cssi/SciSciGPT-SciSciNet huggingface dataset:
Aging Affects the Ability to Process the Optic Flow Stimulations: A Functional Near-Infrared Spectrometry Study.

Optic flow (OF) has been utilized to investigate the sensory integration of visual stimuli during postural control. It is little known how the OF speed affects the aging brain during the sensory in...
Minimally Invasive Aortic Valve Replacement

With the advent of transcatheter aortic valve replacement and the emergence of rapid deployment aortic valves, there is a resurgent interest in minimizing the trauma of surgical aortic valve replacement (AVR). The present review summarizes the history of minimal access AVR and attempts to collate the existing evidence regarding minimal access AVR.
Metal Nanoparticles as Green Catalysts

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.
Impact of general surgery rotation exposure on surgery clerkship performance

Abstract Background Medical students often have variable exposures to general surgery (GS) and subspecialty surgery (SS) during their surgical clerkship. We will evaluate the relationship between clinical exposure to GS and performance on the NBME Subject Examination in Surgery. Methods Student data was collected retrospectively from 2015 to 2018 at a single academic institution. Students were categorized based on their clinical clerkship exposure to GS. A linear model was used to estimate the mean difference in NBME performance between GS and strictly SS exposed students while controlling for prior standardized examination scores and completion of an internal medicine clerkship prior to surgery. Results 365 (67%) of 547 students were exposed to a GS rotation prior to their NBME exam. Performance on the NBME exam was comparable between GS versus SS students (μdiff = 0.37, 95% CI: −0.73 to 1.48; p = .51). Conclusions Exposure to a GS rotation is not advantageous on the NBME surgery examination. Students who completed the medicine clerkship prior to surgery demonstrated superior performance on the NBME surgery examination.
Thermal stability vs. variability: Insights in oxidative stress from a eurytolerant fish.

Climate change will increase the frequency, intensity, and duration of heatwaves. This thermal volatility will challenge to the oxidative homeostasis of aquatic ectotherms through many temperature-dependent environmental factors. In this study, we examined the effects of chronic exposure of sheepshead minnows (Cyprinodon variegatus) to multiple thermal regimes on the oxidative physiology of white muscle in these eurytolerant fish. The thermal treatments included stable (15 °C and 30 °C) and cycling regimes (between 21 and 29 °C at 6, 8 and 10-h intervals). The effect of these thermal treatments on oxidative stress during an acute thermal challenge (12 h at 32 °C) was also examined. Enzymatic activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), scavenging capacities of hydroxyl and peroxyl radicals, and lipid peroxidation (LPO) damage were quantified. We found no differences between or across treatments in any of the enzymatic antioxidants or LPO damage. We found that peroxyl radical scavenging was greatest at the peak of the 8- and 10-h thermal cycles. Peroxyl scavenging after an acute thermal challenge was greater than before the challenge for the steady 15 °C and 8-h cycle treatments, greater before the acute challenge for the steady 30 °C and 6-h cycle, and equivalent in the 10-h cycle. These findings demonstrate that even the most tolerant of marine ectotherms must engage oxidative defenses when presented with thermal variability and heighten concerns about the impact of climate change on less tolerant species.
What Is Hidden Can Still Hurt: Concealable Stigma, Psychological Well-Being, and Social Support Among LGB College Students

This study examines the importance of social support and psychological well-being for college students and highlights the unique challenges faced by lesbian, gay, and bisexual students. Interacting with members of similar identity groups is crucial in the development of one’s sense of self and place in the social world. However, these benefits are limited for people with a concealable stigma identity, given the increased difficulty of identifying similar others. The current study examined indicators of social support, psychological health (positive affect), and anxiety among college students between 2015 and 2017. To investigate the role of concealable stigma among these factors, responses from students (N = 33) who identified as lesbian, gay, or bisexual (LGB) were compared with responses from heterosexual students (N = 43) who did not consider themselves allies of the LGB community. LGB students reported lower levels of psychological well-being and less social support than their heterosexual peers. The unique difficulties faced by members of concealable stigma groups when needing social support are considered, with the goal of increasing psychological health among college students with a minority sexual orientation.
Triflange Cup and 3-D Printing in THA

The management of pelvic discontinuity in revision total hip arthroplasty can be challenging and requires a thorough understanding of the bone loss pattern as well as available treatment options. The goal of the treatment for large acetabular defects and pelvic discontinuity is to create a unitized hemipelvis by either biological healing of the discontinuity or mechanically fixing the superior and inferior aspects of the pelvis with rigid and durable fixation. This chapter discusses the indications, nuances, and considerations for various treatment approaches for pelvic discontinuities, with special attention to the use of custom triflange implants and the emerging role of 3-D printing technologies in this clinical setting. In addition, this chapter reviews the evolution of 3-D printing, and its surgical application in creating patient-specific implants to best accommodate the remaining host bone and optimize screw purchase. The rationale, manufacturing process, surgical technique, and case examples of custom triflange components, as well as the available midterm survivorship data, are also detailed.
Date Palm Quantitative Trait Loci

