cssi/SciSciGPT-SciSciNet huggingface dataset:
Socio-economic status and high-school friendship choice: Elmtown's youth revisited

Abstract Whereas Hollingshead's 1942 study of Elmtown High found socio-economic status homophily to be a prime criterion in students' friendship and dating choices, the present study, a secondary analysis of James Coleman's 1958 Elmtown data, finds socio-economic status homophily unimportant for friendship and dating choices. This decline in status homophily occurred at a time when class distinctions were becoming blurred in Elmtown and the “rating-and-dating” system was losing in national importance. Status homophily is not a constant, but a variable: clear class distinctions facilitate status homophily, while shifting class and occupational systems make for class-heterogeneous social networks.
Blessed are the pacemakers.

Many neurons, particularly inhibitory neurons in motor areas, express ion channels that cause them to fire rapidly and regularly without input. A paper now presents evidence that an inherited ataxia due to mutation in a P/Q-type calcium channel gene results from compromised pacemaking in cerebellar Purkinje neurons, suggesting a possible therapy.
Prevention of rheumatic fever.

Abstract The incidence both of first attacks of rheumatic fever and of recurrences of the disease in patients who have had one or more attacks can be greatly reduced. Early adequate treatment of streptococcal infections definitely can reduce the incidence of rheumatic fever. When rheumatic fever does occur, following the eradication of the group A streptococcus by an adequate course of penicillin therapy, recurrent attacks can be prevented in most instances by the continuous administration of any one of several antibacterial drugs. It is to be hoped that ultimately a more biologic method of preventing streptococcal infections and acute rheumatic fever will be available. However, until this does occur, the current available methods of treating and preventing streptococcal infection can greatly reduce the incidence of rheumatic fever and of recurrences of the disease.
Comparison of the effect of prolactin on dopamine release from the rat dorsal and ventral striatum and from the mediobasal hypothalamus superfused in vitro.

Abstract In this paper, by means of a superfusion technique, we have examined the effect of ovine prolactin on dopaminergic neurons innervating the dorsal striatum, ventral striatum and the mediobasal hypothalamus of male rats. Fragments from dorsal striatum were superfused with ovine prolactin dissolved in normal medium (Krebs-Ringer phosphate) or medium containing tetrodotoxin (TTX, 10 −6 M). Ovine prolactin stimulated the in vitro release of dopamine from dorsal and ventral striatal fragments. In dorsal striatal fragments a linear dose-dependent dopamine release was observed only when fragments were superfused with Krebs-Ringer phosphate-TTX medium. In addition, [Leu 5 ]enkephalin (10 −6 and 10 −5 M) decreased the prolactin-induced in vitro dopamine release from dorsal striatal fragments superfused with Krebs-Ringer phosphate-TTX medium. Ovine prolactin (10 −9 –10 −5 M) did not elicit changes in dopamine, 3,4-dihydroxyphenylacetic acid or 5-hydroxyindoleacetic acid outputs from mediobasal hypothalamic fragments superfused with Krebs-Ringer phosphate medium containing TTX. The possible regulatory mechanisms of ovine prolactin on dopaminergic neurons are discussed.
Distributed systems of self-reconfiguring robots

A robot designed for a single purpose can perform a specific task very well, but it may perform poorly on a different task, or in a different environment. This is acceptable if the environment is structured; however, if the task is in an unknown environment, then a robot with the ability to change shape to suit the environment and the required functionality will be more likely to succeed. We wish to create more versatile robots by using self-reconfiguration: hundreds of small modules will autonomously organize and reorganize as geometric structures to best fit the terrain on which the robot has to move, the shape of the object the robot has to manipulate, or the sensing needs for the given task. For example, a robot could synthesize a snake shape to travel through a narrow tunnel, and then morph into a six-legged insect to navigate on rough terrain upon exit.
Regressograms and Mean-Covariance Models for Incomplete Longitudinal Data

