cssi/SciSciGPT-SciSciNet huggingface dataset:
Lipoxygenase inhibitors exert secretagogue-specific effects on mast cell exocytosis

Abstract The lipoxygenase inhibitors HTYA (5,8,11,14-henicosatetraynoic acid, 25–150 μM) and ITYA (4,7,10,13-icosatetraynoic acid, 25–75 μM), inhibited histamine secretion from rat mast cells evoked by concanavalin A but not that elicited by compound 48/80 or polymyxin B. Arachidonic acid (100 μM) did not inhibit concanavalin A-induced histamine secretion. The results are consistent with the notion that lipoxygenase inhibitors affect an early stage of stimulus-secretion coupling in the mast cell, peculiar to antibody-directed secretagogues, perhaps that involving calcium influx.
Identification of Septal Ischemia During Exercise By Q-Wave Analysis: Correlation With Coronary Angiography

Septal Q-wave amplitudes were studied in lead CM 5 to evaluate its utility in predicting segmental coronary artery pathoanatomy. Q-wave amplitudes were measured in 41 patients with coronary artery disease (CAD) before and immediately after treadmill exercise. All patients studied had either significant single-vessel CAD (> 70% diameter reduction) or normal coronary anatomy; 13 had left anterior descending (LAD) CAD, 8 had right coronary occlusions, 8 had left circumflex (LC) CAD, and 12 had angiographically normal coronary arteries. Septal Q-wave amplitude measurements at rest and during peak exercise were recorded in 0.5 mm increments and classified as increasing in 20 patients, decreasing in 8, and no change in 13 with exercise. All 13 patients with isolated LAD narrowing had either no change (5 patients) or a decrease (8 patients) in the septal Q wave with exercise. Statistical analysis revealed 62% sensitivity and 100% specificity for single LAD narrowing if a decreasing Q wave was noted with exercise. Patients with isolated right or LC CAD or normal coronary anatomy had mixed septal Q-wave responses to exercise. Only patients with LAD narrowing had reductions in Q-wave amplitude with treadmill exercise. This finding suggests that low Q-wave voltage and its failure to increase after exercise imply abnormal septal activation, reflecting loss of contraction associated with ischemia from LAD narrowing.
Detection of microregional hypoxia in mouse cerebral cortex by two-photon imaging of endogenous NADH fluorescence.

The brain's ability to function at high levels of metabolic demand depends on continuous oxygen supply through blood flow and tissue oxygen diffusion. Here we present a visualized experimental and methodological protocol to directly visualize microregional tissue hypoxia and to infer perivascular oxygen gradients in the mouse cortex. It is based on the non-linear relationship between nicotinamide adenine dinucleotide (NADH) endogenous fluorescence intensity and oxygen partial pressure in the tissue, where observed tissue NADH fluorescence abruptly increases at tissue oxygen levels below 10 mmHg1. We use two-photon excitation at 740 nm which allows for concurrent excitation of intrinsic NADH tissue fluorescence and blood plasma contrasted with Texas-Red dextran. The advantages of this method over existing approaches include the following: it takes advantage of an intrinsic tissue signal and can be performed using standard two-photon in vivo imaging equipment; it permits continuous monitoring in the whole field of view with a depth resolution of ~50 μm. We demonstrate that brain tissue areas furthest from cerebral blood vessels correspond to vulnerable watershed areas which are the first to become functionally hypoxic following a decline in vascular oxygen supply. This method allows one to image microregional cortical oxygenation and is therefore useful for examining the role of inadequate or restricted tissue oxygen supply in neurovascular diseases and stroke.
The effects of dislocation density and crystal orientation on the kinetics of the catalyzed oxidation of ethylene over a single crystal of silver

Abstract A study of the effects of dislocation density and crystal orientation on the kinetics of the catalyzed oxidation of ethylene to carbon dioxide over a single crystal of silver was carried out in a continuous-flow microreactor. A feed composition of approximately 20% ethylene and 80% oxygen was used for all reactor runs, and the temperature was varied from 250 to 350 °C at atmospheric pressure. The dislocation density was increased by introducing a strain of 0.8% in the crystal, and the crystal orientation was chosen by adopting as the catalytic surface either the (100), (110), or (111) crystal plane. Results indicated that the crystal orientation had essentially no effect on the reaction rate but that straining the crystals caused a significant decrease in the rate. At 260 °C and a total pressure of 740 mm Hg for a reactant mixture of nominally 20% ethylene and 80% oxygen, the rate of production of carbon dioxide was 5.6 × 10 −8 mol/min cm 2 for the non-strained crystals and 2.8 × 10 −8 mol/ min cm 2 for the strained crystals. The conclusion is that dislocations do not act as active sites for the oxidation of ethylene to carbon dioxide but effect a change in the nature of the chemical structure of the surface to reduce the rate of oxidation.
Analysis of SC networks using continuous-time four-port equivalents

A method of deriving a continuous-time equivalent of an SC network is considered. This method is based on LDI transformation.
DNA replication and transcription direct a DNA strand bias in the process of targeted gene repair in mammalian cells