Most agronomic traits in plants are quantitatively inherited. Quantitative trait loci (QTL) are chromosome regions associated with a particular phenotypic trait. QTL mapping is used to gain insight into the genetic architecture of complex quantitative traits in plants. Genome-wide association study (GWAS) has become a routine strategy to understand the genetic basis of quantitative traits. QTL mapping and GWAS study requires genotypic and phenotypic data that have been scored across a large number of individuals within a population. Utilization of statistical methods is a crucial step for identifying QTLs or causal genes associated with traits to explain the genetic basis of complex traits. In this chapter, we review current advances and strategies in the QTL mapping such as the creation of various populations, application of different types of DNA markers, collection of phenotypic data, and selection of appropriate statistical software to ensure the execution of association mapping. Association studies between DNA regions and traits can provide an optimistic assessment of the prospects of marker-assisted selection (MAS) employed in plant breeding programs. Candidate genes associated with complex traits can be discovered and cloned after validation of QTLs through the functional study by gene editing or the combination of QTL mapping with RNA-seq.
Older Adults’ Goals and Expectations When Using Long-Term Services and Supports:

ObjectiveDespite recent research focused on aging well, little is known regarding the goals and expectations from long-term services and supports (LTSS) use among older adults.MethodsTo address thi...
On the Effectiveness of Sparsification for Detecting the Deep Unknowns.

Detecting out-of-distribution (OOD) inputs is a central challenge for safely deploying machine learning models in the real world. Previous methods commonly rely on an OOD score derived from the overparameterized weight space, while largely overlooking the role of sparsification. In this paper, we reveal important insights that reliance on unimportant weights and units can directly attribute to the brittleness of OOD detection. To mitigate the issue, we propose a sparsification-based OOD detection framework termed DICE. Our key idea is to rank weights based on a measure of contribution, and selectively use the most salient weights to derive the output for OOD detection. We provide both empirical and theoretical insights, characterizing and explaining the mechanism by which DICE improves OOD detection. By pruning away noisy signals, DICE provably reduces the output variance for OOD data, resulting in a sharper output distribution and stronger separability from ID data. DICE establishes superior performance, reducing the FPR95 by up to 24.69% compared to the previous best method.
Stability of Nonlinear Waves Resonantly Sustained

This talk will examine the stability properties of representative cases of nonlinear dispersive waves generated and sustained at resonance of physical systems capable of supporting solitary waves. The criteria are sought for realizing the remarkable phenomenon of periodic production of upstream-radiating solitary waves by critical disturbances moving steadily in a layer of shallow water as modeled by the forced KdV equation. Of primary interest are the distinctive features of instabilities of a few typical steady basic flows, the salient new characteristics of the associated eigenvalue problems, the relevant nonlinear effects, and the resulting bifurcation diagrams.
A mouse model of gastrointestinal stromal tumor

Proc Amer Assoc Cancer Res, Volume 46, 2005 1977 Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Most GISTSs harbor activating mutations in Kit, a receptor tyrosine kinase (RTK). Rare families have germline activating Kit mutations and family members with these mutations develop interstitial cell of Cajal (ICC) proliferations and GISTs. We have constructed a mouse model harboring a germline activating Kit mutation, which mimics the human familial GIST syndrome. Design: We have a used a genetic knock-in strategy to replace one normal Kit allele with a mutant allele that harbors a K641E mutation. The mutant allele is analogous to a mutation seen in a single human familial GIST syndrome family. Mice harboring this allele were interbred and monitored for the development of abdominal masses or distended abdomens. Mice developing masses or distended abdomens were sacrificed and necropsied per protocol. Tissues were examined by routine histology and by immunohistochemistry with antibodies to Kit, smooth muscle actin, desmin, and CD34. Electron microscopy was performed according to standard procedures. Tumor lysates were immunoprecipitated with an antibody to Kit and western blotted with anti-phosphotyrosine and anti-Kit antibodies. Flow cytometry was performed using an anti-Kit antibody. Results: Viability of the mice depends on whether a neomycin resistance cassette (Neor) is present within intron 13. Mice harboring Neor are viable but differ from the expected Mendelian frequencies, with a statistically significant loss of both K641E heterozygotes and homozygotes. While heterozygous mice carrying the K641E allele without Neor are viable; homozygotes die in utero. All mice carrying mutant K641E alleles express Kit at greatly reduced levels as evidenced by low Kit expression of whole bone marrow and D12.5 liver-derived bone marrow cells. Furthermore, loss of function phenotypes including lack of skin pigmentation, decreased levels of dermal mast cells and sterility are seen in homozygous K641E mutants carrying Neor. Heterozygous K641E mice with or without Neor do not exhibit any loss of function phenotypes. However, 100% of mice harboring one or more K641E alleles with or without Neor develop gastrointestinal pathology to varying degrees, beginning at 4 weeks of age, in the form of ICC proliferations of the gastrointestinal tract and GISTs of the cecum. Kit immunoprecipitation reveals the GISTs to have very high levels of phosphorylated/activated Kit. Conclusion: We have developed a mouse GIST model in which mice develop ICC proliferations and GISTs. This model will be useful in understanding the pathogenesis of GISTs as well as serving as an excellent pre-clinical model to test the efficacy of therapies which target Kit.
Rater Agreement – Kappa

