cssi/SciSciGPT-SciSciNet huggingface dataset:
High Tibial Osteotomy with a Modern Polyetheretherketone (PEEK) System: Mid-Term Results at a Mean of 6 Years Follow-Up

The purpose of this study was to determine patient-reported outcomes, hardware removal rates, as well as conversion to arthroplasty at mid-term follow-up following high tibial osteotomy (HTO) with a modern polyetheretherketone (PEEK) system. All PEEK system-based HTOs performed at a single institution between January 2010 and January 2016 with a minimum of 2 years follow-up were reviewed. Rates of postoperative complications, hardware removal and conversion to arthroplasty were calculated. Patient-reported outcomes including visual analog pain scale (VAS), Tegner activity scale, Lysholm, Knee Injury and Osteoarthritis Outcome Score (KOOS), and 36-Item Short Form Survey (SF-36) were obtained. Forty-seven HTOs in 43 patients (mean age: 37.6 ± 10.8 years; 30 M, 13 F) were followed for a mean of 6.0 ± 1.5 years. A total of four postoperative complications occurred in three patients, resulting in an overall complication rate of 6.4%. Hardware removal occurred in three patients at a mean of 0.73 ± 0.53 years after surgery, with overall survival free of hardware removal of 96% (95% confidence interval [CI]: 85–99) at 1 year, 94% (95% CI: 82–98) at 2 years, and 94% (95% CI: 82–98) at 8 years. Conversion to arthroplasty occurred in three patients at a mean of 3.2 ± 1.0 years after surgery, with mean survival of 100% (95% CI: 94–100) at 1 year, 100% (95% CI: 94–100) at 2 years, and 93% (95% CI: 81–98) at 8 years. VAS at rest improved, from 3.1 ± 2.5 preoperatively to 1.1 ± 1.6 postoperatively (p
The impact of physical activity during pregnancy on labor and delivery.

Background Physical activity in pregnancy is associated with decreased risks of adverse pregnancy outcomes such as gestational diabetes and preeclampsia. However, the relationship between the amount and type of physical activity during pregnancy and subsequent labor outcomes remains unclear. Objective This study aimed to test the hypothesis that higher levels of physical activity across different lifestyle domains in pregnancy are associated with a shorter duration of labor. Study Design This study is a secondary analysis of a prospective cohort study in which patients with singleton pregnancies without a major fetal anomaly were administered the Kaiser Physical Activity Survey in each trimester. The Kaiser Physical Activity Survey was designed specifically to quantify various types of physical activities in women and includes 4 summative indices—housework/caregiving, active living habits, sports, and occupation. The study included women at full-term gestations admitted for induction of labor or spontaneous labor. The primary outcome of this analysis was duration of the second stage of labor. Secondary outcomes were duration of the active stage, prolonged first and second stage, mode of delivery, rates of second-stage cesarean delivery, operative vaginal delivery, severe perineal lacerations, and postpartum hemorrhage. These outcomes were compared between patients with and without high physical activity levels, defined as overall Kaiser Physical Activity Survey score ≥75th percentile in the third trimester. Multivariable logistic regression was used to adjust for obesity and epidural use. In addition, a subgroup analysis of nulliparous patients was performed. Results A total of 811 patients with complete Kaiser Physical Activity Survey data in the third trimester were included in this analysis. The median Kaiser Physical Activity Survey score was 9.5 (8.2–10.8). Of the 811 patients, 203 (25%) had higher levels of physical activity in pregnancy. There was no difference in the duration of the second stage of labor between patients with and without higher physical activity levels (1.29±2.94 vs 0.97±2.08 hours; P=.15). The duration of active labor was significantly shorter in patients with higher levels of physical activity (5.77±4.97 vs 7.43±6.29 hours; P=.01). Patients with higher physical activity levels were significantly less likely to have a prolonged first stage (9.8% vs 19.4%; P Conclusion Patients who are more physically active during pregnancy have a shorter duration of active labor.
Nonparametric Estimation of Price Elasticities: A Heterogeneous Treatment Effect Approach

We revisit the classical problem of price elasticity estimation from a causal perspective. When the price is perceived as a continuous but endogenous treatment, the flexible estimation of price elasticity can be turned into the estimation of heterogeneous treatment effects. To this end, we develop a control function approach to deal with treatment endogeneity when estimating heterogeneous treatment effects. This strategy works by breaking the estimation of price elasticity into several intermediate problems of point-wise expectation estimation, where modern machine learning methods, such as deep neural networks and random forests, can be used for prediction. In addition, we prove that if we use the bagged nearest neighbors for point-wise prediction, the standard bootstrap procedure can be directly employed to derive inference for the price elasticity estimates. Finally, we apply our method to the IRI academic dataset on two national brands of yogurt. It is found that the competitor's yogurt in a similar size is more a substitute compared to the own brand's yogurt in a different size.
Embracing the Mole Understanding in a Covariate Relation