Longitudinal studies are prevalent in biological and social sciences where subjects are measured repeatedly over time. Modeling the correlations and handling missing data are among the most challenging problems in analyzing such data. There are various methods for handling missing data, but data-based and graphical methods for modeling the covariance matrix of longitudinal data are relatively new. We adopt an approach based on the modified Cholesky decomposition of the covariance matrix which handles both challenges. It amounts to formulating parametric models for the regression coefficients of the conditional mean and variance of each measurement given its predecessors. We demonstrate the roles of profile plots and regressograms in formulating joint mean-covariance models for incomplete longitudinal data. Applying these graphical tools to the Fruit Fly Mortality (FFM) data, which has 22% missing values, reveals a logistic curve for the mean function and two different models for the two factors of the mod...
Glycosylation of low density lipoprotein in patients with type 1 (insulin-dependent) diabetes: correlations with other parameters of glycaemic control.

Glycosylation of low density lipoproteins obtained from 16 patients with Type 1 (insulin-dependent) diabetes and from 16 age-, sex-, and race-matched controls, was determined. The diabetic patients were normolipaemic and were in good or fair glycaemic control. Eleven patients performed home blood glucose monitoring. Glycosylation of low density lipoproteins in the diabetic patients was significantly higher (p < 0.001) than in the control subjects, and was significantly correlated with haemoglobin A1c, (p < 0.01), glycosylation of plasma proteins, (p < 0.001), and mean home blood glucose, (p < 0.01). This study confirms that, in diabetic patients, increased glycosylation of low density lipoprotein occurs to an extent which correlates closely with other commonly used indices of glycaemic control.
The Bottlenose Dolphin: Biology and Conservation

"This excellent introduction on the biology of the bottlenose dolphin also provides a review of conservation issues and outlines current knowledge of dolphins in general. . . . for students, professionals, and anyone interested in the bottlenose dolphin."--Charles W. Potter, National Museum of Natural History"The Bottlenose Dolphin"presents for the first time a comprehensive, colorfully illustrated, and concise overview of a species that has fascinated humans for at least 3,000 years.After reviewing historical myths and legends of the dolphin back to the ancient Greeks and discussing current human attitudes and interactions, the author replaces myths with facts--up-to-date scientific assessment of dolphin evolution, behavior, ecology, morphology, reproduction, and genetics--while also tackling the difficult issues of dolphin conservation and management.Although comprehensive enough to be of great value to professionals, educators, and students, the book is written in a manner that all dolphin lovers will enjoy. Randall Wells s anecdotes interspersed throughout the work offer a first-hand view of dolphin encounters and research based on three decades working with them. Color photographs and nearly 100 black and white illustrations, including many by "National Geographic"photographer Flip Nicklin, beautifully enhance the text. Readers of "The Bottlenose Dolphin"will better appreciate what dolphins truly are and do, as well as understand some of the controversies surrounding them. While raising compelling questions, the book provides a wealth of information on a legendary species that is loved and admired by many people.John E. Reynolds, professor of marine science at Eckerd College, St. Petersburg, Florida, is chair of the U.S. Marine Mammal Commission. He has written over 100 articles on marine mammal biology and conservation and is coauthor with Daniel K. Odell of "Manatees and Dugongs"and coeditor of "Biology of Marine Mammals."Randall S. Wells is a behavioral ecologist with the Conservation Biology Department of the Chicago Zoological Society and adjunct associate professor of ocean sciences at the University of California, Santa Cruz. He also serves as director of the Center for Marine Mammal and Sea Turtle Research at Mote Marine Laboratory, Sarasota, Florida, where he conducts the world s longest running study of wild dolphins.Samantha D. Eide, a graduate student at the University of South Florida, is field leader for the Eckerd College Dolphin Project, St. Petersburg, Florida."
Genotypic and Environmental Effects on Grain Yield and Quality of Oat Grown in North Dakota