Whether there is agreement or consensus among raters or observers on their evaluation of the objects of interest is one of the key questions in the behavioral sciences. One way to measure rater agreement is to have two raters make independent observations on the same group of objects, to classify them into a limited number of categories, and then to see to what extent the raters' evaluations overlap. Of all measures, Cohen's kappa (κ, 1960) is one of the best known and most frequently used measures to assess the extent of agreement by raters in a summary statement for entire observations. Keywords: kappa; rater agreement
Reconstitution of a nine-protein system that initiates bacteriophage λ DNA replication

Abstract We have established an in vitro system, composed of highly purified bacteriophage lambda and Escherichia coli proteins, that specifically replicates supercoiled templates bearing the lambda replication origin (ori lambda). The complete system is composed of three groups of proteins: the virus-encoded initiator proteins (the lambda O and P proteins), the E. coli replication fork propagation machinery (single-stranded DNA-binding protein, dnaB helicase, dnaG primase, DNA polymerase III holoenzyme, and DNA gyrase), and two bacterial heat shock proteins (dnaJ and dnaK proteins). DNA replication in this system is initiated at or near ori lambda and proceeds unidirectionally rightwards through theta-structure intermediates, ultimately yielding a pair of intertwined daughter circles as the final product. In striking contrast to the situation in vivo and in crude in vitro systems, initiation of lambda DNA replication in the purified protein system does not require "transcriptional activation" of the origin region by E. coli RNA polymerase. We conclude that E. coli primase generates the primers for all leading and lagging strand DNA chains synthesized in this reconstituted lambda replication system.
Universal liquid chromatographic methods : III. Sensitive, low-wavelength gradients with a novel injection-loading ion-pairing technique☆

Abstract This paper extends to the ion-pairing mode the “universal methods” previously reported for the reversed-phase mode. These methods offer savings of laboratory and customer time and cost as they often allow “first run problem solving”, reduce method development for each new problem and allow different separation problems to be run in sequence with no system changes. Major and minor components of unknown wide-polarity mixtures are analyzed with the near-universal detection possible at 210 nm. A new technique of injection loading an ion-pairing (IP) agent with an automated liquid chromatograph into simple buffered eluents is introduced. Full gradients from aqueous buffers to acetonitrile are achieved at 0.1 a.u.f.s. and 210 nm without ghost peaks or baseline shifts (less than 5%). Additioally, in three consecutive 12-min runs, the three liquid chromatographic modes (with different selectivities), viz. , cation-pairing, anion-pairing and simple reversed-phase, can be explored in order to optimize the separation of a particular sample. The charge of the individual components at the eluent pH can be determined by the movement of peaks in consecutive runs. Other advantages of injection loading are that the pump and column life are preserved, only small amounts of clean ion-pairing agents are required and the effect of new ion-pairing agents on a sample can be investigated in one run. We also present a new technique for achieving flat 210-nm UV baselines. This is accomplished by bubbling a mixture of nitrous oxide (UV absorbing) with helium of a composition that varies the aqueous background UV absorption to match the second gradient eluent, acetonitrile.
A Humanized Anti-Cocaine Monoclonal Antibody Decreases the Urinary Excretion of Cocaine from Mice (LB588)

The recombinant humanized monoclonal antibody (mAb) h2E2 is a lead candidate for immunotherapy of cocaine abuse. This anti-cocaine mAb has been shown in vivo to inhibit cocaine’s distribution to mo...
Chapter 7 Clinical features of myasthenia gravis

Publisher Summary This chapter focuses on the clinical features of myasthenia gravis (MG). Almost all patients with MG seek medical attention because of dysfunction referable to specific muscles. The chapter discusses the symptoms of MG. In most patients with MG, weakness results from the effects of circulating anti-acetylcholine receptor (AChR) antibodies. Binding to AChR is on the terminal expansions of the junctional folds. The antibodies cause complement-mediated destruction of the folds, accelerated internalization, destruction of AChR by antigenic modulation, and blocking of the binding of acetylcholine (ACh) to AChR. Destruction of the junctional folds results in distortion and simplification of the postsynaptic region. The incidence of MG increased over years, due to better diagnostic techniques and treatments. Early and accurate diagnosis of MG is critical in determining and effecting the most appropriate treatment. If antibodies to the AChR or muscle specific tyrosine kinase (MuSK) are found in a patient with weakness, the diagnosis is secure. If no antibodies are found, the diagnosis is made by demonstrating weakness and abnormal neuromuscular transmission (NMT), and excluding other nerve or muscle disease. Autoimmune MG is not a hereditary disease, but, like other autoimmune conditions, occurs more often in family members than by chance alone. Thymus gland plays a role in the induction of tolerance to self-antigens that is the primary abnormality in MG. Thymus contains all the necessary elements for the pathogenesis of most MG: myoid cells that express the AChR antigen, antigen-presenting cells, and immunocompetent T-cells. The chapter gives an account of some special conditions of MG such as ocular myasthenia, childhood MG, seronegative MG, myasthenic crisis, pregnancy in MG, MG in the elderly, and induced MG.
Childhood Sexual Abuse as a Risk Factor for Subsequent Involvement in Sex Work