The amount of substance expressed in the units of moles is an essential concept in physics and chemistry. Physics students usually acquired a chemistry background in applying the mole concept. However, research shows that the complexity of interpretations of quantities expressed as molar mass or atomic mass makes formulating a dimensional analysis with these ratios unclear to physics students. This study proposes proportional reasoning, instead of ratios, as the main building block to formulate conversion algorithms from microworlds to macroworlds and vice versa. A deductively designed lecture was conducted with a group of (N = 25) freshman college physics students. While on the pretest, only (N = 4, 16%) correctly converted a mass of a substance expressed in kilograms to a number of moles, on the posttest, the percentage of correct answers increased (N = 20, 80%), suggesting that proportional reasoning has the potential to help students understand the conversion processes and improve understanding of the mole as a unit of substance. This study, in its principal form, was published earlier (see Sokolowski, A., International Journal of Physics & Chemistry Education, 11, 85–92, 2019).
REPlanner: Efficient UAV Trajectory-Planning using Economic Reinforcement Learning

Advances in the unmanned aerial vehicle (UAV) design and capability, as well as decreases in the manufacturing cost, have opened up applications of UAVs in various fields, including surveillance, firefighting, cellular networks, and delivery purposes. The uniqueness of UAVs in systems creates a novel set of trajectory or path planning and coordination problems. Environments include many more points of interest (POIs) than UAVs, with obstacles and no-fly zones. We introduce REPlanner, a novel multi-agent reinforcement learning algorithm inspired by economic transactions to distribute tasks among UAVs. This system revolves around an economic theory, in particular an auction mechanism where UAVs trade assigned POIs. We formulate the path planning problem as a multi-agent economic game, where agents can cooperate and compete for resources. We then translate the problem into a partially observable Markov decision process (POMDP), which is solved using a reinforcement learning (RL) model deployed on each agent. As the system computes task distributions via UAV cooperation, it is highly resilient to any change in the swarm size. Our proposed network and economic game architecture can effectively coordinate the swarm as an emergent phenomenon while maintaining the swarm’s operation. Evaluation results prove that REPlanner efficiently outperforms conventional RL-based trajectory search.
California Seismic Safety Commission: Multi-disciplinary Collaboration for Seismic Safety Mitigation

Mitigation creates the basis for community resiliency by lessening the disaster’s toll on the physical environment. For example, the contrasting outcomes of earthquakes in Chile and Haiti demonstrate the value of physical mitigation through building codes and engineering. Policy interventions and governmental mechanisms can enhance the likelihood of mitigation steps being taken in advance of disaster, which in turn improves the resiliency of communities. California’s seismic activity in populated areas has led to the creation of mitigation measures for schools, hospitals, residential and commercial buildings, and infrastructure, which grew from multi-disciplinary collaboration. This collaborative approach is embodied in the California Seismic Safety Commission, which oversees the state’s hazard mitigation plan. The commissioners include representatives from science, engineering, emergency management, and social services who can apply their expertise to the evaluation of potential mitigation measures, work with the legislature for passage and funding of mitigation measures, and work with local governments for the implementation of policies and programs to create resiliency. This chapter evaluates the contributions of multi-disciplinary collaboration to the development of resiliency in California as a model for other states and nations confronted with intractable natural hazards.
Dream Catchers, Love Medicine, and Fancy Dancing

The paper presents an overview of the principles, criteria, and tools needed to develop a Native American studies collection. Included is general advice for retrospective and current collection development, beginning with the identification of a core list of titles. Suggestions for selecting sources for five disciplinary areas in the humanities are offered.
The perils of being ahead of the curve: Impact of GPO monthly catalog records on a university library

Abstract Providing public access to government publications by loading the GPO Monthly Catalog records using various years of both MARCIVE and Brodart tapes in an online public access catalog affects technical and public services in unanticipated ways. While increased public access is a step forward, database implementation and management of GPO records is critical for maintaining bibliographic, authority, and quality control. The eight-year experience of the University of New Mexico is offered in this paper as a case study.
ESD-resilient active biasing scheme for high-speed SSTL I/Os

A bidirectional SSTL I/O which utilizes an active-biasing technique to achieve enhanced ESD resilience is presented. During an ESD event, each vulnerable transistor has an appropriate bias applied to minimize the peak voltage across gate oxide and drain-source regions. Active-bias control circuits can be substituted for secondary protection to improve circuit performance and ESD reliability.
Transactivation of erythroid transcription factor GATA-1 by a myb-ets-containing retrovirus.

Abstract ME26 virus is a recombinant mouse retrovirus construct homologous to the avian E26 virus. Both encode a 135-kDa gag-myb-ets fusion protein which is localized in the nucleus. We have recently shown that ME26 virus can induce erythropoietin (Epo) responsiveness in hematopoietic cells. Mice infected with ME26 virus develop a hyperplasia of Epo-dependent hematopoietic precursor cells from which permanent cell lines can be established. In vitro, ME26 virus specifically induces Epo responsiveness in the interleukin-3-dependent myeloid cell line FDC-P2 by enhancing expression of the Epo receptor (EpoR). In the present study we demonstrate that ME26 virus infection of FDC-P2 cells also results in enhanced expression of beta-globin and the erythroid-specific transcription factor GATA-1, a protein which can transactivate both the EpoR promoter and globin genes. In addition, these cells exhibit a down-regulation of c-myb expression similar to that seen in differentiating erythroid cells. To determine the molecular basis for activation of erythroid genes in ME26 virus-infected cells, we carried out transient expression assays with DNA constructs of either the EpoR promoter of the GATA-1 promoter linked to reporter genes. Our results indicate that while ME26 virus did not directly enhance expression from the EpoR promoter, both it and its avian parent, E26, transactivated the GATA-1 promoter. Furthermore, ME26 virus cooperates with the GATA-1 protein to enhance expression of the EpoR gene. We propose that the mechanism by which ME26 virus induces erythroleukemia involves transactivation of the GATA-1 gene, thus positively regulating the expression of the EpoR and leading to the proliferation of a unique population of Epo-responsive cells. By specifically inducing Epo responsiveness in hematopoietic cells via transactivation of a transcription factor, ME26 virus utilizes a novel mechanism for retrovirus pathogenesis.
Scholarly Articles Featuring Projects Using Dublin Core

