cssi/SciSciGPT-SciSciNet huggingface dataset:
Myopotential Inhibition of Unipolar Lithium Pacemakerss

The effect of Isometric upper extremity exercise on pacemaker function was evaluated in 27 patients who remained pacemaker-dependent during testing. Inhibition was demonstrated in eight (31 percent) of which five were symptomatic. Based on design of the sensing amplifier and return to an all-metal housing in the unipolar lithium pulse generators, myopotential inhibition is being recognized as one cause of symptomatic pacemaker inhibition that is more common than generally appreciated. A method of evaluation and management options for symptomatic patients are discussed. Routine testing of all patients should be performed at the time of a regular office evaluation. If one model pulse generator appears to be particularly prone to myopotential inhibition, this knowledge should be considered in the choice of future pacing systems.
The development of mutual funds around the world

Abstract With few exceptions, mainly in Asia, mutual funds grew explosively in most countries around the world during the 1990s. Equity funds predominate in Anglo-American countries and bond funds in most of Continental Europe and in middle-income countries. Capital market development (reflecting investor confidence in market integrity, liquidity and efficiency) and financial system orientation are found to be the main determinants of mutual fund development. Restrictions on competing products may have acted as a catalyst for the development of money market and (short-term) bond funds.
The Effect of Lateral Rod Displacement on Laminar-Flow Transfer

Heat transfer in longitudinal laminar flow through tightly packed rod bundles is analyzed for a rod displaced from its symmetrical position. The influences of the P/D ratio, the magnitude of σ, and the type of thermal boundary condition, etc. on the variation of the coolant temperature field and the rod-average Nusselt number are investigated. Average Nusselt numbers for the displaced rod are calculated for rod bundles with 1.00 ≤ P/D ≤ 2.0 and 0 ≤ σ ≤ 0.8. The results for the special case of σ = 0 (i.e., for symmetrical rod bundle) show excellent agreement with those reported by Dwyer and Berry [1], who analyzed numerically the corresponding problem for symmetrical rod bundles.
Glycolide copolymer staple-line reinforcement reduces staple site bleeding during laparoscopic gastric bypass: a prospective randomized trial.

Hypothesis The use of staple-line reinforcement sleeves during laparoscopic gastric bypass reduces staple-line bleeding, which may translate into a reduction in the rate of gastrointestinal hemorrhage. Design Prospective randomized trial. Setting University hospital Patients and Interventions Thirty-four patients undergoing laparoscopic gastric bypass were randomly assigned to receive either no reinforcement (control group, n = 17) or reinforcement of the staple line with glycolic copolymer sleeves (treatment group, n = 17). Main Outcome Measures Demographic data, the number of stapler loads used, the number of staple-line bleeding sites, the amount of blood loss, the length of time required to obtain hemostasis of the staple lines, operative time, intraoperative and postoperative complications, and serial hemoglobin levels. Results The mean number of stapler loads used was similar between groups. The mean number of staple-line bleeding sites was significantly fewer in the treatment group for division of gastric tissue (0.4 vs 2.5 bleeding sites), jejunal tissue (0.1 vs 0.6 bleeding site), and mesenteric tissue (0 vs 0.8 bleeding site). The mean blood loss was lower in the treatment group (84 vs 129 mL). Staple misfire occurred in 1 (0.7%) of 143 stapler loads used in the treatment group compared with 0 (0%) of 138 stapler loads used in the control group. The time to obtain staple-line hemostasis was shorter in the treatment group (1.2 vs 10.1 minutes). The total operative time was similar between groups. There was no mortality or postoperative leaks. One patient in the control group had postoperative gastrointestinal hemorrhage requiring blood transfusion and reoperation. There was no significant difference in the mean hemoglobin level between groups on the first postoperative day. Conclusions The use of glycolide copolymer staple-line reinforcement sleeves in patients undergoing laparoscopic gastric bypass is safe and significantly reduces staple-line bleeding sites and may reduce the incidence of gastrointestinal hemorrhage.
Recurrent and persistent otitis media

Recurrent acute otitis media occurs during the first several years of life in approximately 20 to 30% of the pediatric population. A clinical challenge closely related to recurrent otitis media is persistent otitis media, manifested by persistence during antimicrobial therapy of symptoms and signs of middle ear infection (treatment failure) and/or relapse of acute otitis media within 1 month of completion of antibiotic therapy. Recurrent and persistent otitis media infections are early childhood problems with identifiable risk factors. Differentiation of these infections from otitis media with effusion is important in avoiding misdiagnosis and overtreatment with antibiotics. The predominant pathogens of recurrent and persistent acute otitis media are antibiotic-resistant Streptococcus pneumoniae and beta-lactamase-producing Haemophilus influenzae. A working group convened by the Centers for Disease Control recommended three antibiotics for the treatment of recurrent and persistent acute otitis media: (1) amoxicillin/clavulanate in combination with amoxicillin (high dose amoxicillin regimen, 80 to 90 mg/kg/day); (2) cefuroxime axetil (standard dose, 30 mg/kg/day); and (3) ceftriaxone (possibly requiring up to three injections to optimize clinical success). Other antibiotics were considered suboptimal or had accumulated insufficient data upon which to base a judgment. Conclusions. Optimal management of recurrent and persistent acute otitis media is a clinical challenge. Accurate diagnosis of acute otitis media is the first step in optimal management. Selection of appropriate antibiotic therapy should take into account the major pathogens (S. pneumoniae, H. influenzae and Moraxella catarrhalis) and the occurrence of antibiotic resistance.
The Effect of Prenatal Natural Disaster Exposure on School Outcomes