Abstract The following paper is a review of research studies examining the relationship between childhood sexual abuse (CSA) and subsequent involvement in sex work. The vast majority of research studies in this area are conducted on primarily female street-based prostitutes; however, there has been a recent emergence of studies focused on male, predominantly gay/bisexual, participants. Also, more studies have begun to include mixed gender samples and non-sex worker comparison groups. Highlights of the paper include a critique of studies reporting a prevalence of CSA, the intervening effects of family environment, runaway behavior, and abuse characteristics, and a brief overview of research on other sex worker populations. Limitations as well as contributions of current studies are underscored and directions for future research are indicated.
Distributed synthesis of fault-tolerant programs in the high atomicity model

In this paper, we concentrate on distributed algorithms for automated synthesis of fault-tolerant programs in the high atomicity model, where all processes can read and write all program variables in one atomic step. Although there has recently been an increasing interest in using parallel and distributed techniques in the model checking community, these technique have not been investigated in program synthesis. Developing such techniques is crucial as a means to cope with the state explosion problem in the context of program synthesis and transformation as well. We propose two distributed multithreaded algorithms for adding two levels of fault-tolerance, namely failsafe and masking, to existing fault-intolerant programs whose state space is distributed over a network or cluster of workstations.
Multi-mode detection with Markov target motion

This paper addresses the problem of the configuration of a detection system offering multiple modes of operation that differ in their detection performance and geographical coverage. A technique for optimal mode selection based upon minimizing Bayesian risk is formulated and demonstrated for the case of a two-mode system with a moving target. The dynamics of the target are described by a Markov model.
Dissecting the contribution of EBNA3C domains important for EBV-induced B-cell growth and proliferation

Epstein-Barr virus (EBV) is an oncogenic gammaherpes virus which is linked to pathogenesis of several human lymphatic malignancies. The EBV essential latent antigen EBNA3C is critical for efficient conversion of primary human B-lymphocytes to lymphoblastic cell lines and for continued LCL growth. EBNA3C, an EBV latent antigen with oncogenic potential can bind and regulate the functions of a wide range of cellular transcription factors. In our current reverse genetics study, we deleted the full length EBNA3C, and independently the RBP-Jκ and Nm23-H1 binding sites within EBNA3C using BACmid recombinant engineering methodology. Our experiments demonstrated that deletion of the EBV EBNA3C open reading frame (ORF) and more specifically the residues 621-675 which binds Nm23H1 and SUMO-1 showed a significant reduction in the ability of the cells to proliferate. Furthermore, they exhibited lower infectivity of human peripheral blood mononuclear cells (PBMCs). We also showed that recombinant EBV with deletions of the EBNA3C ORF, as well as a recombinant with residues 621-675 within EBNA3C ORF deleted had diminished abilities to activate CD40. Our study also revealed that the full length (1-992) and 621-675 aa deletions of EBNA3C when compared to wild type EBV infected PBMCs had differential expression patterns for the phosphorylation of MAP kinases specifically p38, JNK and ERK. Regulation of β-catenin also differed among wild type and EBNA3C deleted mutants. These temporal differences in signaling activities of these recombinant viruses in PBMCs is likely important in defining their functional importance in EBV-mediated B-cell transformation.
Angiography in a case of hydranencephaly

Summary A case of hydranencephaly in which angiography was done is reported to show that in this patients the vascular pattern like that of the cranium and meninges is intact. The picture of the pneumoencephalogram taken with the patient upside down reveals clearly the extent of the destruction. There was no evidence of vascular anomaly, of infection, or toxic inflammation to indicate these factors as a role in etiology, thus leaving congenital cystic formation within the cerebral tissue as the most likely cause.
Tamoxifen for breast cancer prevention