The repair of point mutations can be directed by modified single-stranded DNA oligonucleotides and regulated by cellular activities including homologous recombination, mismatch repair and transcription. Now, we report that DNA replication modulates the gene repair process by influencing the frequency with which either DNA strand is corrected. An SV40-virus-based system was used to investigate the role of DNA synthesis on gene repair in COS-1 cells. We confirm that transcription exerts a strand bias on the gene repair process even when correction takes place on actively replicating templates. We were able to distinguish between the influences of transcription and replication on strand bias by changing the orientation of a gene encoding enhanced green fluorescent protein relative to the origin of replication, and confirmed the previously observed bias towards the untranscribed strand. We report that DNA replication can increase the level of untranscribed strand preference only if that strand also serves as the lagging strand in DNA synthesis. Furthermore, the effect of replication on gene repair frequency and strand bias appears to be independent of certain mismatched base pairs and oligonucleotide length.
Optimal property taxation in the presence of interregional capital mobility

Abstract A single region's optimal property tax policy is examined in a model with interregional capital mobility. In this model, property taxation is used to finance local public expenditures. Different tax rates may be imposed on property used to produce goods which are traded between regions and property used to produce nontraded goods (e.g., residential property). The key determinants of the difference between the optimal tax rates are identified, and it is argued that there exists a bias towards relatively low tax rates on property used to produce traded goods. The role of labor mobility is also investigated.
Genetic Basis of Clinical Catecholamine Disorders

Norepinephrine and epinephrine are critical determinants of minute-to-minute regulation of blood pressure. Here we review the characterization of two syndromes associated with a genetic abnormality in the noradrenergic pathway. In 1986, we reported a congenital syndrome of undetectable tissue and circulating levels of norepinephrine and epinephrine, elevated levels of dopamine, and absence of dopamine-beta-hydroxylase (DBH). These patients appeared with ptosis and severe orthostatic hypotension and lacked sympathetic noradrenergic function. In two persons with DBH deficiency, we identified seven novel polymorphisms. Both patients are compound heterozygotes for a variant that affects expression of DBH protein via impairment of splicing. Patient 1 also has a missense mutation in DBH exon 2, and patient 2 carries missense mutations in exons 1 and 6. Orthostatic intolerance is a common syndrome affecting young women, presenting with orthostatic tachycardia and symptoms of cerebral hypoperfusion on standing. We tested the hypothesis that abnormal norepinephrine transporter (NET) function might contribute to its etiology. In our proband, we found an elevated plasma norepinephrine with standing that was disproportionate to the increase in levels of dihydroxphenylglycol, as well as impaired norepinephrine clearance and tyramine resistance. Studies of NET gene structure revealed a coding mutation converting a conserved alanine residue in transmembrane domain 9 to proline. Analysis of the protein produced by the mutant cDNA demonstrated greater than 98% reduction in activity relative to normal. The finding of genetic mutations responsible for DBH deficiency and orthostatic intolerance leads us to believe that genetic causes of other autonomic disorders will be found, enabling us to design more effective therapeutic interventions.
Exponentially smoothed regression analysis for demand forecasting

Abstract This article proposes a new technique for estimating trend and multiplicative seasonality in time series data. The technique is computationally quite straightforward and gives better forecasts (in a sense described below) than other commonly used methods. Like many other methods, the one presented here is basically a decomposition technique, that is, it attempts to isolate and estimate the several subcomponents in the time series. It draws primarily on regression analysis for its power and has some of the computational advantages of exponential smoothing. In particular, old estimates of base, trend, and seasonality may be smoothed with new data as they occur. The basic technique was developed originally as a way to generate initial parameter values for a Winters exponential smoothing model [4], but it proved to be a useful forecasting method in itself. The objective in all decomposition methods is to separate somehow the effects of trend and seasonality in the data, so that the two may be estimated independently. When seasonality is modeled with an additive form (Datum = Base + Trend + Seasonal Factor), techniques such as regression analysis with dummy variables or ratio-to-moving-average techniques accomplish this task well. It is more common, however, to model seasonality as a multiplicative form (as in the Winters model, for example, where Datum = [Base + Trend] ∗ Seasonal Factor). In this case, it can be shown that neither of the techniques above achieves a proper separation of the trend and seasonal effects, and in some instances may give highly misleading results. The technique described in this article attempts to deal properly with multiplicative seasonality, while remaining computationally tractable. The technique is built on a set of simple regression models, one for each period in the seasonal cycle. These models are used to estimate individual seasonal effects and then pooled to estimate the base and trend. As new data occur, they are smoothed into the least-squares formulas with computations that are quite similar to those used in ordinary exponential smoothing. Thus, the full least-squares computations are done only once, when the forecasting process is first initiated. Although the technique is demonstrated here under the assumption that trend is linear, the trend may, in fact, assume any form for which the curve-fitting tools are available (exponential, polynomial, etc.). The method has proved to be easy to program and execute, and computational experience has been quite favorable. It is faster than the RTMA method or regression with dummy variables (which requires a multiple regression routine), and it is competitive with, although a bit slower than, ordinary triple exponential smoothing.
The effect of solar array degradation on electric propulsion spacecraft performance.