In this study, a content analysis of scholarly articles concerning projects using Dublin Core was conducted. Areas addressed include whether the projects used a simple metadata schema, whether they were interdisciplinary, whether they were international in scope, and whether they utilized additional metadata schemas. The article addresses the question of whether catalogers of Internet resources are utilizing the Dublin Core as the creators expect. Included is an annotated bibliography detailing some projects using the Dublin Core, with descriptor terms assigned at the end of each annotation.
Effect of Methionine Hydroxy Analog Feeding on Yield and Composition of Bovine Milk

Abstract Four percents of methionine hydroxy analog were fed to 36 lactating Holstein cows in a switch-back experiment of four treatments. The analog contents of the four grain mixtures for treatments I, II, III, and IV were 0, .3, .4, and .5%. The basal ration of corn silage and hay was group-fed ad libitum. Means of the respective treatments were: analog intake 0, 16.59, 23.20, 27.85 g/day and fat-corrected milk 15.8, 16.0, 16.2, 16.1 kg/day. No advantage was found from feeding analog as measured by milk yield, milk fat, or solids-not-fat. No differences were significant among treatments for fatty acid composition of the milk fat.
Metal loproteases in remodeling of vascular extracellular matrix

Abstract The matrix metalloproteinases (MMPs) constitute an ever growing family of related enzymes which degrade various components of the extracellular matrix (ECM). Since ECM catabolism is a basic requirement for tissue shaping early, during organ development, as well as later, during physiological and pathological remodeling, the action of MMPs is seemingly ubiquitous and recurring. This review will concentrate on the remodeling action of MMPs in the cardiovascular system: a topic which has come under scrutiny more recently. As in the case of other organs, the matrix-degrading action of vascular MMPs in the vessel wall can be both beneficial, by allowing their physiologic adaptation and healing, as well as detrimental, when assisting many of the pathologic processes ultimately leading to the structural destruction of blood vessels. These actions may be remarkably similar or overlap during the natural evolution of vascular diseases, to the point that it is often difficult to draw a line that clearly separates them. Vascular MMP production by normal cellular components of the healthy vessel wall is augmented and supplemented in pathological conditions by the contribution of inflammatory cells which infiltrate the diseased vessel wall. Many of the factors found to modulate the expression and enzymatic activation of MMPs in vitro, such as cytokines, growth factors, reactive oxygen species, are know to operate in the setting of atherosclerosis. Accordingly, the biology of vascular MMPs was examined with particular reference to atherosclerosis, a thoroughly-investigated pathological condition of the cardiovascular system.
The Response of Bluegills (Lepomis macrochirus Rafinesque) in a Pollution Monitoring System to a Diurnal Temperature Change

Abstract The breathing and swimming activity rates of four bluegills in a laboratory version of a pollution monitoring apparatus increased when the diurnal temperature cycle changed from a control cycle of 24.8–26.0 C to a treatment cycle of 24.8–29.2 C. The latter cycle simulated the temperature regime reported for the Potomac River in June 1961, at a location free of extraneous thermal effluents. If a bluegill response is being used to detect industrial pollution, critical response values must be determined so that a diurnal temperature change does not cause a false warning signal. The results of this investigation suggest that this can be accomplished.
Feasibility and Safety of Substituting Lung Ultrasonography for Chest Radiography When Diagnosing Pneumonia in Children: A Randomized Controlled Trial.

Background Chest radiography (CXR) is the test of choice for diagnosing pneumonia. Lung ultrasonography (LUS) has been shown to be accurate for diagnosing pneumonia in children and may be an alternative to CXR. Our objective was to determine the feasibility and safety of substituting LUS for CXR when evaluating children suspected of having pneumonia. Methods We conducted a randomized control trial comparing LUS with CXR in 191 children from birth to 21 years of age suspected of having pneumonia in an ED. Patients in the investigational arm underwent LUS. If there was clinical uncertainty after ultrasonography, physicians had the option to perform CXR. Patients in the control arm underwent sequential imaging with CXR followed by LUS. The primary outcome was the rate of CXR reduction; secondary outcomes were missed pneumonia, subsequent unscheduled health-care visits, and adverse events between the investigational and control arms. Results There was a 38.8% reduction (95% CI, 30.0%-48.9%) in CXR among investigational subjects compared with no reduction (95% CI, 0.0%-3.6%) in the control group. Novice and experienced physician-sonologists achieved 30.0% and 60.6% reduction in CXR use, respectively. There were no cases of missed pneumonia among all study participants (investigational arm, 0.0%: 95% CI, 0.0%-2.9%; control arm, 0.0%: 95% CI, 0.0%-3.0%), or differences in adverse events, or subsequent unscheduled health-care visits between arms. Conclusions It may be feasible and safe to substitute LUS for CXR when evaluating children suspected of having pneumonia with no missed cases of pneumonia or increase in rates of adverse events. Trial Registry ClinicalTrials.gov; No.: NCT01654887; URL: www.clinicaltrials.gov
Human thrombin: partial primary structure.