This study looks at the impact of exposure to natural disasters during pregnancy on the educational outcomes of North Carolina children at the third grade level. A broad literature relates negative birth outcomes to poor educational performance, and a number of recent studies have examined the effect of prenatal exposure to natural disasters on birth outcomes. This study takes the next step by considering how prenatal exposure affects later outcomes. Combining North Carolina administrative data on births and school performance with disaster declarations from the U.S. Federal Emergency Management Agency (FEMA) allows for the identification of children who were exposed to disasters during prenatal development. These children are compared with other children born in the same county who were not exposed to disasters while in utero. Regression results suggest that children exposed to hurricanes prenatally have lower scores on third grade standardized tests in math and reading. Those exposed to flooding or tornadoes also have somewhat lower math scores. Additionally, results suggest that these negative effects are more concentrated among children in disadvantaged subgroups, especially children born to black mothers. However, no evidence exists that these effects are mediated by common measures of birth outcomes, including birth weight and gestational age.
Toward automated exploration of interactive systems

The ease with which a user interface can be navigated strongly contributes to its usability. In this paper we describe preliminary results of a project aimed at making the evaluation of user interfaces from this perspective more routine. We have designed a system to carry out an autonomous, exploratory navigation through the graphical user interface of interactive, off-the-shelf software applications. The system is not a robust tool, but rather a proof of concept that can exhibit interesting behaviors. The traversal process generates a representation of the connectivity of the user interface, as well as navigational paths to specific commands. The reasoning component of the system is based on the ACT-R architecture, while the perceptual and motor components of the system are built on top of the SegMan perception/action substrate. We present the design of the system and its use in exploring a simple user interface.
Pushing boundaries of normalcy: employing critical disability studies in analyzing medical advocacy websites

We are all patients in some way---or, at the least, patients-in-waiting. Although I am reminded of this reality on a daily, if not hourly, basis, it is most apparent when I log onto the Internet to engage in what millions of users have begun doing in the last few decades: surf for health information. Typing in "breast cancer" for what must be the thousandth time, I look again for research that will provide insight into this biopolitical phenomenon. Perhaps more telling, I search for information about my own body. As I scan the material, I cannot help but ask myself what qualities I possess or have developed and how they fit into the categories of "high risk," "moderate risk," or "low to no risk."
Multinationals, Geographical Spillovers, and Regional Development in Thailand

Sajarattanochote S. and Poon J. P. H. Multinationals, geographical spillovers, and regional development in Thailand, Regional Studies. Much of the evidence supporting the competency of agglomeration economies through regional spillovers is largely derived from industrialized countries. This literature focuses on the advantages of geographical clustering for firms' technological innovation. Their findings, however, are less relevant for a developing country like Thailand where human capital and technological capability is low. This paper examines the geography of technology flows among multinational enterprises located in the metropolitan region of Bangkok (BMA). It finds evidence of limited regional spillovers to first- and second-order neighbours. Transfer of technology to Thai firms further varies by nationality, sector, size, and age of multinational enterprises. Sajarattanochote S. et Poon J. P. H. Les societes multinationales, les retombees geographiques et l'amenagement du territoire en Thailande, R...
Regeneration of the photoprotein aequorin.

THE photoprotein aequorin (molecular weight about 30,000) isolated from the bioluminescent jellyfish Aequorea aequorea1–3 emits blue light (λm a x 470 nm)4 by an intramolecular reaction in aqueous solution when Ca2+ is added, in the presence or absence of molecular oxygen1. This reaction has been postulated5 to follow the scheme in (Fig. 1), in which an essential component H2O2 of aequorin is bound to the protein part in a form such as a peroxyacid or an α-hydroxyhydroperoxide which readily releases H2O2. Hypothesised roles for peroxide in aequorin (see recent review6) are consistent with this scheme. YC is a yellow chromophore of unknown structure, responsible for the colour of aequorin from which it has been isolated5, and found to be different from other components in Fig. 1.
Electrophysiological properties of spinally-projecting A5 noradrenergic neurons