The case for tamoxifen to be tested as a preventive for breast cancer has merit. Animal studies demonstrate that tamoxifen prevents mammary carcinogenesis and clinical studies now confirm that adjuvant tamoxifen therapy is the only systemic treatment that will prevent contralateral breast cancer. Developing clinical studies confirm the laboratory data that tamoxifen will maintain post-menopausal bone density in the lumbar spine and the neck of the femur; two important skeletal sites for the ultimate prevention of osteoporosis. However, a most important target site-specific effect of tamoxifen is the decrease in low-density lipoprotein cholesterol levels in postmenopausal women. This positive property of tamoxifen may be responsible for the recorded decreases in hospital visits for the treatment of cardiac conditions and the significant decrease in fatal myocardial infarction for women treated with 5 years of adjuvant tamoxifen. These data provide the scientific basis to undertake randomized, placebocontrolled clinical trials to test the worth of tamoxifen to prevent breast cancer.
Germanium Contents of USGS Standard Rocks by Flameless Atomic Absorption

Germanium in 13 USGS standard silicate rooks was determined by flameless atomic absoprtion using a procedure which permits the determination of 0.2 ppm of germanium in as little as 50 mg of sample. The mean germanium content found is (in ppm Ge) for the new USGS standards: BHVO-1, 1.60; SDC, 1. 51; STM-1, 1. 32; QLO-1, 1. 28; RGM-1, 1. 24; and for- the older USGS standards: W-l, 1.S3; BCR-1, 1.39; G-l, 1.19; GSP-1, 1.16; AGV-1, 1.06; G-2, 0.96; PCC-1, 0.80; DTS-1, 0.72.
Intel 8097 based controller for an XY plotter

Abstract This paper describes the implementation and evaluation of an Intel 8097 based controller for an XY plotter. The plotter utilized two stepper motors to drive its two axes and a solenoid for the pen up/pen down functions. A pulley mounted on the shaft and a steel wire belt were used to translate the steps of the motor to the platform with the pen holder. Driver circuits for the motor and the solenoid were developed and implemented. Microcomputer hardware was developed to implement the control system for the plotter. Algorithms for linear and circular contouring, which were adapted from Brensenham's raster scanning algorithms, were implemented for the discrete step motion. They were translated into pl / m -96, the programming language for this particular microcontroller. The system developed is capable of drawing geometric shapes utilizing the primitives developed. These concepts along with the software implementing the drawing algorithms can be used for a computer numerical control machine.
Neuronal calcium homeostasis and dysregulation.

Abstract The calcium ion (Ca2+) is the main second messenger that helps to transmit depolarization status and synaptic activity to the biochemical machinery of a neuron. These features make Ca2+ regulation a critical process in neurons, which have developed extensive and intricate Ca2+ signaling pathways. High intensity Ca2+ signaling necessitates high ATP consumption to restore basal (low) intracellular Ca2+ levels after Ca2+ influx through plasma membrane receptor and voltage-dependent ion channels. Ca2+ influx may also lead to increased generation of mitochondrial reactive oxygen species (ROS). Impaired abilities of neurons to maintain cellular energy levels and to suppress ROS may impact Ca2+ signaling during aging and in neurodegenerative disease processes. This review focuses on mitochondrial and endoplasmic reticulum Ca2+ homeostasis and how they relate to synaptic Ca2+ signaling processes, neuronal energy metabolism, and ROS generation. Also, the contribution of altered Ca2+ signaling to neurodege...
The effects of caregiver emotional stress on the depressive symptomatology of the care recipient

Objectives: Depression is a leading mental health issue affecting elderly individuals worldwide. Previous research widely neglects caregiver emotional stress as a probable contributing factor of depression in the elderly. This study investigated caregiver emotional stress as a chronic life stressor of an elderly care recipient using the life stress paradigm as the theoretical foundation.Methods: The relationships between caregiver emotional stress and care receiver depressive symptoms, as well as other social and psychological mediation factors, were investigated using the 2004 wave of the National Long-Term Care Study (NLTCS). The NLTCS is a nationally representative longitudinal study used to identify frail and disabled elderly Medicare recipients living in the United States. The analytic sample of this study included 1340 caregiver–care receiver dyads who were asked a series of questions concerning their mental health (i.e. emotional stress and depressive symptoms), as well as the availability of socia...
Successful Radiofrequency Ablation of Idiopathic Left Ventricular Tachycardia at a Site Away From the Tachycardia Exit