Abstract Human thrombin, prepared from an extrinsically activated prothrombin, was finally chromatographed on an affinity column of p -chlorobenzylamido-ϵ-aminocaproyl agarose. After reduction and s -pyridylethylation, the A and B chains were separated. The A chain contains 36 residues and no carbohydrate and has a formula weight of 4093. Its sequence corresponds to 14–49 of the bovine A chain sequence with nine replacements. Human B chain contains 264 residues. The carbohydrate content is 3.5% neutral sugar, 2.6% glucosamine, and 1.5% sialic acid. High-speed sedimentation equilibrium in guanidine gave a minimum molecular weight of 33,500. Sequenator analysis yielded the first 50 amino-terminal residues and established the positions of three of the cyanogen bromide fragments. A fourth fragment lacked homoserine and was placed at the carboxyl-terminus. The four remaining fragments, comprising half of the B chain, were tentatively assigned positions by assuming homology with bovine thrombin and with pancreatic serine proteases. Within the B chain, the active site histidine and serine were both in highly conservative regions, and an Arg-Tyr bond has been identified as a biological degradation site. Sixty-nine percent of the primary structure of human thrombin was identified by sequenator analysis. In comparing this sequence with that reported for the bovine molecule, 26 replacements are present.
Clear-cell papillary renal cell carcinoma: molecular and immunohistochemical analysis with emphasis on the von Hippel – Lindau gene and hypoxia-inducible factor pathway-related proteins

Over the past few years several investigators have independently described unique low-grade renal epithelial neoplasms with clear cytoplasm, focal to diffuse papillary architecture, and occasional leiomyomatous stromal metaplasia that are not currently recognized in the World Health Organization classification of renal tumors. These tumors have been referred to by a variety of names including clear-cell papillary renal cell carcinoma and recently "clear-cell tubulopapillary renal cell carcinoma". On the basis of the available data, such tumors are positive for cytokeratin 7 (CK7) and carbonic anhydrase IX (CA9), while being negative for CD10, α-methylacyl-CoA racemase (AMACR), and TFE3. These tumors reportedly lack trisomies of chromosomes 7 and 17, deletions of 3p25, von Hippel-Lindau (VHL) gene mutations, and VHL promoter hypermethylation. Herein, we report on nine cases of this tumor emphasizing detailed studies of the VHL gene and hypoxia-inducible factor (HIF) pathway. Molecular studies performed included VHL mutational analysis, copy number changes assessed using single-nucleotide polymorphism arrays, and qRT-PCR for VHL mRNA expression. Immunohistochemical stains for markers of HIF pathway activation (HIF-1α, CA9, and glucose transporter-1 (GLUT-1)) as well as other relevant markers (CK7, CD10, AMACR, and TFE3) were performed. None of our tumors harbored VHL gene mutations, losses of chromosomal region 3p25, or trisomies of chromosomes 7 or 17. VHL mRNA was overexpressed in our tumors relative to normal renal tissue and clear-cell renal cell carcinoma. All cases showed strong co-expression of CK7, HIF-1α, GLUT-1, and CA9. No expression of TFE3, CD10, or AMACR was seen. The morphological, immunophenotypic, and molecular features of these unique low-grade tumors are sufficiently distinct to allow separation from other renal cell carcinoma subtypes. The co-expression of CA9, HIF-1α, and GLUT-1 in the absence of VHL gene alterations in clear-cell papillary renal cell carcinoma suggests activation of the HIF pathway by non-VHL-dependent mechanisms.
Frequency of Tweeting During Presidential Debates: Effect on Debate Attitudes and Knowledge

This study examines the effects of live-tweeting during a 2012 presidential debate. We assessed the influence of sociodemographics and political and campaign characteristics on amount of tweeting during the debate, and also the effect of tweeting frequency on debate attitudes and knowledge. Results indicate that males tweeted more frequently than females, that political engagement and campaign interest were related to more debate tweeting, that campaign media use was not related to frequency of tweeting, and that political talk was marginally related to tweeting. In terms of live-tweeting effects, we found that amount of tweeting was not related to presidential debate attitudes (debate attention, enjoyment, perceived importance); however, we found individuals who tweeted most frequently learned more from the debate compared to individuals who tweeted less.
News from NIH: obesity and diabetes.