The grain yield and quality determine much of the value of an oat (A vena saliva L.) crop to the producer. This study investigated effects of genotype and environment on grain yield and quality. Twelve oat genotypes were grown during 3 yr at four locations in North Dakota where detailed environmental data were being collected. Grain yield, test weight, groat percentage, groat weight, and groat composition (protein, oil, β-glucan, and starch concentrations) were evaluated. Results were subjected to analysis of variance and influences of environmental factors were evaluated by correlation analysis. Analysis of variance suggested that grain yield, groat starch, and ash concentrations were more strongly affected by environment than by genotype. Test weight, groat percentage, groat weight, protein, and β-glucan were about equally influenced by environment and by genotype, whereas groat lipid was more strongly influenced by genotype. Significant environment x genotype interactions for all characteristics were attributed to differential resistance of genotypes to crown rust (caused by Puccinia coronata Corda var. aveneae W.P. Fraser & Ledingham) infection. Environments severely affected by crown rust produced grain with lower test weight, groat weight, and groat percentage in susceptible genotypes. Correlation analyses suggested that warm, bright (high solar radiation) spring weather, and cooler summer weather without excessive rains during grain filling generated the best oat yields with high quality grain.
Weight Reduction and Cardiovascular and Metabolic Disease Prevention: Clinical Trial Update

In children and adults, weight gain is accompanied by the early and more aggressive manifestations of well-recognized risk factors for atherosclerotic cardiovascular disease (CVD). Because insulin resistance and the later development of type 2 diabetes mellitus also accompany weight gain, the term cardiometabolic risk is now commonly used to describe this emerging global health problem. Weight loss will improve cardiometabolic risk. However, less is known about the effect of weight loss on the development of disease and, most importantly, type 2 diabetes and CVD outcomes in the form of death, myocardial infarction, and stroke. This review describes current clinical research that uses health-promoting lifestyle interventions, new drugs, and even surgery, which are all aimed at weight loss, reduction in disease manifestations, and improved outcomes. These anticipated data are essential for the future development of effective CVD prevention strategies. Results are awaited with great interest.
β1 integrins isolated from embryonic chicken fibroblasts bind to monomers and polymers of type I collagen

The avian integrin beta 1 subfamily consists of multiple alpha-beta subunit heterodimers. We employed two different physical states of type I collagen, monomers and fibrils, in the isolation and characterization of avian collagen integrins. Affinity chromatography showed that three integrins, tentatively designated alpha 155 beta 1 (band 1), alpha 5a beta 1, and alpha 3 beta 1 (band 2), bind fibrillar and monomeric collagen under physiological ionic conditions and require divalent cations for binding activity. Sodium chloride gradients (0-0.5 M) were used to assess the functional ability of the integrins to remain bound to the two forms of type I collagen. The results show that integrins elute from the two forms of collagen with distinct fractionation profiles. One integrin, alpha 155 beta 1, binds fibrillar collagen with relatively higher affinity than the other beta 1 receptors. This same avian integrin, alpha 155 beta 1, is immunoreactive with an antiserum (Hynes et al., 1989) raised against a peptide that corresponds to the entire alpha 5 cytoplasmic domain, and coincidently, part of the alpha 6 cytoplasmic domain (de Curtis et al., 1991). Cell biological studies employing double immunofluorescence show that integrins recognized by this antiserum co-localize with extracellular deposits of type I collagen.
Dynamics of cellular entry and drug delivery by dendritic polymers into human lung epithelial carcinoma cells

Dendrimers and hyperbranched polymers are emerging as potentially ideal drug delivery vehicles because they provide a significant amount of tailorability and a large density of functional groups. This study explores the dynamics of cellular entry of dendrimers and hyperbranched polymers alone, and in the complexed form with ibuprofen, into A549 human lung epithelial carcinoma cells using UV/Vis spectroscopy, flow cytometry and fluorescence microscopy. Both dendrimers and hyperbranched polymers appear to enter these cells rapidly. The polyamidoamine (PAMAM) dendrimers, with NH2 and OH end functionalities appear to enter cells (in approx. 1 h) faster than the hyperbranched polyol (OH functionality) (in approx. 2 h). Cellular entry of PAMAM-NH2 was detected as early as 5 min. All branched polymers and their ibuprofen complexes entered A549 lung epithelial cells rapidly when compared to the pure drug. The drug payload was about 50% by weight in the complexes formed by PAMAM-NH2 dendrimers and was about 30% in the encapsulated form for Polyol-OH and PAMAM-OH. The complexation and encapsulation of ibuprofen with the polymers appear to facilitate rapid cellular entry of ibuprofen. The anti-inflammatory effect of the polymer-complexed drug was demonstrated by more rapid suppression of COX-2 mRNA levels than that achieved by the pure drug. This suggests that these dendritic polymers can act as efficient drug carriers, delivering high 'payloads' of drug even with complexation and encapsulation.
On P vs. NP and geometric complexity theory: Dedicated to Sri Ramakrishna