Abstract Spinally-projecting A5 neurons were studied with anatomical and electrophysiological techniques in the rat. A detailed study of the number and distribution of spinally-projecting catecholaminergic (CA) and non-catecholaminergic neurons present in a defined area of ventrolateral pontine reticular formation was performed using a sequential technique for the detection of CA fluorescence and retrogradely transported HRP. Using control animals and rats with 6-hydroxydopamine-induced lesions of spinal CA axons, it was concluded that up to 93% of all noradrenergic (NE) neurons present in the area investigated send an axonal process to the thoracic spinal cord and that NE neurons constitute at least 90% of all spinally-projecting neurons present in the same area. Single unit recordings of spinally-projecting neurons were obtained in the same area of the reticular formation in urethane-anesthetized, paralyzed and respirated rats. Based on the above-mentioned anatomical data, antidromic activation from thoracic spinal cord provided a necessary and sufficient criterion for the identification of A5 NE cells. These neurons had a conduction velocity of 2.5 m/s, a discharge rate of up to 4 spikes/s and all were inhibited by i.v. clonidine or des-methylimipramine (DMI). The inhibition produced by the latter drugs was always reversed by the α-2 adrenergic antagonists piperoxan or yohimbine. Antidromic (AD)-activation was followed by a period of inhibition whose duration was increased by raising the intensity of the stimulus or by administration of the NE-uptake inhibitor DMI. The effect of the latter was reversed by administration of the α-2 antagonist piperoxan.
Nicotine and Lipopolysaccharide Affect Cytokine Expression From Gingival Fibroblasts

Background: This in vitro study investigated the influence of nicotine, lipopolysaccharide (LPS), and a combination of both agents on cytokine expression from human gingival fibroblasts (HGFs).Methods: HGFs were exposed for 48 hours to 250 μg/ml nicotine, 1 μg/ml Porphyromonas gingivalis LPS, or both. The expression of multiple cytokines was detected in the HGFs conditioned media using cytokine protein arrays.Results: The untreated HGFs expressed several cytokines, which included relatively high levels of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1). They also expressed low levels of growth-regulated oncogene (GRO), IL-3, and IL-10. Nicotine had the greatest effect on the expression of GRO-α, IL-7, IL-10, and IL-15 compared to the untreated control. P. gingivalis LPS had the greatest effect on the expression of GRO-α; IL-7; IL-10; and RANTES (regulated on activation, normal T-cell expressed, and presumably secreted) compared to the untreated control. The combination of both age...
An exercise test for coronary insufficiency.

Any exercise tolerance test is intended to record the objective accompaniments of coronary insufficiency. The test must therefore be stressful to effect such insufficiency. Described in this report is an exercise test which is considered specific in demonstrating coronary inadequacy when present, and reliable in ruling it out, provided that the effects of tachycardia on the electrocardiogram are recognized.
Rapid detection methods for bacteriol identification in urologic office laboratory

Abstract A regulatory era is taking shape under the Health Care Financeing Administration (HCFA) which eventually will be implemented under the Clinical Laboratory Improvement Amendments of 1988 (CLIA '88). Sweeping changes are planned for all alaboratories, including physician's office and group practice offices. Both of these groups have previously been exempt from federal controls. Though many urologists have been doing uring cultures and colony counts in their offices for a long time, it is important that precise bacterial identification also be done for good patient care, to control quality and cost, and for more rapid results. Herein, we review many commercial kits now available for precise bacterial identification in the office laboratory. These are largely unknown to most practicing ueologists but have been available to microbiologists They easily can be learned and used in an ofice or group practice laboratory. Urologists are competent to perform these tests, especially with a review course or with assistance from thei local hospital microbiology laboratory
Endoscopic variceal ligation is superior to combined ligation and sclerotherapy for esophageal varices: A multicenter prospective randomized trial

Patients who have bled from varices remain at risk for rebleeding. There is interest in methods that would enable rapid eradication of varices. The present trial was designed to study whether combining ligation with sclerotherapy will allow quicker eradication of varices than either modality alone. Patients with bleeding esophageal varices were randomized into ligation or combination therapy groups. Patients in the ligation group were treated with endoscopic rubber band ligation alone. In combination group patients, each variceal column was ligated distally and 1 mL of ethanolamine was injected proximal to each ligated site. Subsequent treatment sessions were at 7- to 14-day intervals until varices were eradicated. The clinical and endoscopic characteristics of 25 patients in the ligation group were similar to those of 22 patients in the combination group. Follow-up was up to 30 months. Active bleeding was controlled in 100% of patients in the ligation group and 75% of those in combination group (P = NS). It took 3.3 +/- .4 (range, 1-7) sessions to eradicate varices with ligation and 4.1 +/- .6 (1-7) with combination therapy (P = NS). Survival (four deaths in ligation group, 8 in combination group), rebleeding rate (25% vs. 36%), and varix recurrence (16% vs. 23%) also were similar. There were more complications with combination therapy, including deep ulcers (65% vs. 20%; P < .05); dysphagia (30% vs. 0%; P < .05), with three strictures requiring dilation; and pain (30% vs. 10%; P = NS). Our results show that sclerotherapy combined with ligation offers no benefit over ligation alone. The higher complication rate with combination therapy does not warrant this approach.
AN ALTERNATIVE METHOD FOR A FAST SEPARATION OF PHOSPHOTYROSINE