The National Institutes of Health (NIH) is engaged in several activities relevant to the theme of this journal issue, “Implementation of obesity and diabetes interventions”. This column includes brief summaries of two new strategic plans for research that were released by the NIH in early 2011. Both strategic plans include research priorities relevant to translational behavioral medicine. The NIH supports a wide range of obesity and diabetes research and so only a few examples are covered in this column. The URLs for the full strategic plans are given below.
Pathwise uniqueness for reflecting Brownian motion in certain planar Lipschitz domains

We give a simple proof that in a Lipschitz domain in two dimensions with Lipschitz constant one, there is pathwise uniqueness for the Skorokhod equation governing reflecting Brownian motion.
Redox modulation of electroosmotic flow in a carbon nanotube membrane.

Electroosmotic flow (EOF) is widely used to manipulate solutions in capillaries and microfluidic devices, and more recently in the nanotubes of a carbon nanotube membrane. In all of these applications it is important to control both the rate and direction of EOF through the system, independently of the electric field that drives EOF. For this reason, there has been considerable recent effort devoted to developing ways of modulating the rate and direction of EOF. We describe here a new method, and we use the carbon nanotube membrane (CNM) system to demonstrate this method. This new method entails coating the inside walls of the carbon nanotubes within the CNM with redox-active polymer films. The redox polymer, poly(vinylferrocene), can be reversibly electrochemically switched between an electrical neutral and a polycationic form. This provides a way for controlling both the magnitude and the sign of the surface charge on the nanotube walls, which in turn allows for control of both the rate and direction of...
Family context and gender role socialization in middle childhood: comparing girls to boys and sisters to brothers.

We studied the extent of sex-typing across different areas of child functioning (personality, interests, activities) in middle childhood as a function of the traditionality of parents' gender role attitudes and the sex composition of the sibling dyad. Participants included 200 firstborn children (mean = 10.4 years old), their secondborn siblings (mean = 7.7 years old) and their mothers and fathers. Family members were interviewed in their homes about their attitudes and personal characteristics and completed a series of seven evening telephone interviews about their daily activities. We measured children's attitudes, personality characteristics, and interests in sex-typed leisure activities (e.g., sports, handicrafts) as well as time spent in sex-typed leisure activities and household tasks (e.g., washing dishes, home repairs) and with same and opposite sex companions (i.e., parents, peers). Analyses revealed that sex-typing was most evident in children's interests and activities. Further, comparisons of girls versus boys and sisters versus brothers revealed that differences in children's sex-typing as a function of fathers' attitudes and sibling sex constellation were most apparent for children's activities. A notable exception was sex-typed peer involvement; time spent with same versus opposite sex peers was impervious to context effects. Analyses focused on children's sex-typing as a function of mothers' attitudes generally were nonsignificant.
Light Rquirements for Photoperiodic Sensitivity in Cotyledons of Dark‐grown Pharbitis nil

The light requirements for induction of flowering by a long dark period were investigated in dark-grown seedlings of Pharbitis nil Chois, cv. Violet. The cotyledons bcame photoperiodically sensitive to a 24 h dark period by two 1 min red irradiations (6.3 μmol m−2 S−1) separated by a 24 h dark period. The reversibility of the effect of brief red irradiations, and the effectiveness of low energies of red irradiation suggest the involvement of phytochrome in the induction of photoperiodic sensitivity. Partial de-etiolation occurred after these brief periods of red irradiation but the seedlings were not capable of net CO2 uptakeeven 7 h after the start of the main light period that followed the critical dark period. A changing response to the duration of the priod of darkness given between the two short red irradiations showed the the correct phasing of an endogenous photoperiodic rhythm is needed for the attainment of photoperiodic snsitivity.
Preservation of biomolecules in cancellous bone of Tyrannosaurus rex

ABSTRACT An exceptionally well preserved specimen of the tyrannosaurid dinosaur Tyrannosaurus rex Osborn shows little evidence of permineralization or other diagenetic effects. It appears that the cancellous bone tissues of the specimen may have been protected from water infiltration or mineral deposition by the very dense cortical bone which surrounds them. The cancellous tissues provided an opportunity to test the hypothesis that indigenous biomolecules might be preserved over the course of millions of years under the appropriate conditions. HPLC analysis of extracts from the bone tissues revealed the presence of molecules with light absorbance maxima consistent with nucleic acids and peptides/proteins. Analyses of bone extracts for amino acid content yielded ratios similar to those found for modern ostrich and horse bone. A high molar glycine ratio and the presence of hydroxylysine peaks in bony tissue samples from the T. rex suggests the presence of collagen type I remnants. Results indicate that the ...
Determination of Right Ventricular Ejection Fraction by Two-Dimensional Echocardiographic Single Plane Subtraction Method

Right ventricular ejection fraction is a useful measurement for evaluating right ventricular function in various states, including coronary artery disease, chronic obstructive pulmonary disease, and both congenital and valvular heart diseases. The right ventricular geometry has made it difficult to evaluate right ventricular ejection fraction by simple Echocardiographic methods. In this study 36 consecutive patients were examined by two-dimensional echocardiography within 4 hours of radionuclide-determined right ventricular ejection fraction to test a simplified method for calculating right ventricular ejection fraction by two-dimensional echocardiography. Echocardiographic measurements were independently determined in the subcostal and apical four-chamber views. Correlation with first pass radionuclide right ventricular ejection fraction was r=0.89 and 0.84. Right ventricular ejection fraction could be calculated from one of two views in 92% of patients studied. This technique for determination of right ventricular ejection fraction offers a simple noninvasive method of evaluating right ventricular function.
Transition from Heavy to Light Tails in Retransmission Durations