This article gives an overview of the geometric complexity theory (GCT) approach towards the P vs. NP and related problems focusing on its main complexity theoretic results. These are: (1) two concrete lower bounds, which are currently the best known lower bounds in the context of the P vs. NC and permanent vs. determinant problems, (2) the Flip Theorem, which formalizes the self-referential paradox in the P vs. NP problem, and (3) the Decomposition Theorem, which decomposes the arithmetic P vs. NP and permanent vs. determinant problems into subproblems without self-referential difficulty, consisting of positivity hypotheses in algebraic geometry and representation theory and easier hardness hypotheses.
Evaluation of Dimensionality-reduction Methods from Peptide Folding-unfolding Simulations.

Dimensionality reduction methods have been widely used to study the free energy landscapes and low-free energy pathways of molecular systems. It was shown that the non-linear dimensionality-reduction methods gave better embedding results than the linear methods, such as principal component analysis, in some simple systems. In this study, we have evaluated several non linear methods, locally linear embedding, Isomap, and diffusion maps, as well as principal component analysis from the equilibrium folding/unfolding trajectory of the second β–hairpin of the B1 domain of streptococcal protein G. The CHARMM parm19 polar hydrogen potential function was used. A series of criteria which reflects different aspects of the embedding qualities were employed in the evaluation. Our results show that principal component analysis is not worse than the non-linear ones on this complex system. There is no clear winner in all aspects of the evaluation. Each dimensionality-reduction method has its limitations in a certain aspect. We emphasize that a fair, informative assessment of an embedding result requires a combination of multiple evaluation criteria rather than any single one. Caution should be used when dimensionality-reduction methods are employed, especially when only a few of top embedding dimensions are used to describe the free energy landscape.
Clinical prediction rule for respiratory isolation of patients with suspected pulmonary tuberculosis

Abstract The aim of this study was to develop a weighted clinical prediction model for isolating patients with suspected pulmonary tuberculosis (PTB). We conducted a retrospective case control study in which all patients placed on respiratory isolation for suspected PTB from January 1997 to December 2006 were identified. During this 10-year period, 6957 patients were placed in respiratory isolation, 132 of which were diagnosed with PTB. A representative sample was randomly chosen from the group of patients placed in respiratory isolation but with negative Mycobacterium tuberculosis (MTB) cultures (PTB-nonPTB, 1:4 ratio). These 528 patients along with the 132 patients with positive culture for MTB were included in this study. In multivariate analysis, African American race, history of active tuberculosis (TB), history of positive tuberculin skin testing, TB exposure, weight loss, malaise, night sweats, purulent sputum, positive tuberculin skin testing during hospitalization, white blood cell between 4 and 10,000, upper lobe disease on chest x-rays (CXR), and thoracic computed tomography scans were statistically significantly associated with PTB. Age, human immunodeficiency virus-positive status, and white blood cell count greater than 10,000 were negative predictors. A scoring system was developed using these variables. A patient's score of 4 or higher indicated a need for respiratory isolation, predicting a culture positive for MTB (99% sensitivity; 33.7% specificity). If the prediction model was used for determining isolation for TB at the time of admission, 2734 episodes of isolation could have been avoided during the 10-year study period.
AN EXAMINATION OF ADULT ONSET OFFENDING

Abstract The onset of offending received much research attention in criminology; however, the majority of research focused on juvenile offenders. As a consequence, little was known about the prevalence of and causes associated with adult onset. Using data from the Philadelphia portion of the National Collaborative Perinatal Project followed through the mid- to late thirties, this study focused on the prevalence of adult onset and the factors related to adult onset. Three key findings emerged from this study. First, females were less likely than males to be adult onset offenders. Second, participants who had mothers that smoked cigarettes during pregnancy were more likely to be adult onset offenders. Third, participants who had higher scores on the total battery score of the California Achievement Test (CAT) were less likely to be adult onset offenders. Limitations and future research directions are outlined.
Proteolytic digestion of alpha-lactalbumin: physiological implications.