A simple and rapid procedure is described for fully separating phosphotyrosine from phosphoserine and phosphothreonine through one-dimensional thin-layer chromatography. The migration properties of these phosphoamino acids are compared with those of CMP, UMP, ATP, ribose phosphate, and inorganic orthophosphate, considered the most frequent comigrating products derived from 32P-labeling experiments. We demonstrate that Rf values for the three phosphoamino acids differ from those displayed by the mentioned contaminating compounds. One of the most relevant advantages of this procedure is that a complete separation of phosphotyrosine can be achieved in only 90 min.
EFFECTS OF ACUTE HYPOXIA ON CELLULAR ELECTRICAL PROPERTIES OF THE SINUS NODE (SN) AND ATRIUM

The heart rate and arrhythmogenic effects of acute hypoxia (H) are incompletely understood. Some studies have suggested a differential effect of H dependent upon the extent to which Ca and Na participate in the action potential (AP). We studied the effects of acute, severe H on SN and atrial parameters using rabbit preparations and standard microelectrode techniques. AP from true SN pacemaker cells (dependent on the slow inward Ca current (isi)) were most effected by H. There were significant (p·0.05) decreases in spontaneous rate, AP amplitude (APA), maximum dia stolic potential (MDP) and slope of phase 4 depolarization. Corrected SNRT and SACT were markedly increased. H produced SN entrance block, pacemaker shifts and ectopic activity in many preparations. AP from subsidiary SN cells (a two component AP dependent on Na and Ca) were less effected by H. There were only moderate decreases in APA and MDP. AP from atrial muscle are very dependent on the fast Na current for depolarization. H produced no changes in APA, MDP or Vmax. AP duration (at 50 and 90% repolarization) and atrial effective refractory period were significantly shortened by H. The decrease in AP duration (due to shortening of the plateau) may be related to H induced decreases in the Ca isi. In summary, many of the arrhythmias resulting from clinical H can be explained by the observed changes in cellular electrophysiology. There appears to be a high sensitivity of Ca dependent channels (and AP) to the effects of H.
Some axisymmetric self-similar galaxy models

Distribution functions are presented for some axisymmetric self-similar galaxy models with flat rotation curves. In particular, we record velocity distribution functions for the logarithmic potentials studied by Richstone. These distribution functions depend on two integrals only. Other distribution functions (possibly involving more or other integrals) associated with the same mass model differ only by an additive function that integrates over velocities to yield zero density everywhere. However, a given distribution function can be associated with different mass models.
Existentialist Voluntarism as a Source of Normativity

I defend a neo-Kantian view wherein we are capable of being completely autonomous and impartial and argue that this ability can ground normativity. As this view includes an existentialist conception of the self, I defend radical choice, a primary component of that conception, against arguments many take to be definitive. I call the ability to use radical choice ‘existentialist voluntarism' and bring it into a current debate in normative philosophy, arguing that it allows that we can be distanced from all ends at once so as to be completely impartial. Finally, I indicate how this can be the source of normativity as it provides a purely impartial reason for being rational. Philosophical Papers Vol. 37 (1) 2008: pp. 89-129
Parathyroid Hormone-Related Protein: Primary Osteolytic Factor Produced by Breast Tumor Cells in Vitro?

Tumor cells in bone metastases are thought to induce bone resorption primarily by releasing paracrine factors. Parathyroid hormone related protein (PTHrp) has been proposed to mediate osteolytic activity of many tumors. PTHrp is produced by 40% to 60% of breast tumors and is elevated in the serum of up to 50% of patients with breast cancer metastases to bone. Most biologic processes in humans are heterogeneous in nature, so the purpose of this study was to investigate the hypothesis that paracrine factors other than PTHrp could mediate bone resorption by breast tumor cells. Serum-free conditioned medium (CM) was collected from five human breast tumor cell lines and tested for bone resorption-stimulating activity (BRSA) in mouse calvaria organ cultures. CM from all tumor cells studied produced significant bone resorption, comparable to that produced by 10 nM PTH. Small amounts of immunoreactive PTHrp (1.4–12.5 pM) were produced by all breast tumor cell lines. When tested in vitro, equivalent amounts of human PTHrp[1–36] did not produce significant bone resorption. Indomethacin (1 μM) significantly blocked BRSA by CM from all cell lines but did not decrease BRSA by PTHrp. In contrast PTHrp antibody (130 μg/ml) completely blocked BRSA by 1 nM PTHrp but did not modify BRSA by CM of breast tumor cells. The results of this study support the hypothesis that breast cancer cells release paracrine factors in vitro that stimulate bone resorption by a mechanism that is partially dependent on prostaglandin synthesis and at least in part different from that of PTHrp. These results suggest that breast tumor cells may produce osteolytic factors that are distinct from PTHrp and that may constitute a more significant portion of the osteolytic activity produced at sites of metastasis in bone, although additional in vivo studies are needed to test this hypothesis.
A new theory for free-surface formation in solid continua