Current estimates of solar-electric-propulsion spacecraft performance are based upon a solar-array output power which is degraded by approximately 10-13% to account for possible losses caused by proton, electron and micrometeorite damage. Past studies have used a worst case analysis in which the maximum degradation was taken to occur at the beginning of the mission. This paper presents a comparison of mission studies using a hypothetical exponential decrease in power with time, with those using a sudden degradation of solar power. These comparisons indicate that the performance gain by using a time varying degradation during the mission is quite small for outbound missions in the solar system. In addition an indication of the power allocation strategy to be followed during a mission is presented.
Optimization of queuing theory wait time through multi-skilled worker assignments

Operator allocation is a key aspect of manufacturing with both direct and indirect implications on system performance. Resource capacity must be managed carefully while still considering human factors like probability of operator error, job satisfaction, and worker (and skill) retention. In many cases human resources are flexible in their ability to handle various types of jobs, and this condition is favorable because it makes the system more robust in the face of disruptive events. Unfortunately, the benefits of worker flexibility may not be fully understood or utilized on account of the many sources of variability that exist and confuse the outcome of worker allocation decisions. The purpose of this work is to quantify the effect of varying rework rates of differently-trained employees working on multiple products. Subsequently, the time that inventory spends waiting in queue is minimized through optimization of worker placement.
Insights into immigration and social class at Machu Picchu, Peru based on oxygen, strontium, and lead isotopic analysis

Abstract The Inca Empire (AD 1438–1532) made common practice of relocating individuals, households and entire communities throughout their expansive realm for different reasons depending on subjects' assigned social class. Reconstructing patterns of immigration at Inca-period sites could therefore permit some estimation of the social class(es) among their constituents, and thereby provide insights into the functional dynamics of Inca political economy. However, this is a difficult endeavor using only archaeological lines of evidence. This study presents oxygen, strontium and lead isotopic results from the well-preserved, well-contextualized skeletal population ( N = 74) from the Inca site of Machu Picchu, Peru. Isotopic data are used to reconstruct patterns of immigration at the site, which are in turn used to directly estimate the social class of the population. The resulting isotopic data are widely distributed with no apparent modality, matching the expected distribution of a particular class of nonelite retainers. A novel application of multivariate statistics coupled with geological and faunal isotopic reference data also permits tentative estimation of individuals' regions of origin. This study provides empirical and analytical frameworks for future research in reconstructing residential movement and class dynamics in the late prehistoric Andes.
Aging and resistance to Trichinella spiralis infection following xenobiotic exposure.

: Aging is accompanied by well-documented physiological changes, including alterations in the immune system that can lead to reduced resistance to a variety of infectious agents. We tested the hypothesis that immunosenescence exacerbates the immunosuppressive effect of xenobiotics. If proven true, a given dose of an immunosuppressive xenobiotic would cause greater suppression of host resistance in an aged population.
Regulation of Galanin Gene Expression in Gonadotropin- Releasing Hormone Neurons during the Estrous Cycle of the Rat*

Galanin is colocalized with GnRH in neurons of the hypothalamus and basal forebrain of female rats, and this neuropeptide may play a role in the generation of the midcycle surge of gonadotropin secretion. We tested the hypothesis that galanin gene expression in GnRH cells increases during proestrus. To accomplish this, we killed groups of adult female rats at 1200 and 1800 h on the day of proestrus as well as at 1800 h on the day of estrus and used double labeling in situ hybridization and image analysis to estimate and compare the levels of galanin mRNA in cells coexpressing GnRH mRNA. GnRH mRNA was detected with an antisense cRNA probe labeled with the hapten digoxigenin, while the galanin cRNA probe was labeled with 35S and detected by autoradiography. There was no significant difference in the total number of GnRH cells identified in each animal in any of the different groups in any experiment. The relative number of silver grains over these cells, reflecting galanin mRNA content in GnRH neurons (iden...
The use of flowlines to simplify routing complexity in two-stage flowshops

Flexible manufacturing systems are often designed as flowshops supported by automated material handling devices that facilitate routing among any two processors of adjacent stages. This routing structure is complex, and results in excessive capital investment and costs of management. In this paper we propose a decomposition of two-stage flowshops into smaller independent flowlines that allow for unidirectional routing only. We solve optimally the problem of minimizing makespan on two parallel flowlines, by means of a Dynamic Programming algorithm (DP). Based on DP we develop lower bounds on the throughput performance of environments that consist of more than two flowlines. We present several heuristic algorithms and report their optimality gaps. Using these algorithms, we show that the decomposition of two stage flowshops with complicated routing into flowline-like designs with unidirectional routing is associated with minor losses in throughput performance, and hence significant savings in material handling costs.
Comparison of flow and velocity during dynamic autoregulation testing in humans.