Abstract Objectives. This study sought to assess the possibility of ablating verapamil-responsive idiopathic left ventricular tachycardia at a site distant from the tachycardia exit and thus to define the tachycardia circuit. Background. The nature of the reentry circuit in idiopathic left ventricular tachycardia is unclear. If the circuit is of considerable size, then it should be possible to ablate the tachycardia at a site distant from the exit site. Methods. Electrophysiologic studies and radiofrequency ablation were performed in 27 consecutive patients with verapamil-responsive idiopathic left ventricular tachycardia. In all 27 patients, the tachycardia exit site was defined as the site where the earliest Purkinje potential was recorded ≥25 ms before the onset of the QRS complex during the tachycardia and where the pace map QRS complex resembled that during the tachycardia. A potential ablation site other than the exit site was then sought around the midseptum, proximal to the exit site. At such sites the tachycardia could be terminated transiently by pressure applied to the catheter tip, without induction of ventricular ectopic beats. Results. The potential ablation site, other than the tachycardia exit site, was identified in seven male patients (mean [± SD] age 31 ± 12 years, range 13 to 52). Application of the radiofrequency current at this site resulted in termination of the tachycardia within 1 to 5 s (mean 2.9 ± 1.6), and successful ablation of the tachycardia was achieved in all seven patients (success rate 100%, 95% exact confidence interval 0.5898 to 1). The mean distance between the ablation site and the tachycardia exit site was 3.1 ± 0.7 cm (range 2.0 to 4.0). A presystolic Purkinje spike was recorded 14 ± 5 ms (range 8 to 20) before the onset of the QRS complex during the tachycardia. During the follow-up period of 24 ± 11 months (range 12 to 39), there was no recurrence of tachycardia in these seven patients. Conclusions. Successful ablation of idiopathic left ventricular tachycardia can be achieved at sites away from the tachycardia exit site in some patients. This finding suggests that the reentry circuit is likely to be of considerable size, encompassing the middle, inferior and lower aspects of the left interventricular septum.
Renal vascular effects of antihypertensive therapy in uninephrectomized SHR

Renal vascular effects of antihypertensive therapy in uninephrectomized SHR. Serial determinations of protein excretion rate and systolic blood pressure (SBP) were made in spontaneously hypertensive rats (SHR) uninephrectomized (UNX) at six weeks of age and given tap water (CON), or water with hydrochlorthiazide, hydralazine and reser-pine (HHR), captopril (CAP) or enalapril (ENP). Compared to CON, significant hypertension was prevented, kidney weight was lower and there was less proteinuria in HHR, CAP and ENP rats followed for 30 weeks after UNX. Morphologic studies of these four groups revealed that antihypertensive therapy reduced the incidence of glomerular sclerosis in UNX SHR by 50%. Despite complete absence of systemic hypertension, there was striking medial thickening of lobular arteries and arterioles of rats given the angiotensin converting enzyme (ACE) inhibitor, captopril. These vascular abnormalities were present to a lesser degree in rats given ENP, but were entirely absent in untreated animals or in those ingesting the HHR combination. Micropuncture studies performed five weeks after UNX in four additional groups of CON, HHR, CAP and ENP rats revealed that glomerular capillary pressure was elevated in CON and reduced by all three drug regimens. These studies support the hypothesis that glomerular capillary hypertension and/or nephron hypertrophy predispose to glomerular injury in this model of hypertension and reduced renal mass. ACE inhibitors and HHR are equivalent in their ability to prevent glomerular hypertension and damage in these rats, but the former, and in particular captopril, produce abnormalities of cortical vessels via a mechanism not dependent on the presence of systemic hypertension.
REFLEX BRADYCARDIA AND HYPOTENSION PRODUCED BY PROSTAGLANDIN F2α IN THE CAT

1 Intravenous administration of prostaglandin F2alpha results in a dose-dependent increase in pulmonary arterial pressure, decrease in systemic arterial pressure and a delayed bradycardia. Pulmonary vasoconstriction was observed at doses as low as 0.1 and 0.3 mug/kg. The systemic depressor and heart rate lowering effects were observed at 1 mug/kg doses and above. 2 A moderate bradycardia was still observed after atropine blockade but was abolished following bilateral vagotomy. Neither of these procedures affected the pulmonary vascular response. 3 Injections of submaximal doses of prostaglandin F2alpha (1--4 mug/kg) produced a greater and longer lasting bradycardia when injected into the left atrium than was observed following intravenous administration. In addition the latency of onset was much shorter following left atrial injection. These doses resulted in no change in heart rate and a minimal hypotension when injected into the brachiocephalic artery or into the aortic arch. 4 Small doses of prostaglandin F2alpha administered at the level of the origin of the coronary arteries produced marked decreases in heart rate and blood pressure whereas no change occurred following injection of the same amount into the ascending aorta at more distal sites. 5 These results suggest that prostaglandin F2alpha produces bradycardia and hypotension in the cat by activating 'receptors' located in the left heart or by acting on structures perfused by means of the coronary arteries.
Gas effects on void formation in 14 MeV nickel ion irradiated pure nickel

Abstract Nickel samples with various helium and oxygen concentrations have been irradiated with 14 MeV Ni ions at 500 °C to a fluence of 8 × 10 19 ions/m 2 (2 dpa at a 1-μm depth). Helium atoms with energy varying from 200 to 700 keV were pre-injected at room temperature. The samples with low oxygen content were obtained by a hydrogen reduction treatment and high vacuum outgassing. The density and the average diameter of voids were determined by TEM examination of cross-section specimens. In the as-received Ni which was cold-worked, a heterogeneous void distribution was observed that could be attributed to the heterogeneous oxygen distribution. In the specimen irradiated after vacuum annealing at 800°C for one hour, voids are uniformly distributed. Small amounts of helium (10 appm) enhanced the void nucleation remarkably in both high (180 appm) and low (75 appm) oxygen content samples, while larger amounts of helium (30 appm) reduced the observable void density in the high oxygen content sample. The void density is much lower and the void size is much larger in the low oxygen content samples compared to those observed in the high oxygen content samples.
Sample Size Requirements for Seismic and Traditional Testing of Concrete Pavement Strength