Retransmissions serve as the basic building block that communication protocols use to achieve reliable data transfer. Until recently, the number of retransmissions were thought to follow a light tailed (in particular, a geometric) distribution. However, recent work seems to suggest that when the distribution of the packets have infinite support, retransmission-based protocols may result in heavy tailed delays and even possibly zero throughput. While this result is true even when the distribution of packet sizes are light-tailed, it requires the assumption that the packet sizes have infinite support. However, in reality, packet sizes are often bounded by the Maximum Transmission Unit (MTU), and thus the aforementioned result merits a deeper investigation. To that end, in this paper, we allow the distribution of the packet size L to have finite support. This packet is sent over an on-off channel {(A_i,U_i)} with alternating available A_i and unavailable U_i periods. If L&#8805;A_i, the transmission fails and we wait for the next period A_(i+1) to retransmit the packet. The transmission duration is thus measured from the first attempt to a point when a channel available period larger than L. Under mild conditions, we show that the transmission duration distribution exhibits a transition from a power law main body to an exponential tail with Weibull type distributions between the two. The time scale to observe the power law main body is roughly equal to the average transmission duration of the longest packet. Both the power law main body and the exponential tail could dominate the overall performance. For example, the power law main body, if significant, may cause the channel throughput to be very close to zero. On the other hand, the exponential tail, if more evident, may imply that the system operates in a benign environment. These theoretical findings provide an understanding on why some empirical measurements suggest heavy tails and light tails for others (e.g., wireless networks). We use these results to further highlight the engineering implications from distributions with power law main bodies and light tails by analyzing two cases: (1) The throughput of on-off channels with retransmissions, where we show that even when packet sizes have small means and bounded support the variability in their sizes can greatly impact system performance. (2) The distribution of the number of jobs in an M/M/&#8734; queue with server failures. Here we show that retransmissions can cause long-range dependence and quantify the impact of the maximum job sizes on the long-range dependence.
The Paradox of Administrative Control in Fostering Teacher Professional Development.

Abstract In this case study, we use a consensus model as a framework for examining the professional development component of a standards-based reform effort initiated by a school district in the United States. We describe the district's actions, analyze the extent of adherence to the model, and identify reasons for what occurred. Although administrators intended to adopt key design principles of effective professional development, specific implementation strategies undermined and contradicted these principles. Their response to increasing bureaucratic controls at the state and national levels translated into increased regulation and control at the district and school levels, which paradoxically restricted the very attributes they sought to enhance.
Development of neuronal specificity in retinal ganglion cells ofXenopus

Summary Retinal ganglion cells of Xenopus form topographically organized connections with the optic tectum between larval stages 35 and 40. However, the position at which each retinal ganglion cell connects in the tectum is already fully specified at larval stage 31, before visible differentiation of ganglion cells and before outgrowth of their axons. This was shown by 180-degree rotation of the eyecup of Xenopus larvae at stages 28–35. After metamorphosis of these animals, the projection from the rotated eye to the optic tectum was mapped electrophysiologically, and compared with the normal retinotectal map. Normal retinotectal connections were formed after rotation of the eyecup before stage 30. Eye rotation at stage 30 resulted in reversal of the retinotectal map in the AP axis, but not in the DV axis of the retina. Rotation of the eye after stage 30 resulted in total rotation of the retinotectal map. Specification of the central connections of retinal ganglion cells occurs over a period of about 10 hours, in two steps related to the relative positions of the ganglion cells in the AP and DV axes of the retina. The hypothesis is advanced of stepwise specification of progressively finer details of the pattern of neuronal connections; the initial steps occurring at an early stage of neuroblast differentiation before the outgrowth of neuronal processes.
Evidence against recessive inheritance of susceptibility to the chronic carrier state for hepatitis B antigen.

THE discovery of Australia antigen (Au), now designated hepatitis B antigen (HBAg), and its association with type B viral hepatitis stimulated application of a variety of serological assays for the detection of HBAg and anti-HBAg in pretransfusion screening of donors' blood and epidemiological work relating to transmission of hepatitis1–6. The reasons for chronic prevalence of HBAg in apparently healthy carriers, who form an epidemiological reservoir of hepatitis B virus (HBV), remain ill-defined. Based on family studies with HBAg, Blumberg et al proposed a hypothesis that the persistence of HBAg for long periods is evidence of a genetic susceptibility which is inherited as a simple recessive trait7,8. The extensive family data, however, included no pedigree with progeny of two parents positive for the antigen. Such a family is crucial to lend validity to the genetical hypothesis. An independent study in Italy supported the hypothesis with certain qualifications9.
Mediators of C5a-induced bronchoconstriction.