We compared relative changes in middle cerebral artery velocity and internal carotid artery flow during autoregulation testing to test the validity of using transcranial Doppler recordings of middle cerebral artery velocity to evaluate cerebral autoregulation in humans.Seven human volunteers had dynamic autoregulation tested during surgical procedures that included exposure of the internal carotid artery. The mean arterial blood pressure and middle cerebral artery velocity spectral outline (Vmax), using transcranial Doppler, and ipsilateral internal carotid artery flow, using an electromagnetic flowmeter, were continuously and simultaneously recorded during transient sharp decreases in blood pressure that were induced by rapid deflation of thigh blood pressure cuffs. The resulting responses of velocity in the middle cerebral artery and flow in the internal carotid artery were compared.Moderate decreases in blood pressure evoked responses in cerebral autoregulation. There were no significant (P = .97) diff...
Semi-empirical model for helical magnetocumulative generators

Summary form only given. A semi-empirical model of a helical magnetocumulative generator (MCG) has been developed with a single adjustable variable (called the characteristic time) that describes the time dependent changes in the output current of these generators. A brief description of this model and the characteristic time will be presented. This model has been used to analyze several helical MCGs including the Mark IX, Flexy-I, EF-3, Ranchito, and Jemez generators and it was found that there is relative good agreement between the calculated and experimental data. Due to its simplicity, speed, and the fact that it appears to be independent of the type of helical generator being modeled and the nature of the load, this model can serve as an initial design code.
Modular Synthesis of the Pentacyclic Core of Batrachotoxin and Select Batrachotoxin Analogue Designs

Pentacyclic analogues of the potent voltage-gated sodium ion channel agonist batrachotoxin can be accessed through an intermediate furan by exploiting Diels–Alder cycloaddition reactions with ring-strained dienophiles. The use of 3-bromofuran as a 1,2-dianion equivalent, the application of carbamate reductive N-alkylation for homomorpholine ring assembly, and the demonstration of CsF as an effective reagent for generating benzyne, cyclohexyne, and related dienophiles underscore this work.
Temperature‐induced changes in the locomotor capacity of juveniles of Marenzelleria viridis (Polychaeta, Spionidae)

. Populations of Marenzelleria viridis in the Chester River (Kent County, Maryland) experience temperatures ranging from over 30°C in summer to near freezing in winter. Interestingly, M. viridis swims actively in winter. This observation led us to examine the relationship between locomotor capacity and temperature in individuals of M. viridis. Juvenile specimens were collected in February (“cold animals”) and June (“warm animals”). Video analysis revealed that swimming is achieved by flexing the body in cyclic, helical waves. Wave frequencies were measured as an index of locomotor capacity at 5°C, 15°C, and 25°C. The mean wave frequencies of cold animals were 5.4 Hz at 5°C and 7.1 Hz at 15°C (Q10= 1.3); the mean wave frequencies of warm animals were 6.1 Hz at 15°C and 7.8 Hz at 25°C (Q10= 1.3). The effects of changes in water viscosity on wave frequency between 5–25°C were not significant. These results demonstrate that the temperature sensitivity of locomotor capacity in juvenile M. viridis is quite low. We conclude that low temperature sensitivity enables M. viridis to be active throughout the year.
Transforming the sensing and numerical prediction of high-impact local weather through dynamic adaptation

Mesoscale weather, such as convective systems, intense local rainfall resulting in flash floods and lake effect snows, frequently is characterized by unpredictable rapid onset and evolution, heterogeneity and spatial and temporal intermittency. Ironically, most of the technologies used to observe the atmosphere, predict its evolution and compute, transmit or store information about it, operate in a static pre-scheduled framework that is fundamentally inconsistent with, and does not accommodate, the dynamic behaviour of mesoscale weather. As a result, today’s weather technology is highly constrained and far from optimal when applied to any particular situation. This paper describes a new cyberinfrastructure framework, in which remote and in situ atmospheric sensors, data acquisition and storage systems, assimilation and prediction codes, data mining and visualization engines, and the information technology frameworks within which they operate, can change configuration automatically, in response to evolving weather. Such dynamic adaptation is designed to allow system components to achieve greater overall effectiveness, relative to their static counterparts, for any given situation. The associated service-oriented architecture, known as Linked Environments for Atmospheric Discovery (LEAD), makes advanced meteorological and cyber tools as easy to use as ordering a book on the web. LEAD has been applied in a variety of settings, including experimental forecasting by the US National Weather Service, and allows users to focus much more attention on the problem at hand and less on the nuances of data formats, communication protocols and job execution environments.
Actinomycete antibiotics. III. The biogenesis of erythronolide, the C-21 branched chain lactone in erythromycin.