The strength of portland cement concrete (PCC) is one of the major acceptance quality characteristics in most existing specifications and quality assurance programs for PCC pavement. A statistical method is provided for determining the sample size requirements for reliable estimates of PCC parameters for pavement strength. These parameters include compressive strength from cylinders, flexural strength from beams, and dynamic seismic modulus from both portable seismic pavement analyzer and the free-free resonant column seismic nondestructive testing (NDT) methods. The sample size, which refers to the number of tests or measurements for each quality characteristic taken randomly from a lot, is a function of specifications tolerance, buyer's (i.e., agency's) risk, seller's (contractor's) risk, and the standard deviation of the test parameter under consideration. In practice, sample size typically is set on the basis of practical considerations and engineering judgment. Although practicality is an important c...
Evaluating Randomized Trials of Screening

A smoker requests a screening chest x-ray because he has read that it will lower his chances of developing lung cancer. Later, a female patient asks your opinion about screening mammography. And at the end of day, a patient returns his stool hemeoccult cards unused because he found obtaining the specimen distasteful. How should you respond to the foregoing scenarios? What data are available on these and other screening strategies? Screening, the systematic examination of asymptomatic persons to detect and treat subclinical disease, has become the primary weapon in the battle to prevent disease. Currently the U.S. Preventive Services Task Force offers guidance on more than 50 screening tests,1 and the ongoing development of genetic testing provides a hint of the boundless opportunities for screening in the future.2 The potential for exponential growth alone provides a strong motivation for physicians to be able to critically interpret evaluations of screening.3 But there are other reasons to carefully scrutinize screening strategies. First are the unique implications of screening for the population as a whole. Target disorders are relatively rare, and to find disease, many people must be screened. Unforeseen risks, however rare or minor, are compounded as they apply to all who are screened, while benefits accrue to only a few. Second, cursory evaluations of screening are subject to powerful biases that almost always favor the more intensive screening options.4 Finally, there is the implied pledge of prevention given individuals who are well.5,6 While symptomatic patients generally ask for our help, with screening we are telling asymptomatic people that they need our help. For these people there is an implied promise of future disease prevention—namely, that the screening strategy works. In this article, we offer clinicians a framework to evaluate how realistic such a promise might be using the research evidence from randomized trials.
Microcystic meningioma of the falx cerebri with numerous palisaded structures: An unusual histological pattern mimicking schwannoma

We report a microcystic meningioma of the falx cerebri which had an unusual histological pattern. It contained numerous palisaded structures in loose areas, giving the appearance of the loose and dense areas of a schwannoma. There were minimal meningeal whorls. Ultrastructural study confirmed the totally meningiomatous nature of this tumor.
The timing of adoptions of land-use plans and regulations in Pennsylvania localities

Objective. This article explores the relationship between the timing of land-use tool adoptions and local growth. Methods. Land cover data, census data, and information about land-use tools were merged for all Pennsylvania minor civil divisions (MCDs) for the period 1975/1980 to 1990/1992. First, the extent to which growth was absorbed in MCDs without land-use tools was assessed. Second, the importance of structural changes for distinguishing new adopters and nonadopters was analyzed using a subset of MCDs. Results. Both the aggregateand MCD-level analyses suggested that nonadoptions under growth pressure were not widespread. Growth was not a necessary condition, however, for adoption. Conclusions. The findings support an emphasis on outreach aimed at improving the effective use of existing tools, but suggest that the importance of improving the capacity of MCDs without tools is increasing with population decentralization. When compared with the previous decade, migration from metropolitan (metro) to adjacent and amenity-rich nonmetropolitan (nonmetro) counties increased during the 1990s (Frey and Johnson, 1998; Fuguitt et al., 1998). This trend is projected to continue. Although it presents opportunities for rural development, low-density settlement patterns can undermine such prospects and pose challenges for natural resource management. These include the fragmentation of ecological, aesthetic, and working landscapes, as well as increased water and air pollution (Beatley, 2000; Daniels, 1999; U.S. Environmental Protection Agency, 2001). Growth management policies, popularized in recent years as smart growth, have long been advocated as a means to capture the benefits of growth while minimizing its negative impacts (Daniels, 1999; Porter, 1997). These policies refer to a combination of public spending programs, regulations, and incentives intended to guide the timing, location, and nature of
Comparison of Cognitive Structural Measures for Predicting Person Perception