Previous studies had suggested that histamine and products of arachidonate metabolism were mediators of the bronchoconstriction induced in guinea pigs by the complement cleavage product C5a. The present study was conducted to further define the arachidonate metabolite(s) involved. Tracheal airflow and transpulmonary pressure were measured in anesthetized and artificially ventilated guinea pigs and pulmonary resistance and dynamic lung compliance were calculated as a measure of bronchoconstriction. The effect of the peptido-leukotriene antagonist L-649,923 and the thromboxane synthetase inhibitor U-63557A on the C5a-induced bronchoconstriction was determined. Also, the response to C5a was evaluated in animals made tachyphylactic to the bronchoconstrictor actions of LTB4. C5a-induced bronchoconstriction was not altered in animals treated with L-649,923 or made tachyphylactic to LTB4 suggesting that LTB4 and peptido-leukotrienes are not major mediators of the response. C5a challenge caused a significant increase in plasma thromboxane B2 levels which was prevented in part by the thromboxane synthetase inhibitor U-63557A. In addition, C5a-induced bronchonconstriction was significantly inhibited by U-63557A. Thus, these studies suggest that thromboxane is the arachidonate metabolite at least in part responsible for C5a-induced bronchoconstriction.
Minimum Distance Estimators for Location and Goodness of Fit

Abstract A weighted Cramer-von Mises distance between the empirical distribution function and the assumed model F0(x - θ) is minimized to produce estimators θ n that are asymptotically normal. If the weight function is taken proportional to (- ln f 0)″/f 0 , then θ n is asymptotically efficient and the minimized distance has the appropriate loss of one degree of freedom. Special attention is focused on the limiting distribution of this latter goodness-of-fit statistic in both null and alternative situations.
Direct phosphorylation of brain tyrosine hydroxylase by cyclic AMP-dependent protein kinase: mechanism of enzyme activation.

Abstract Tyrosine hydroxylase [tyrosine monooxygenase, L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2] was highly purified from rat caudate nuclei. When the pure hydroxylase was phosphorylated by incubation with cyclic AMP-dependent protein kinase and [32P]ATP, 32P and tyrosine hydroxylase activity were detected after polyacrylamide gel electrophoresis in a single protein band. After sodium dodecyl sulfate gel electrophoresis, 32P was detected only in a probably active subunit of tyrosine hydroxylase of molecular weight 62,000. Phosphorylation of the hydroxylase increased its activity by 2-fold, and was associated with an increase in Vm without any change in Km for either substrate or cofactor. We propose that the pool of native tyrosine hydroxylase is composed of a mixture of enzyme molecules in both active and probably inactive forms, that the active form is phosphorylated, and that phosphorylation produces an active form of the enzyme at the expense of an inactive one.
Glucocorticoid receptors in the mammalian inner ear: RU 28362 binding sites.

Abstract The effects of glucocorticoid hormones are thought to be initiated by binding of the steroid to stereospecific intracellular receptor proteins in target tissues. The synthetic glucocorticoid [3H]-RU 28362, which demonstrates negligible affinity for mineralocorticoid (Type I) receptors [Philibert et al., (1983) Endocrine Soc. Abstr. 65, 335], was employed to identify the high-affinity glucocorticoid (Type II) receptors in the inner ear. By Scatchard analysis, the Kd of the [3H]-RU 28362-cytoplasmic receptor complex was 11.4 × 10−9 M for the lateral wall of the basal turn of the cochlea and 12.7 × 10−9 M for the ampullae of the semicircular canals. The concentration of binding sites, Bmax, was 240 fmol/mg dry tissue for the cochlear specimen and 89 fmol/mg dry tissue for the ampullae. Time course studies indicated that the binding of [3H]-RU 28362 by inner ear tissues reached equilibrium within 30 min of incubation at 25°C. Based on the total specific binding measured with [3H]-RU 28362, the glucocorticoid receptor concentration in the lateral wall of the basal turn of the cochlea appears to exceed that in the ampullae of the semicircular canal by a factor of 2.7. Substantial specific [3H]-RU 28362 binding to the cochlear lateral wall and ampullar tissue suggests the presence of glucocorticoid receptors and sites of glucocorticoid action in the inner ear.
Juvenile firesetting: Assessment and treatment in psychiatric hospitalization and residential placement

Although the phenomenon of juvenile firesetting has been well described, little has been written about the treatment of the firesetter during in-patient psychiatric hospitalization or residential placement. This paper describes a treatment program for children with firesetting behavior developed and implemented on a children's psychiatric unit in a general hospital. The program consists of three components: assessment, didactic phase, and practice, and it incorporates educational as well as behavior modification principles.
Accuracy of clinical assessment of paravaginal defects in women with anterior vaginal wall prolapse.