Erythronolide, the macrocyclic lactone which is the aglycon of the complex antibiotic erythromycin (Fig. l), represents a perfect example of a branched chain lipid entirely made up of repeating 3 carbon subunits (2). Although, quantitatively, branched chain fatty acids are not important lipid constituents, ~.~g.~a~e-~el~-rttecte~i~--v~~~in~n~~nn~s-in--~-wid~-vasiety. of natural products. Methymycin (3), neomethymycin (4), oleandomycin (5), pikromycin (6, 7), and other antibiotics of the macrolide group contain aglycons which are partially branched lactones similar to erythronolide. Mycolipenic and mycoceranic acids, present in large amounts in the lipids of tubercule bacilli (8, 9), are partially branched fatty acids again with the same type of repeating 3 carbon subunit. Other substances which may be considered to have at least one 3 carbon subunit are odd numbered straight chain fatty acids and a wide variety of fatty acids and other substances found to have one or more C-methyl group (cf. 10). Robinson has proposed that 3 carbon subunits like those in mycolipenic and mycoceranic acids could arise from propionate or its “biological equivalent” (11). Evidence exists which indicates that this concept may be true for some of the simpler fatty acids which contain 3 carbon units. For instance, n-valeric acid formed in the sheep rumen (12) or by Clostridium kluyveti (13) seems to be derived from propionate and acetate as does the @hydroxyvaleric acid produced by mouse liver slices (14). The perfused cow udder also incorporates propionate-l-Cl* extensively into the odd numbered and branched fatty acids of the milk fats (15). Of more relevance to the 3 carbon units in erythronolide is the recent observation that a-methylbutyric acid, formed by isolated muscle of Ascwis lumbricoides, is made from acetate and propionate with the branch methyl group arising from C-3 of the propionate and the carboxyl group coming from C-l (16).
A Review of the SCD-HEFT, COMPANION, and CARE-HF Trials

The past 10 years have provided a series of well-designed clinical trials to study the effect of the implantable cardioverter defibrillator (ICD) in patients at high risk of sudden death. These studies have been carried out on both sides of the Atlantic. Patient populations have been recruited both from post-event populations and from pre-event populations judged to be at high enough risk to warrant prophylactic ICD implantation. The results of both categories of trial have been remarkably similar. Interestingly, the primary prevention studies were both initiated first and have shown more positive impact of ICD implantation on survival than the secondary prevention trials.
Topical overview of soft-switching PWM high frequency converters

A topical overview of the field of soft-switching PWM DC-DC converters is presented. Over sixty papers published in the 1993-4 have been reviewed and categorized according to the various resonant techniques, control schemes, application requirements or devices used. Also covered are the zero-current and zero-voltage-transition techniques which are at the forefront of research.
A novel low-cost beam-steering technique based on the extended-resonance power-dividing method

A novel phased array based on the extended-resonance power-dividing method has been presented. This method eliminates the need for separate power splitter and phase shifters in a conventional phased-array system, resulting in a substantial reduction in circuit complexity and cost. As a proof of principle, a 2-GHz extended-resonance-based phased array using varactor diodes and microstrip patch antennas has been designed, fabricated, and tested. The measured scan range is 20/spl deg/ and the measured efficiency of the extended-resonance phased-array feed is typically 80%, which corresponds to 1 dB of insertion loss.
Curriculum evaluation. Using National League for Nursing accrediting commission standards and criteria.

Abstract Systematic curricular evaluation is essential to assure integrity of nursing programs. A holistic approach to evaluation using the National League for Nursing Accrediting Commission (NLNAC) Standards and Criteria provides a comprehensive perspective for nursing faculty and administrators. A conceptual framework illustrating the dynamic relationship of curricular context, content, and conduct is presented. This framework suggests that curricular content cannot be isolated and must be examined in light of the milieu or context of curricular delivery as well as the implementation or conduct of curricula. Results of this approach are shared along with recommendations for future use.
Impaired Processing of Complex Auditory Stimuli in Rats with Induced Cerebrocortical Microgyria: An Animal Model of Developmental Language Disabilities

Individuals with developmental language disabilities, including developmental dyslexia and specific language impairment (SLI), exhibit impairments in processing rapidly presented auditory stimuli. It has been hypothesized that these deficits are associated with concurrent deficits in speech perception and, in turn, impaired language development. Additionally, postmortem analyses of human dyslexic brains have revealed the presence of focal neocortical malformations such as cerebrocortical microgyria. In an initial study bridging these research domains, we found that male rats with induced microgyria were impaired in discriminating rapidly presented auditory stimuli. In order to further assess this anatomical– behavioral association, we designed two experiments using auditory-reflex modification. These studies were intended to assess whether auditory processing deficits in microgyric male rats would be seen in threshold detection of a silent gap in white noise, and in oddball detection of a two-tone stimulus of variable duration. Results showed no differences between sham and microgyric subjects on gap detection, but did show that microgyric subjects were impaired in the discrimination of two-tone stimuli presented in an oddball paradigm. This impairment was evident for stimuli with total duration of 64 msec or less, while both groups were able to discriminate stimuli with duration of 89 msec or greater. The current results further support the relationship between malformations of the cerebral cortex and deficits in rapid auditory processing. They also suggest that the parameters characterizing rapid auditory processing deficits for a specific task may be influenced by stimulus features and/or cognitive demand of that particular task.
Structural controls of Holocene reactivation of the Meers fault, southwestern Oklahoma, from magnetic studies