Abstract In essence, fracture mechanics consist of the conventional boundary-value problem formulation of continuum mechanics, along with a variety of fracture criteria that govern the advance of crack fronts. The assumption that the material response is governed by a local constitutive model everywhere in the body, even at points that are arbitrarily close to the crack front, generally leads to an unbounded stress field as the crack front is approached. Also, processes such as metal-cutting and penetration share with fracture the essential feature of new-free-surface formation, but do not fit easily within the conventional fracture theory. For these and other reasons, it seems worthwhile to seek a broader theoretical construct which encompasses surface separation in a more general setting. With this motivation, a new theory is proposed which applies generally to surface separation in solid continua, but which nonetheless yields fracture-mechanics-type predictions in appropriate special cases. The proposed exclusion region theory involves identification of a small material neighborhood that contains the separation front. A generalized constitutive description that derives directly from the local constitutive model is constructed for the exclusion region. A separation criterion is formulated with reference to tractions on, and/or distortion of, the exclusion region. The direction-of-advance of the separation front is determined as a natural consequence of the separation criterion. The material parameters appearing in the separation criterion can generally be determined from conventional fracture tests. The theory has been implemented in a finite element code. Two example problems illustrating certain important aspects of the theory are presented.
Extended separation theorem and exact analytical solution of stochastic control

The stochastic optimal control of linear, discrete scalar systems are studied. A method is presented for relaxing the usual assumption that the probability distributions of the disturbances are perfectly known. Two problems are considered here: (1) the problem where the plant noise variance and the measurement noise variance both are unknown but fixed, and it is shown that the well-known separation theorem for the filtering and control still holds; and (2) the problem where the mean and variance of the plant disturbance are unknown but fixed with perfect measurement. The exact analytical solution of the feedback control law is obtained.
Roughness constraints in surface wave tomography

A set of inversion experiments is described that tests the ability of global surface wave tomography to retrieve long-wavelength upper mantle velocity structure in the presence of a modest level of rough structure. We use upper-mantle model M84A, augmented with randomly-generated lateral structure to smax = 20, to calculate coupled-mode synthetic seismograms by means of the subspace projection method. The data kernels for path-integral data observables do not belong to the model space of allowable phase velocity perturbations, suggesting that constraints on model roughness in the inversion should lead to a better agreement with the long-wavelength part of the ‘true‧ model than do the commonly-used constraints on model size. Coherence C between the inverted and the input model is enhanced by using roughness constraints. Estimation of perturbation size is more stable using roughness constraints, but is subject to a positive bias, especially for periods T > 200 s. We can achieve, with a data set of 672 R1 and R2 phase delays, C ≥ 0.9 only for s ≤ 6, suggesting ‘leakage‧ bias caused by the breakdown of the pure-path assumption.
Estimating Expected Returns for Developed Equity Markets

This research examines model construction, performance, and other issues related to estimating expected returns for twenty-one developed country equity markets. Using in- and out-of-sample time periods, the author examines the properties of expected and realized returns. Results show that the country-specific alpha models predicts expected equity returns quite well. The results are stronger in-sample than out-of-sample. Using subsets for the G-7 countries or regional models reduces, but does not eliminate, alpha effectiveness.
Continuous infusion of proinflammatory cytokines into the brain to study brain cytokine induced local and systemic immune effects.

Abstract Proinflammatory cytokines are produced in the brain after various kinds of insult (ischemia, trauma, infection). In this process interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α are most important. These cytokines are key mediators of inflammation. Furthermore, these cytokines can act as neurotransmitters and develop direct effects on the central nervous system (CNS) including fever, sleep and stimulation of the neuroendocrine as well as sympathetic nervous system. Moreover, IL-1β and TNF-α may also be involved in brain repair and regenerating processes. However, most of the data about the role of cytokines in the brain have been obtained from either in vitro studies or bolus injections into the brain parenchyma or cerebroventricular system. On the other hand, it is known that cytokines are released continuously into the brain after a cerebral insult over a period of 24 to 48 h. In order to further complete the knowledge about the interactions between neural and immune cells to overcome the primary insult and initiate repair and regeneration in the CNS, a new animal model of local inflammation reaction was established using chronic intracerebral infusion of rat recombinant cytokines. Themes : Endocrine and autonomic regulation Topics : Neural-immune interactions
Comparison of recent utilization trends in radionuclide myocardial perfusion imaging among radiologists and cardiologists.