The kinetics of the partial digestion of bovine alpha-lactalbumin (alpha-LA) by trypsin, alpha-chymotrypsin, and pepsin was monitored by lactose synthase activity, HPLC, and difference spectrophotometry. The relative stabilities of the various metal-bound states of alpha-LA to trypsin and chymotrypsin at 37 and 5 degrees C decrease in the following order: Ca(II)-alpha-LA greater than Zn(II), Ca(II)-alpha-LA greater than apo-alpha-LA. The HPLC digestion patterns of Ca(II)-alpha-LA and Zn(II), Ca(II)-alpha-LA at 5 and 37 degrees C were similar, while the corresponding digestion patterns for apo-alpha-LA were quite different, reflecting the existence of the thermally induced denaturation states of apo-alpha-LA within this temperature region. Occupation of the first Zn(II)-binding site in Ca(II)-loaded alpha-LA slightly alters the HPLC digestion patterns at both temperatures and accelerates the digestion at 37 degrees C due to Zn(II)-induced shift of the thermal transition of alpha-LA, exposing some portion of thermally denatured protein. The results suggest that the binding of Zn(II) to the first Zn(II)- (or Cu(II)-specific site does not cause any drastic changes in the overall structure of alpha-LA. The acidic form of alpha-LA (at pH 2.2 and 37 degrees C) was digested by pepsin at rates similar to that for the apo- or Cu(II), Ca(II)-loaded forms by trypsin or alpha-chymotrypsin at neutral pH. Complexation of alpha-LA with bis-ANS affords protection against pepsin cleavage. It is suggested that the protective effects of similar small lipophilic compounds to alpha-LA may have physiological significance (e.g., for nutritional transport).
Negative-Pion Activation of Silver

The yields of some isotopes of palladium, rhodium, and ruthenium produced by the reaction of ${\ensuremath{\pi}}^{\ensuremath{-}}$ mesons with silver were determined radiochemically. These results, together with those from a similar study with bromine, make possible a comparison with the data obtained with photographic plates. The results are consistent with each other within the uncertainties of the experimental data.
29.1: Invited Paper: High‐Resolution Monitors: What Does it Take?

The high resolution and high image content computer monitors become more realistic with TFT-LCD technology. IBM made a big step forward recently with 22 inch diagonal 9.2 million pixel (204 ppi) Amorphous Silicon TFT-LCD. This document covers direct view high resolution monitor requirements, manufacturing technologies and its applications, today and in the near future, based on the prototype.
Acción Organizacional y Socioconstruccionismo

In this paper, it is discussed the notion of “prospective rationality”, the concept most diseminated around the idea of organization in our country. At the same time, it is inquired the introduction of social dispositives, administrative tools and agreements that are generated in foreign cultures and inserted in our culture with no reflection. Finally, a new understanding for the organization is proposed through the construccionism, that is positioned not only as a theory but also as a metodological tool able to generate new interpretations to improve local ways of life.
PREVENTION OF THE EMERGENCE OF ANTIBIOTIC-RESISTANT STRAINS OF BACTERIA BY ATABRINE.

Abstract In addition to spermine and spermidine, atabrine has been found to prevent effectively the emergence of strains resistant to streptomycin, sulfathiazole, novobiocin, erythromycin, tetracycline, penicillin, and chloramphenicol. Since atabrine already has been used widely in medical practice, we believe that it can now be incorporated into antibiotic therapy to prevent the emergence of resistant strains of bacteria. These findings are suggestive also of their possible application in early cancerous and viral systems.
Effects of local mRNA structure on posttranscriptional gene silencing