In a general college population, two measures of cognitive differentiation and two measures of cognitive integration were compared with each other and were used to predict integration of discrepant information in a standard person-perception task. The magnitude of the intercorrelations was very low, with no indication that differentiation measures correlated more with each other than with integration measures. Similar to the results obtained using other global trait measures of personality, the regression analysis employing these cognitive measures showed a low positive correlation with the impression task. The need for a reexamination of the conceptual relationships among these measures and the need to examine the conditions which influence the predictive ability of cognitive measures is discussed.
Nonsteroidal Anti-Inflammatory Drug Use and Alzheimer's Disease: A Case-Control Study in Rochester, Minnesota, 1980 Through 1984

Objective To compare the frequency of use of nonsteroidal anti-inflammatory drugs (NSAIDs) among 302 incident cases of Alzheimer's disease (AD) and age- and sex-matched control subjects. Design We undertook a retrospective case-control study, using the resources of the Rochester Epidemiology Project. Material and Methods In ongoing studies of dementia in Rochester, Minnesota, we identified all incident cases of AD with onset between 1980 and 1984. From among all Rochester residents who received care at Mayo Clinic Rochester during those years, we selected one age- (within 3 years) and sex-matched control subject. For this study, exposure to a, prescription NSAID was defined as prescribed use for 7 or more days during the 2-year window of time encompassing the year of onset and the year before onset among cases and the corresponding index year and the year prior for control subjects. Results The odds ratio (OR) for exposure, as described, to a prescription NSAID versus no exposure to any NSAID was 0.79 (95% confidence interval \[CI), 0.45 to 1.38); the OR was 1.00 (95% CI, 0.52 to 1.92) for women and 0.40 (95% CI, 0.13 to 1.29) for men. Similarly, the overall OR for aspirin exposure versus no NSAID exposure was 0.90 (95% CI, 0.54 to 1.50). Conclusion These data are suggestive but not confirmatory of a protective effect of NSAIDs for AD.
Drinking and Stress: An Examination of Sex and Stressor Differences Using IVR-Based Daily Data

Abstract Background Research on the relation of stress to alcohol consumption is inconsistent regarding the direction of effects, and this association has been shown to vary by sex and type of stress. We sought to build upon the stress–drinking literature by examining the direction of the stress–drinking association over time as well as sex and stressor differences using daily data. Method 246 heavy drinking adults (67% men) aged 21–82 reported daily stress levels and alcohol consumption over 180 days using Interactive Voice Response (IVR). Baseline daily hassles were examined as an alternative measure of stress. Generalized estimating equations (GEEs) were conducted to test the stress–drinking association accounting for alcohol dependency at baseline and sex and stressor type as moderators. Results IVR daily stress predicted increased alcohol consumption the following day, whereas baseline level of daily hassles did not. Examining the opposite direction of effects, IVR ratings of daily alcohol consumption predicted decreased next-day stress. Stress predicted higher alcohol consumption the next day for men but there was no significant association for women. For both sexes, drinking predicted decreased stress the next day, but this effect was stronger for women. Conclusions This study generally supported the drinking to cope and self-medication hypotheses, with findings that increased stress led to increased drinking. The time-varying relation between stress and alcohol appears to be sex- and measure-specific, however. Therefore, interventions targeted at stress management found to be effective for one sex should not be presumed to be applicable to the other.
A structural model for the high-valent intermediate Q of methane monooxygenase from broken-symmetry density functional and electrostatics calculations

A combined broken-symmetry density functional and electrostatics approach has been used to construct a model for the high-valent diiron intermediate Q of methane monooxygenase. The presence of high-spin or intermediate spin iron centers gives rise to two structurally distinct spin-coupled states of the cluster for which calculated geometries, net spin populations, Heisenberg J values, Mossbauer isomer shifts, and quadrupole splittings are compared and contrasted with the available spectroscopic data.
Species and temperature profiles in a differential sphere bed reactor for the catalytic partial oxidation of n-octane

Abstract A method is developed by which temperature and species profiles are measured for the catalytic partial oxidation (CPO) of n -octane in a differential manner in a fixed bed of Pt and Rh-coated α-alumina spheres with a minimum resolution of 1 mm (or ∼0.4 g) of catalyst over a wide range of feed stoichiometries. Results indicate that two regions of catalytic activity are present in the bed: a short (∼1 mm) oxidation zone in the front of the bed and a longer reforming zone downstream. The lengths of the reforming and oxidation zones are dependent on the stoichiometry of the reactor feed. O 2 is consumed rapidly on both Rh and Pt catalysts; however, full O 2 conversion is reached faster on Rh than on Pt. Both steam reforming and dry (CO 2 ) reforming are observed in the bed downstream of the oxidation zone, but steam reforming is more extensive because higher conversions of H 2 O are observed than CO 2 on both Rh and Pt catalysts. The conversion of H 2 O and CO 2 in the reforming zone is always higher on Rh than on Pt, therefore Rh is a better reforming catalyst than Pt. Low molecular weight hydrocarbons like methane and ethylene are more readily reformed than octane. Results also indicate that alumina sphere beds are better supports for syngas production than alumina foam monoliths.