Purpose To study recent practice patterns in radionuclide myocardial perfusion imaging (MPI) and related procedures among radiologists, cardiologists, and other physicians. Methods and Materials The nationwide Medicare administrative Part B claims summary databases from 1998 and 2002 were used to assess utilization rate changes in the 4 primary procedure codes for MPI, the seven codes for diagnostic cardiac catheterization with coronary angiography, and the single code for stress echocardiography. Rate changes among radiologists, cardiologists, and other physicians were determined for the total Medicare population, as well as for the 3 primary places of service at which imaging is formed: hospital inpatient facilities, hospital outpatient facilities, and private offices. Ratios of the use of the 2 supplementary codes for left ventricular (LV) wall motion and ejection fraction to that of the primary MPI codes were calculated for 2002. Results The utilization rate per 1000 Medicare beneficiaries of MPI rose among radiologists from 19.8 in 1998 to 20.1 in 2002, a 2% increase. The rate among cardiologists rose from 22.9 in 1998 to 40.7 in 2002, a 78% increase. Most of this growth occurred in cardiologists' offices, where the utilization rate increased 101% over the 4 years. In 2002, the ratios of the use of the supplementary LV wall motion and ejection fraction codes to that of the primary MPI codes were 1.73 for cardiologists and 1.46 among radiologists. Between 1998 and 2002, the utilization of diagnostic cardiac catheterization among cardiologists increased by 19%, and their utilization of stress echocardiography increased by 21%. Conclusion In recent years within the Medicare population, the rate of utilization of MPI among radiologists has remained relatively stable, whereas it has risen sharply among cardiologists. The greatest growth was seen in cardiologists' private offices. This raises concerns about possible inappropriate utilization of MPI and also about the potential effect self-referral has on this utilization trend. The increased use of MPI by cardiologists did not result in reduction in their use of either cardiac catheterization with coronary angiography or stress echocardiography.
Combined thoracic aortic dissection and abdominal aortic fusiform aneurysm

Certain clinical and autopsy findings are described in 13 patients who had both aortic dissection (AD) and fusiform abdominal aortic aneurysm (AAA). All 13 patients had severe and extensive aortic atherosclerosis. The AAA was diagnosed clinically in 9 patients, and 5 had the AAA resected. The AD was diagnosed clinically in 5 patients, and 2 underwent attempted operative repair. Two patients who had the AAA resected because of suspected rupture were found later to have ruptured a more proximal AD. Thus, AD occurs occasionally in patients who have AAA. In older persons with suspected rupture of an AAA, a more proximal rupture of an AD should be ruled out. When both AAA and AD are present in the same patient, the AD is more likely the cause of cardiovascular collapse than is rupture of the AAA.
Finite Element Simulation of Solid Rocket Booster Separation Motors During Motor Firing

One of the toughest challenges facing Solid Rocket Booster (SRB) engineers is to ensure that any design changes made to the Shuttle-Derived Booster Separation Motors (BSM) for future space exploration vehicles is able to withstand the increasingly hostile motor firing environment without cracking its critical component - the graphite throat. This paper presents a critical analysis methodology and techniques for assessing effects of BSM design changes with great accuracy and precision. For current Space Shuttle operation, the motor firing occurs at SRB separation - approximately 125 seconds after Shuttle launch at an altitude of about 28 miles. The motor operation event lasts about two seconds, however, the surface temperature of the graphite throat increases approximately 3400 F in less than one second with a corresponding increase in surface pressure of approximately 2200 pounds per square inch (psi) in less than one-tenth of a second. To capture this process fully and accurately, a two-phase sequentially coupled thermal-mechanical finite element approach was developed. This method allows the time- and location-dependent pressure fields to interact with the spatial-temporal thermal fields throughout the operation. The material properties of graphite throat are orthotropic and temperature-dependent. The analysis involves preload and multiple body contacts.
Association of the Membrane Proximal Regions of the α and β Subunit Cytoplasmic Domains Constrains an Integrin in the Inactive State

Abstract The adhesiveness of integrins is regulated through a process termed “inside-out” signaling. To understand the molecular mechanism of integrin inside-out signaling, we generated K562 stable cell lines that expressed LFA-1 (αLβ2) or Mac-1 (αMβ2) with mutations in the cytoplasmic domain. Complete truncation of the β2 cytoplasmic domain, but not a truncation that retained the membrane proximal eight residues, resulted in constitutive activation of αLβ2 and αMβ2, demonstrating the importance of this membrane proximal region in the regulation of integrin adhesive function. Furthermore, replacement of the αL and β2 cytoplasmic domains with acidic and basic peptides that form an α-helical coiled coil caused inactivation of αLβ2. Association of these artificial cytoplasmic domains was directly demonstrated. By contrast, replacement of the αL and β2 cytoplasmic domains with two basic peptides that do not form an α-helical coiled coil activated αLβ2. Induction of ligand binding by the activating cytoplasmic domain mutations correlated with the induction of activation epitopes in the extracellular domain. Our data demonstrate that cytoplasmic, membrane proximal association between integrin α and β subunits, constrains an integrin in the inactive conformation.
Using Students' Personal Ads to Teach about Interpersonal Attraction and Intimate Relationships