Antisense oligodeoxynucleotides (AONs) and short interfering RNAs (siRNAs) effect posttranscriptional gene silencing (PTGS) by hybridizing to an mRNA and then directing its cleavage. To understand the constraints that mRNA structure imposes on AON- vs. siRNA-mediated PTGS, AON- and siRNA-mediated cleavage of defined mRNA structures was monitored in Drosophila embryo whole-cell lysates. We observed that AON-directed cleavage was ≈3-fold faster than cleavage with a siRNA directed to the same target site. Furthermore, and unexpectedly, AON-mediated cleavage was found to be much less fastidious with respect to target sequence accessibility, as measured by the presence of unpaired nucleotides, than a corresponding siRNA. Nonetheless, in vivo, siRNAs silenced their mRNA target at least 2-fold more efficiently than the corresponding AON. These seemingly contradictory results suggested that additional, as yet undefined factors play an important role in regulating PTGS efficiency in vivo. We used a well defined RNA-binding protein, αCP, and its corresponding high-affinity RNA-binding site to explore this hypothesis. We found that prebound αCP effectively blocked AON-mediated cleavage of the RNA-binding site compared with cleavage of the site in the absence of αCP. We conclude that higher-order structures formed by RNA and bound proteins play an important role in determining the efficiency of AON-directed PTGS. We hypothesize that strategies aimed at removing RNA-binding proteins might significantly improve AON-mediated PTGS in vivo.
Opportunities and challenges in integrating electronic health records into undergraduate medical education: a national survey of clerkship directors.

Background: Few studies have reported on the utilization and the effect of electronic health records on the education of medical students. Purpose: The purpose of this study was to describe the current use of electronic health records by medical students in the United States and explore the opportunities and challenges of integrating electronic health records into daily teaching of medical students. Methods: A survey with 24 questions regarding the use of electronic health records by medical students was developed by the Alliance for Clinical Educators and sent to clerkship directors across the United States. Both quantitative and qualitative responses were collected and analyzed to determine current access to and use of electronic health records by medical students. Results: This study found that an estimated 64% of programs currently allow student use of electronic health records, of which only two thirds allowed students to write notes within the electronic record. Overall, clerkship directors’ opinion...
Iron dysregulation in movement disorders

Iron is an essential element necessary for energy production, DNA and neurotransmitter synthesis, myelination and phospholipid metabolism. Neurodegeneration with brain iron accumulation (NBIA) involves several genetic disorders, two of which, aceruloplasminemia and neuroferritinopathy, are caused by mutations in genes directly involved in iron metabolic pathway, and others, such as pantothenate-kinase 2, phospholipase-A2 and fatty acid 2-hydroxylase associated neurodegeneration, are caused by mutations in genes coding for proteins involved in phospholipid metabolism. Phospholipids are major constituents of myelin and iron accumulation has been linked to myelin derangements. Another group of NBIAs is caused by mutations in lysosomal enzymes or transporters such as ATP13A2, mucolipin-1 and possibly also β-galactosidase and α-fucosidase. Increased cellular iron uptake in these diseases may be caused by impaired recycling of iron which normally involves lysosomes. Abnormal iron utilization by mitochondria, as has been proposed in Friedreich's ataxia, is another possible mechanism of iron accumulation. Other, more common degenerative movement disorders, such as Parkinson's disease, Huntington's disease, multiple system atrophy and progressive supranuclear palsy also exhibit increased brain iron content. Finally, brain iron deficiency has been implicated in restless legs syndrome. This review provides an update on recent findings related to genetics, pathogenic mechanisms, diagnosis, and treatment of movement disorders associated with dysregulation of brain iron. We also propose a new classification of NBIAs.
Health disparities and underserved populations: a potential solution, medical school partnerships with free clinics to improve curriculum

Health-care educators share the social responsibility to teach medical students about social determinants of health and health-care disparities and subsequently to encourage medical students to pursue residencies in primary care and medical practice in underserved communities. Free clinics provide care to underserved communities, yet collaborative partnerships with such organizations remain largely untapped by medical schools. Free clinics and medical schools in 10 US states demonstrate that such partnerships are geographically feasible and have the potential to mutually benefit both organizational types. As supported by prior research, students exposed to underserved populations may be more likely to pursue primary care fields and practice in underserved communities, improving health-care infrastructure.
Tympanometric screening in elementary school children.

