal units. The concordance of tumor grade between biopsy and nephroureterectomy specimens was 88.6% ( P = .0002). Conclusion Ureteral access sheaths are safe for use in the diagnosis and treatment of upper tract urothelial carcinoma. Sheath placement facilitated the acquisition of multiple biopsy specimens adequate for histopathologic evaluation. Our technique precluded the need for repeat ureteroscopy to establish a diagnosis. Biopsies obtained through an access sheath were highly predictive of tumor grade in nephroureterectomy specimens.
Polymer-assisted chemical solution approach to YVO4:Eu nanoparticle networks

Phosphor YVO4:Eu nanoparticle networks were synthesized using water soluble ethylenediaminetetraacetic acid (EDTA) and polyethyleneimine (PEI) as binding ligands. The morphology, particle size, BET surface area, and photoluminescence of YVO4:Eu processed at different annealing temperatures (500, 600, 700, and 800 °C) and EDTA/PEI mass ratios (1 : 4, 1 : 2.5, 1 : 2, 1 : 1.5, 1 : 1, 2 : 1, and 4 : 1) were determined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, fluorescence spectrophotometer, and N2 adsorption and desorption. The red emission was observed with increasing the annealing temperature. Importantly, the nanoparticles did not aggregate at high annealing temperatures up to 800 °C. The smallest size of the YVO4:Eu nanoparticles is about 18 nm and the surface area is 35 m2 g−1 with the EDTA/PEI mass ratios of 1 : 1–2.5.
Culture War Confessionals: Conflicting Accounts of Christianity, Violence, and Mixed Martial Arts

The micro-foundations of the American culture wars can be located by investigating informal accounts, narratives, and other forms of public discourse. We focus on the accounts of self-proclaimed Christian believers who are Mixed Martial Arts (MMA) fans in order to uncover the nuanced ways they address the internal conflict between their religious beliefs and their leisure practices. Because American culture consists of multiple moral orders, individuals seek answers to questions about right and wrong in a great variety of social fields, including popular culture. By analyzing the accounts of Christian MMA fans who purposively use the Internet as a confessional device for claims making, we show that the culture wars are as much about conflicts within individuals as they are about conflicts between them. The culture wars are experienced by individuals offering and being offered confessional accounts of morality. We argue that these accounts and related boundary work are externalized products of an internali...
Inhibition of F-Actin Cycling in Rbl Mast Cells Prevents Endosome Acidification but not Internalization of Antigen-Crosslinked IgE Receptor Complexes

Previous studies have implicated roles for the actin cytoseleton in endocytosis via clathrin-coated pits, as well as in antigen-stimulated endocytosis of immunoglobulin-E (IgE) receptors (Ra et al., Eur. J. Immunol. 19:1771, 1989). To monitor endocytosis in real time, we use a fluorescence assay that reports pH-dependent quenching of FITC-IgE. We find that micromolar concentrations of either cytochalasin D or latrunculin A, inhibitors of actin polymerization, as well as jasplakinolide, a stabilizer of F-actin polymerization, all prevent this antigen-stimulated FITC quenching due to endosomal acidification. Under these conditions, crosslinked IgE receptors appear localized in endosomes by confocal imaging, despite the lack of acid-dependent FITC quenching. A quantitative flow cytometry assay for surface-available IgE shows that greater than 60% of these IgE receptor complexes are internalized in response to antigen crosslinking in the presence or absence of these inhibitors of actin polymerization cycling. After 20 min at 37oC with antigen, we observe partial co-localization of IgE receptor-containing endosomes with a lysosomal marker, indicating normal endosomal trafficking of these complexes in the presence or absence of these agents. Addition of latrunculin A or cytochalasin D after antigen stimulated endocytosis causes rapid, partial reversal of endosomal acidification monitored by FITC-IgE, suggesting dynamic regulation of this process by the actin cytoskeleton. In contrast, secretory lysosomes labeled with FITC-dextran by fluid-phase pinocytosis maintain normal acidification in cells treated with these agents. In ongoing experiments we are investigating the molecular mechanism for cytoskeletal regulation of endosomal acidification.
Cross-Language Nonword Repetition by Bilingual and Monolingual Children

Purpose Identifying children with primary or specific language impairment (LI) in languages other than English continues to present a diagnostic challenge. This study examined the utility of Englis...
An Analysis of the Intercorrelations Among Spectral Amplitudes in the EEG: A Generator Study

The objective of this study is to explore the physiological sources of covariation between multiple narrow-band EEG spectral amplitudes with an aim toward parsimonious modeling of the observed intercorrelations. Specifically, a factor-analytic model describing the intercorrelations among 25 spectral amplitudes, at 1-Hz increments from 1 to 25 Hz, is presented. This method is applied to the EEGs obtained from a group of five subjects controlled for age, sex, state of consciousness, and recording dipole. The subjects were studied in waking and sleeping states in order to examine how this model would represent such physiological changes.
High speed imaging in fundamental and applied combustion research

Abstract This overview presents examples of applications of high frame rate imaging diagnostics in fundamental and applied combustion research. Progress in the performance of high frame rate digital cameras and high repetition rate lasers enabled the development of a range of new imaging diagnostics for measurements of velocities, concentrations and temperatures. Camera frame rates and storage capacities are now adequate to resolve and follow time scales spanning six orders of magnitude while camera chip size limitations restrict the spatial dynamic range to about three orders of magnitude. High-speed imaging studies of mixing processes, flame stabilization, ignition and extinction and the coupling of acoustic and chemical processes in turbulent flames and internal combustion engines have produced a wealth of new understanding, contributing also to the development of predictive models. Future progress in designing and operating cleaner and more efficient combustion device hinges on our ability to push operating conditions to leaner mixtures and often to higher pressures. There, small variations in boundary conditions, e.g. flow patterns or the formation of a fuel spray, might lead to combustion failures that can range from acoustic noise in a jet flame, a misfire in an automobile engine, to lean-blow-out of an aircraft gas turbine engine; from nuisance to catastrophe. High-speed imaging in turbulent flames and internal combustion engines allowed capturing and identifying detrimental conditions that might be rare in occurrence and defining in leading to failure. The examples presented in this review illustrate the status of diagnostic capabilities, show sample results, and examine some future directions.