Many students have beliefs about interpersonal relationships that are inconsistent with empirical research. For example, some students report that attractiveness is less important than personality when choosing romantic partners; however, evidence suggests the opposite (Sprecher & Regan, 2002). Our activity in which students wrote personal ads and anonymously exchanged them examined and challenged students' relationship beliefs. Students read ads aloud and discussed how the ads related to important issues in interpersonal research (e.g., how men and women respond differently when reporting sexual partner preferences, but not long-term dating or marriage preferences). Pre- and postactivity knowledge measures indicated that the activity increased students' knowledge of interpersonal relationship research. In addition, students evaluated the activity as a fun, valuable, and interesting learning experience.
Altered Contractility of Rabbit Penile Corpus Cavernosum Smooth Muscle by Hypoxia

AbstractPurpose: To investigate the effects of severe hypoxia on trabecular smooth muscle contractility.Materials and Methods: Strips of rabbit corpus cavernosum were mounted in organ chambers to measure isometric tension. In some experiments intracellular free Ca2+ concentration and tension were measured by the intracellular fluorescent dye FURA-2 and isometric tension recording simultaneously.Results: Contractions elicited by norepinephrine, endothelin-1 or potassium were attenuated under hypoxic conditions (pO2 approximately 10 mm. Hg). Strips contracted with 20 mM. K sup + under normoxic conditions and then exposed to hypoxia consistently lost the potassium-induced tone. The hypoxia-induced relaxation was not affected by the removal of the endothelium, by treatment with the cyclooxygenase blocker, indomethacin, or with the guanylate cyclase blocker, methylene blue. The potassium channel opener, cromakalim, and adenosine relaxed potassium contracted strips; however, the potassium channel blockers glibe...
Failure of hyaluronidase to alter the early course of acute myocardial infarction in pigs.

Abstract The effect of hyaluronidase on the early course of acute myocardial infarction was evaluated in closed chest anesthetized pigs. One hour after balloon catheter occlusion of the left anterior descending coronary artery, hyaluronidase (500 units/kg body weight) was rapidly infused in 10 animals while 9 received no treatment. The animals were then observed over the next 4 hours. Cardiac output, heart rate, mean arterial pressure and left atrial pressure were not significantly affected by treatment. Heart rate increased and arterial pressure decreased in each group to a comparable degree by 5 hours, but left atrial pressure and cardiac output were unaffected. Precordial S-T segment mapping revealed no significant difference between the two groups. S-T segments rose to a comparable degree in each group and peaked before 1 hour. Hyaluronidase had no acute effects on the S-T segment map in the first 30 minutes after infusion or during the subsequent return of the map toward control level. Slightly lower S-T segments in the hyaluronidase-treated group at 5 hours was of borderline significance but was attributed to factors other than the drug intervention. Changes in ventricular wall motion were assessed angiographically, and all animals manifested akinetic or dyskinetic segments. A significant reduction in shortening fraction of involved segments was seen after occlusion, but no difference was observed between the two groups at 5 hours. Shortening fraction of the combined anterior and anteroapical segments decreased from 66 ± 10 to 20 ± 6 percent at 5 hours in the hyaluronidase group (no. = 7) whereas in the control group (no. = 6) it decreased from 68 ± 6 to 28 ± 9 percent. Comparable increases in end-dlastolic volume were also present at 5 hours in each group. Volumes increased from 80.6 ± 5.1 to 97.5 ± 6.4 ml 3 at 5 hours ( P 3 ( P Hyaluronidase did not alter the early course of acute myocardial infarction in pigs. Species differences may contribute to different results reported to date.
Effects of an Atrazine, Metolachlor and Fipronil Mixture on Hyalella azteca (Saussure) in a Modified Backwater Wetland

We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a pesticide mixture of atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first 2 h of amendment at the upstream amendment site but not at any time at the downstream site. H. azteca survival varied spatially and temporally in conjunction with measured pesticide mixture concentrations. Hyalella azteca 96 h survival pesticide mixture effects concentrations ranges were 10.214–11.997, 5.822–6.658, 0.650–0.817, and 0.030–0.048 μg L−1 for atrazine, metolachlor, fipronil, and fipronil-sulfone, respectively.
Technological Gap and Uneven Accumulation in a Classical Production Model

Two regions are distinguished by their technological capabilities. In autarky, the advanced region accumulates more rapidly. Trade augments both regions' growth rates, but can initially worsen the uneven accumulation. The advanced region's faster growth turns the terms of trade against itself. The growth gap narrows. Yet, trade can never close that gap completely. Further decline in the advanced region's growth rate is arrested by its investment in, and technology transfer to, the backward region to augment the latter's export. Whether uneven accumulation persists depends on how successfully the backward region's indigenous capitalists adopt the more efficient `foreign' technology.
SLIM: Blending Technologies to Create Better Learning Experiences

Using technology in education can help prepare nurses to meet the demands of the nursing shortage in the 21st century. Because boards of nursing approve nursing education programs in most states, regulators play an important role in the use of innovative teaching strategies for nursing curricula. Simulation, one type of technology that is growing rapidly in popularity, is designed to give students learner-centered education in which they direct their experience. To better prepare students for a simulation session, the authors developed simulation learning interactive modules (SLIMs). SLIMs are short, eLearning modules created using an instructional design framework for reviewing specific skills needed during simulation sessions.The SLIM educational tool had positive effects on students' learning in the simulation setting, reducing the need for faculty intervention, the amount of time required, and the number of students needing to complete the skill addressed in the SLIM. The tool also increased the time available for meeting learning objectives.
Pneumococcal Arthritis and Osteomyelitis in Children