Holocene reactivation of the aseismic Meers fault in southwestern Oklahoma illustrates the limitation of using the historical seismic record for identifying hazardous faults in the central United States. The 26- to 37-km-long fault scarp is one of the few known scamps recording Holocene movement in the central and eastern United States. Two documented late Holocene slip events, each with about 2.5 m of net slip and estimated M s ranging from 6¾ to 7¼, identify the Meers fault as a potentially hazardous fault. During Carboniferous and Early Permian tectonism, the Meers fault displaced rocks of sharply contrasting magnetic properties. Analysis of aeromagnetic data and twelve ground-magnetic profiles provides a detailed look at the fault within the magnetic basement. Because subsequent reactivation has been minor and of an opposite sense, the pronounced magnetic anomaly associated with the Meers fault reflects Paleozoic structures in the magnetic basement. The location of the Holocene fault scarp corresponds to the strong horizontal magnetic gradient caused by Paleozoic offset of magnetic basement, indicating that the Paleozoic fault controlled Holocene displacement. Two features apparent in both sets of magnetic data are splays of the Meers fault northwest of the Holocene scarp and dikelike bodies immediately south of the fault. Magnetic susceptibility measurements and rock magnetic data from unoriented core penetrating a dikelike body were incorporated into models of the ground-magnetic profiles. In most cases, secondary faults mapped or visible on low-sun-angle photographs correspond to faults modeled from magnetic data. This correlation shows that preexisting structures probably controlled secondary faulting. However, secondary faults at the southeastern end of the 26-km long continuous fault scarp, previously interpreted from low-sun-angle photography, are not apparent in the magnetic data. Of importance to seismic hazard evaluation, the magnetic models show that the northwestern splays probably begin at the northwestern end of the reactivated segment and may indicate a persistent rupture propagation barrier to the west. In addition, the models show the dip of the Meers fault to be nearly vertical to about 0.5 km depth. This dip is consistent with the nearly straight fault trace, results of trenching studies, interpretation of shallow seismicreflection data, and regional gravity and aeromagnetic models. In the present-day strike-slip regional stress field, the observed up-to-the-north Holocene displacement suggests that either the fault continues to dip steeply at depth or the regional stress field is approaching a normal-faulting stress regime. If the former is true, the scarcity of near-vertical faults with similar orientation within the area of the southern Oklahoma aulacogen implies that few are likely candidates for reactivation.
On the Continuance of an Analytical Solution across the Elastic-Plastic Boundary of a Mode I Fracture Mechanics Problem

This chapter describes the continuance of an analytical solution across the elastic-plastic boundary of a mode I fracture mechanics problem. The numerical studies for mode I problems involving the Mises yield condition have shown boundaries that differ in shape from loci determined from linear elastic fracture mechanics in general. In this study, the mode I small-scale yielding stresses are substituted into the Tresca yield condition to obtain a prescribed elastoplastic boundary. The plastic stress field that is determined from this function exhibits a discontinuity in the trailing portion of the plastic zone. Physical implications of this solution together with possible applications are discussed. A method of finding an integral surface of a first-order, nonlinear partial differential equation that circumscribes a given surface is presented. It is found that for a particular initial value problem the stresses are uniquely determined on a given boundary. It has been observed that the plastic stress field is unique and continuous across the elastoplastic boundary for prescribed tractions. The strain rates for plane stress under the Tresca yield condition are also elaborated.
Congenital Absence of the Left Atrial Appendage

A 73-year-old woman with no history of cardiac surgery presented with symptomatic atrial fibrillation. A transesophageal echocardiogram was scheduled to exclude thrombus before cardioversion. No obvious intracardiac thrombus was identified, but the patient could not be cleared for cardioversion because the left atrial appendage (LAA) had not been visualized, raising concerns for either a flush occlusion with thrombus or a small ectopic appendage (Figure 1 and online-only Data Supplement Videos I-IV). Contrast-enhanced multidetector computed tomography revealed moderate biatrial enlargement without intracardiac thrombus and confirmed a diagnosis of …
Bulk-skin temperature difference over the tropical Pacific

Sea surface temperatures (SSTs) are necessary for the computation of fluxes of the sensible and latent heat and upward longwave radiation at the air-sea interface. The term SST has usually referred to the sea surface bulk temperature measured by ships or buoys at a depth of a few centimeters to a few meters, rather than the sea surface skin (or radiometric) temperature. Various approaches have been developed in the past several decades to understand the difference between bulk and skin temperatures. However, these methods require the net surface heat flux and near-surface wind speed. This paper develops an algorithm for the computation of skin temperature that uses bulk temperature and wind speed alone, which is then used to produce a multi-year hourly skin temperature dataset using bulk temperature and wind speed data over the tropical Pacific Ocean from the TOGA Tropical Atmosphere-Ocean (TAO) moored buoys.
Image-Rotating Device for a Spectrograph Illumination System