Abstract Objective: The objective of this study was to determine the accuracy of clinical assessment of paravaginal defects in women with anterior vaginal wall prolapse. Study Design: A retrospective chart review of all women undergoing surgery for anterior vaginal wall prolapse during the years of 1994 to 1996 identified operative notes that described the surgical assessment of paravaginal support. These surgical findings were compared with the preoperative clinical assessment. Clinical parameters that predicted poor correlation were identified. Statistical analysis used the χ 2 test. Results: One hundred seventeen patients had surgery for anterior vaginal prolapse. Seventy had documentation of an intraoperative paravaginal support evaluation. Of these, 44 patients had vaginal procedures, and 26 had abdominal procedures. All patients had at least stage 2 prolapse before surgery, and all were noted to have excellent pelvic support 4 to 6 weeks after surgery. The prevalence of paravaginal defects at surgery was 47% on the right and 41% on the left. The sensitivity and negative predictive value for the clinical assessment for paravaginal defects were good on both the right and left sides, whereas the specificity and positive predictive values were poor. Stage of prolapse, previous hysterectomy, or previous anterior colporrhaphy did not significantly affect the accuracy of the clinical examination in predicting fascial defects. However, previous retropubic urethropexy did significantly decrease the accuracy of the clinical examination in predicting right paravaginal defects ( P Conclusion: Although preoperative clinical assessment for paravaginal defects is useful, it does not substitute for careful intraoperative evaluation for endopelvic fascial defects. (Am J Obstet Gynecol 1999;181:87-90.)
Predictive value of prominent pulmonary arterial wedge V waves in assessing the presence and severity of mitral regurgitation

Indwelling pulmonary arterial catheters are often used to monitor and to guide therapy in critically ill patients. The magnitude of the V wave recorded from the pulmonary arterial wedge (PAW) position is sometimes used to assess the presence and severity of mitral regurgitation (MR). The present study was performed to assess the relation (or lack thereof) between a "prominent" PAW V wave and qualitative and quantitative estimates of MR. In 903 subjects (445 men and 458 women, aged 49 +/- 13 [mean +/- SD] years) referred for cardiac catheterization, an oximetrically confirmed PAW pressure was recorded with a large-lumen stiff catheter, and a left ventriculogram was recorded. In 646 of these subjects (328 men and 318 women, aged 50 +/- 13 years), forward cardiac output was measured by the Fick principle, and a regurgitant fraction was calculated. Prominent PAW V waves--as defined in several ways--were insensitive and had poor positive predictive value in identifying moderate or severe MR. At the same time, the absence of prominent PAW V waves was relatively specific for the absence of moderate or severe MR, and the negative predictive value of small V waves was very good. Thus, the prominence of a PAW V wave cannot be used to assess the presence or severity of MR.
Modifying dew-retted flax fibers and yarns with a secondary enzymatic treatment

Preliminary studies by atomization test the application of various kinds of enzymes as a means of tailoring dew-retted flax fibers in a low moisture atmosphere. A series of chemical and physical tests determines the effect of enzymes on fibers and blended yarns (50:50 flax : cotton). GLC analysis of post-treatment fiber washes shows that lipase and cellulase release the most sugars, likely due to structural disorganization of the fiber matrix. Glucose is the sugar most released by enzyme treatment. Mid-infrared spectroscopy of fibers indicates the loss of carbohydrates and the presence of absorbed proteins following all enzyme treatments. All treatments reduce fiber strength and elongation compared to untreated fibers, with cellulase reducing fiber strength the most at 56% of the untreated control. Treatments reduce the occurrence of thick and thin places but reduce yarn strength as well. In general, lipase and arabinanase treatments influence yarn properties the most by increasing strength over the buffer-only treatment, increasing elongation over untreated and buffer-treated yarns, and reducing neps and thick/thin places. These preliminary results suggest strategies to optimize enzyme treatments for improved textile properties.
A phase transformation study in the BaO · Al2O3 · 2SiO2 (BAS)–Si3N4 system

A phase transformation study was carried out with barium aluminosilicate (BAS) forming powders (BaCO3, Al2O3, and SiO2) in a BAS-Si3N4 system. Powders were heat-treated in air at 1 atm pressure at different temperatures from 600 to 1150 °C at an interval of 50 °C to study the phase transformations during the formation of BAS. The phase transformations of α to β-Si3N4 is studied by heat-treating the powders at 1600 °C for different sintering times in a nitrogen environment at 1 atm pressure. Formation of different phases was identified by using powder x-ray diffraction. Formation of different forms of barium silicates occurs as an intermediate step between 650 and 950 °C and hexagonal BAS forms between 900 and 950 °C. The hexagonal form of BAS always forms first and persists as a metastable phase in the composites with no evidence of the monoclinic phase. An attempt made to fully transform hexagonal BAS to monoclinic BAS by using LiF as a mineralizer proved to be successful. The hexagonal form of BAS forms first when heat-treated at 1000 °C and is fully transformed to monoclinic BAS when heat-treated at 1100 °C.
Exposure of Japanese Quail and Parakeets to the Pyrolysis Products of Fry Pans Coated with Teflon® and Common Cooking Oils

apanese quail and parakeets were exposed to the pyrolysis products of: (1) commercial fry pans coated with Teflon® finish, (2) plastic fry pan handles, (3) corn oil, and (4) butter. Other materials used in the test were commercial aluminum fry pans and cast iron fry pans. A four-hour Approximate Lethal Temperature (ALT) was determined for each test material for each specie. All products tested were lethal to Japanese quail with ALT's ranging from 260° C for butter in cast iron to 370 °C for a plastic handle in a glass container. The ALT for a fry pan coated with Teflon® finish was 330°C. All products were also lethal to parakeets with ALT's of 260°C for both the pan coated with Teflon® finish plus butter and the cast iron pan plus butter. The ALT for a fry pan coated with Teflon® finish was 280°C.