Five children with pneumococcal bone and joint infections are described. Three of the children were less than one year of age and two had sickle cell disease. All but one had a primary or coincident focus of acute pneumococcal infection elsewhere. In the four children with septic arthritis, osteomyelitis was diagnosed subsequently in bones contiguous to the infected joint. All patients were successfully treated, although one developed permanent joint dysfunction. Although an unusual infection, pneumococcal infection of bones and joints should be sought in the appropriate clinical setting since such in fection requires specific surgical therapy and may be associated with signifi cant morbidity.
Synaptic organization of primary axons in trigeminal nucleus oralis

This report examines the morphology and synaptic connections of small-diameter primary trigeminal axons that terminate in the border zone (BZ) and ventrolateral (VL) subdivisions of rat trigeminal nucleus oralis (Vo). Primary axons were made visible for light and electron microscopic analysis by utilizing the method of anterograde transport of horseradish peroxidase. BZ receives the terminal arborizations of two different populations of small-diameter primary axons. One of these arises from unmyelinated parent fibers and terminates in the dorsal one-half of BZ, while the other has small myelinated parent branches that arborize throughout the subdivision. Terminating within VL are the arbors of a second population of small myelinated primary axons. The endings of all three populations of primary axons lie in synaptic glomeruli. Endings in both subdivisions derived from small myelinated parent fibers lie centrally in glomeruli. Those in VL form axodendritic synapses on numerous dendritic shafts and spines, while endings in BZ glomeruli make at least one axodendritic synapse on one or two dendritic shafts. Endings of unmyelinated primary axons in BZ lie at the periphery of glomeruli where each forms a single axodendritic synapse on a central dendrite. It is at these asymmetrical axodendritic synapses that these three populations of primary axons are thought to transfer their inputs directly to the dendritic arbors of second-order BZ and VL neurons. Common to all three glomeruli is one or more small axonal endings filled with flattened synaptic vesicles that establish axoaxonic synapses on the primary ending as well as axodendritic synapses on the dendritic element(s) receiving primary input. In view of their symmetrical to intermediate synaptic contacts, these endings are thought to belong to axons derived from at least one source that can inhibit or diminish the firing rate of second-order BZ and VL neurons in response to primary input.
Performance evaluation of nonrectangular multistage interconnection networks

The performance is considered of unbuffered packet-switching nonrectangular multistage interconnection networks. Performance analysis is based on a simplified model for resolution of packet contention. An approximate closed-form analytical expression for the probability of packet acceptance is derived. Blocking characteristics of nonrectangular networks are analyzed and it is shown that for large nonrectangular networks, the probability of packet acceptance does not degrade with growth of network size. >
Results of a computer simulation of a nonintrusive, optical steam quality monitor

In a steam plant, the liquid phase cannot be completely eliminated from steam produced in the steam generator. Wetness factor, or fraction of total mass in the liquid phase, serves as an indication of plant efficiency and normal operation. During start-up, accidents, or anomalous plant operation, the wetness factor may reach high levels, continually monitoring the wetness factor would allow real time adjustment of plant parameters, improving plant efficiency and reducing maintenance. A nonintrusive, continuous, optical steam quality monitor is proposed for the above problem. The authors examine the feasibility of the proposed monitor by simulating its operation with a computer program. In particular, the intensity of scattered light received by the detectors, and variations of the intensity with changes in wetness, are determined. Various implementations of the monitor are simulated at both high and low pressure. The ratio of steam qualities is found to be nearly linear for a given size-number density distribution. >
Potential living kidney donors' health education use and comfort with donation

Context—Much living kidney donation research focuses on actual donors rather than all donors who are evaluated by the transplant center.Objective—To determine (1) what concerns and benefits potential donors saw possible from donation, (2) how they educated themselves before contacting the transplant center, and (3) who were the most comfortable donors.Design—A telephone survey of 91 potential donors before transplant evaluation.Setting—Barnes-Jewish Hospital Transplant Center in St Louis, Mo.Main Outcome Measures—Willingness and comfort donating, key concerns and perceived benefits to donation, hours of transplant-related education.Results—On a 7-point scale, potential donors were very willing (mean=6.65, SD=0.95) and comfortable (mean=6.31, SD=1.12) donating. They were most concerned that their recipients would die if they could not donate, the evaluation and surgery would be anxiety provoking or painful, and they did not understand what donation would require. Donors previously spent an average of 6 hou...
Market size, service quality and competition in the US downhill ski industry

Using a two-sector model of congestion, I explain theoretically how lower travel costs and increased consumer income over time resulted in endogenous investment in quality and higher real prices at both national and local ski resorts despite limited market entry. I also provide empirical evidence for the US ski industry in support of the implications of the model.