Often, in the course of optical investigations, particularly with spectrographs, it becomes desirable to orient the image of a fixed light source in some particular direction with respect to the spectrograph slit.1 This situation presents no problem if the light path has a section where the light beam is parallel. Here one may use a Dove prism for the image rotation. However, if the light beam has no section with parallel light or if the optical investigations are being carried out in the ultraviolet or infrared regions of the spectrum where the cost of achromatic optics becomes prohibitive, then one must use front-surface mirrors.
The Bartonella henselae sucB gene encodes a dihydrolipoamide succinyltransferase protein reactive with sera from patients with cat-scratch disease

Bartonella henselae is a recently recognized pathogenic bacterium associated with cat-scratch disease, bacillary angiomatosis and bacillary peliosis. A recombinant clone expressing an immunoreactive antigen of B. henselae was isolated by screening a genomic DNA cosmid library by Western blotting with sera pooled from patients positive for B. henselae IgG antibodies by indirect immunofluorescence (IFA). The deduced amino acid sequence of the 43.7 kDa encoded protein was found to be 76.3 % identical to the dihydrolipoamide succinyltransferase enzyme (SucB) of Brucella melitensis. SucB has been shown to be an immunogenic protein during infections by Brucella melitensis, Coxiella burnetii and Bartonella vinsonii. The agreement between reactivity with a recombinant SucB fusion protein on immunoblot analysis and the results obtained by IFA was 55 % for IFA-positive sera and 88 % for IFA-negative sera. Cross-reactivity was observed with sera from patients with antibodies against Brucella melitensis, Mycoplasma pneumoniae, Francisella tularensis, Coxiella burnetii and Rickettsia typhi.
Dissection of 16S rRNA Methyltransferase (KsgA) Function in Escherichia coli

A 16S rRNA methyltransferase, KsgA, identified originally in Escherichia coli is highly conserved in all living cells, from bacteria to humans. KsgA orthologs in eukaryotes possess functions in addition to their rRNA methyltransferase activity. E. coli Era is an essential GTP-binding protein. We recently observed that KsgA functions as a multicopy suppressor for the cold-sensitive cell growth of an era mutant [Era(E200K)] strain (Q. Lu and M. Inouye, J. Bacteriol. 180:5243-5246, 1998). Here we observed that although KsgA(E43A), KsgA(G47A), and KsgA(E66A) mutations located in the S-adenosylmethionine-binding motifs severely reduced its methyltransferase activity, these mutations retained the ability to suppress the growth defect of the Era(E200K) strain at a low temperature. On the other hand, a KsgA(R248A) mutation at the C-terminal domain that does not affect the methyltransferase activity failed to suppress the growth defect. Surprisingly, E. coli cells overexpressing wild-type KsgA, but not KsgA(R248A), were found to be highly sensitive to acetate even at neutral pH. Such growth inhibition also was observed in the presence of other weak organic acids, such as propionate and benzoate. These chemicals are known to be highly toxic at acidic pH by lowering the intracellular pH. We found that KsgA-induced cells had increased sensitivity to extreme acid conditions (pH 3.0) compared to that of noninduced cells. These results suggest that E. coli KsgA, in addition to its methyltransferase activity, has another unidentified function that plays a role in the suppression of the cold-sensitive phenotype of the Era(E200K) strain and that the additional function may be involved in the acid shock response. We discuss a possible mechanism of the KsgA-induced acid-sensitive phenotype.
Effects of geometric joint constraints on the selection of final arm posture during reaching: a simulation study.

Significant debate exists regarding the neural strategies underlying the positioning and orienting of the hand during voluntary reaching movements of the human upper extremity. Some authors have suggested that positioning and orienting are controlled independently, while others have argued that a strong interdependence exists. In an effort to address this uncertainty, our study employed computer simulations to examine the impact of physiological limitations of joint rotation on the proposed independence of hand position and orientation. Specifically, we analyzed the effects of geometric constraints on final arm postures using a 7 degree-of-freedom model of the human arm. For 20 different hand configurations within the attainable workspace, we computed sets of achievable joint angles by applying inverse kinematics. From each set, we then calculated the locus of possible elbow positions for the particular final hand posture. When the joints were allowed 360° of rotation, the loci formed complete circles; however, when joint ranges were limited to physiological values, the extent of the loci decreased to an average arc angle of 54.6° (±27.9°). Imposition of joint limits also led to practically linear relationships between joint angles within a solution set. These theoretical results suggest a requirement for coordinated interaction between control of the joints associated with hand position and those involved with hand orientation in order to ensure attainable joint trajectories. Furthermore, it is conceivable that some of the correlations observed between joint angles in the course of natural reaching movements result from geometric constraints.
Multi-level approach for integrated spiral inductor optimization

The efficient optimization of integrated spiral inductors remains a fundamental barrier to the realization of effective analog and mixed-signal design automation. In this paper, we develop a scalable multi-level optimization methodology for spiral inductors that integrates the flexibility of constrained global optimization using mesh-adaptive direct search (MADS) algorithms with the rapid convergence of local nonlinear convex optimization techniques. Experimental results indicate that our methodology locates optimal spiral inductor geometries with significantly fewer function evaluations than current techniques.
Size- and Age-dependent Variation in the Properties of Sap- and Heartwood in Black Locust (Robinia pseudoacacia L.)

Dissection and mechanical bending experiments showed that the cross-sectional area and elastic moduli of sap- and heartwood varied within the trunk and branches as a function of the distance from the top of a 43-year-old black locust tree (Robinia pseudoacaciaL.). Wood in branches less than 1 m from the top of the tree consisted entirely of sapwood; the majority of the wood from more basipetal (and older) parts of the tree was heartwood. The Young's elastic moduli of sap- and heartwood increased towards the base of the trunk, and, on average, the modulus of the sapwood was 35%less than that of the heartwood. Younger, more distal tree limbs, therefore, were more flexible than older portions of the same tree. Simple bending experiments showed that the flexural rigidity of young limbs was governed by the location, physical properties, and the relative quantities of the two types of wood. The rigidity of limbs increased toward the base of the tree, and was dominated by sapwood in young limbs and by heartwood in the oldest parts of the tree. These trends predict that the younger, distal limbs of this tree can more easily deflect and bend in the wind, thereby reducing drag and the total bending moment on the tree trunk, while older limbs and the trunk are sufficiently rigid to support static self-loadings. Further study, however, is required to determine whether the trends reported here apply to all trees of this species and to trees of different species.
Transfer-function models for a new class of physically-realizable inverse-systems for linear dynamical systems

The author previously (1994) presented a new alternative formulation of, and solution to, the inverse-system realization problem, based on "disturbance-observer" techniques of disturbance-accommodating control theory (DAC). In the present paper that inverse-system realization methodology is used to develop explicit, physically-realizable, guaranteed stable transfer-function models for generic families of inverse-systems S/sup -1/ corresponding to families of given (linear, time-invariant) systems S described also by transfer-function models.
Whitecaps and Foam

Whitecaps are the transient manifestations of the sub-surface bubble plumes formed when a wave breaks on the ocean surface. The frequency of whitecap formation is a function of the wind speed over the sea, and to a lesser degree, of other meteorological and oceanographic variables. Foam patches are more persistent features that result because of the stabilization of bubbles by organic surfactants. When whitecap bubbles burst at the sea surface they inject into the atmosphere sea spray, and by a variety of mechanisms bubbles contribute to the air-sea exchange of moisture, heat, and gases.
The Evolution of the Treaty-Making Power in the Commonwealth of Australia

“Canada has very few statutory provisions relating to the exercise of the treaty-making power. The rules followed, so far as they can be ascertained, are for the most part founded on unwritten custom.”1 Professor Deener points out that this “statement serves to underline the importance of broad principle and historical precedent in the evolution of Canada’s treaty power.” 2 The statement also reflects to a considerable degree the Australian process of treaty-making. In a statement by the Australian Commonwealth Government, it was said “that the power to make treaties in Australia is... at common law and without statutory provision.” 3 Indeed, “the general law of the Commonwealth is not ordinary law. It lies rather on the periphery of municipal law, where it marches with politics, with constitutional convention and with international law.” 4 Both Canada and Australia are the product of a federalizing movement of former British colonies in the nineteenth century. The Federal Commonwealth of Australia came into existence in January 1901 as a federation of the following former British colonies: New South Wales, Victoria, South Australia, Tasmania and (by a somewhat different process) Western Australia. Origin and development of the treaty-making power in the Commonwealth of Australia must be considered in the light of constitutional and historical changes undergone in the Commonwealth of Australia both before and since federation.
The Endorsement Factor

During the 1980s, the Supreme Court decided two important cases addressing the constitutionality of local government displays of creches, or nativity displays, a mere five years apart. The Court held in Lynch v. Donnelly that a creche located within a display of a variety of Christmas symbols, including, “a Santa Claus house, reindeer pulling Santa’s sleigh, candy-striped poles, a Christmas tree, carolers, cutout figures representing such characters as a clown, an elephant, and a teddy bear, hundreds of colored lights,” and a, “Season’s Greetings,” banner was not a violation of the Establishment Clause and thus constitutional. The case, however, did not finally determine the constitutionality of creche displays because the Court treated the issue as heavily fact-dependent. Five years later, in County of Allegheny v. ACLU, the Supreme Court held the display of a creche situated on the courthouse’s interior steps did violate the Establishment Clause.
Postoperative Care Following Surgery for Posterior Fossa Tumors

As immediate postoperative period is considered the time from recovery of anesthesia to discharge from the hospital, usually from 1 to 4 weeks, although in some countries (e.g., the United Kingdom), legally the postoperative period extends to the first 4 weeks from operation, and every complication in that period is considered a result of, or intimately related to, the operation, regardless of whether the patient has gone home. Posterior fossa surgery poses many dangers and the postoperative period requires particular vigilance.