The revised ASHA (American Speech Language Hearing Association, 1990) hearing screening guidelines were developed to decrease over-referrals for middle ear disorders through amended tympanometric measurements. These guidelines also recommended a large-scale normative study be done with tympanometric measures to further reduce the over-referral rate. Seven hundred and fifty ears from 392 kindergarten through third-grade children were tested. Normative values of Peak Ytmand tympanometric width were calculated by grade. For increasing grade level, there was an orderly increase in the mean Peak Ytmand a decrease in the mean tympanometric width. Sensitivity and specificity were calculated at 65 and 80% respectively, with a prevalence of 11%. Suggestions for improving sensitivity and specificity are discussed.
Pyrenebutyrate Leads to Cellular Binding, Not Intracellular Delivery, of Polyarginine-Quantum Dots

The intracellular, cytosolic, delivery of quantum dots is an important goal for cellular imaging. Recently, a hydrophobic anion, pyrenebutyrate had been proposed to serve as a delivery agent for cationic quantum dots as characterized by confocal microscopy. Using an extracellular quantum dot quencher, QSY-21, as an alternative to confocal microscopy, we demonstrate that quantum dots remain on the cell surface and do not cross the plasma membrane following pyrenebutyrate treatment, a result that is confirmed with transmission electron microscopy. Pyrenebutyrate leads to increased cellular binding of quantum dots rather than intracellular delivery. These results characterize the use of QSY-21 as a quantum dot quencher and highlight the importance of the use of complementary techniques when using confocal microscopy.
Ellipsometry Using a Retardation Plate as Compensator

The equations of ellipsometry are derived relating the specimen properties, ρ=tanψeiΔ, to the instrument settings P, A, and Q. The treatment differs from previous works in that both of the important parameters of the retardation plate are considered, namely, the retardation δ and the transmission ratio T, of the slow to the fast axis. Equations are developed which determine δ and T from the instrument readings. Conventional averaging procedures to obtain ψ from readings of A are shown to be valid; however, it is demonstrated that the usual procedures for obtaining Δ from readings of P are invalid and a correction is derived. Furthermore, an unsuspected source of error, namely, orientation of the retardation plate oblique to the light beam, is shown to produce large errors in some measurements.
Reducing power consumption and enhancing performance by direct slave-to-slave and group communication in Bluetooth WPANs

Bluetooth is a promising wireless technology aiming at supporting electronic devices to be instantly interconnected into short-range ad hoc networks. The Bluetooth medium access control protocol is based on the Master/Slave concept wherein any communication between slave devices has to go through the Master. While this model provides for simplicity, it incurs longer delay between any two slaves devices due to far from optimal packet forwarding, the use of double the bandwidth, and also wastes additional energy at the Master. Moreover, if more than two devices want to communicate as a group, this can only be achieved by either multiple unicast transmissions or a piconet-wide broadcast, clearly resulting in inefficiency. In this paper, we propose a novel Dynamic Slot Assignment (DSA) scheme whereby the Master device dynamically assigns slots to Slaves so as to allow them to communicate directly with each other without any Master intervention. This proposed communication architecture also provides for Quality of Service (QoS) requests, admission control, and multi-device conversation by which a multicast-like communication is implemented within a piconet. Through extensive simulation, we observe that DSA drastically enhances Bluetooth performance in terms of delay and throughput, while significantly reducing power consumption at the master and also of the overall piconet.
Effect of varying pesticide exposure duration and concentration on the toxicity of carbaryl to two field-collected stream invertebrates, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp. (Ephemeroptera: Heptageniidae)

The effect of exposure duration on the toxicity of a forest insecticide (carbaryl) was assessed under environmentally realistic exposure regimes against two stream invertebrates indigenous to the United States Pacific Northwest, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp. (Ephemeroptera: Heptageniidae). Laboratory bioassays were conducted to evaluate the relationship between pulsed exposures of 15, 30, and 60 min and toxicity for a range of chemical concentrations (10.2-1,730 microg/L). For Cinygma sp., the 50% lethal concentration (LC50) values were calculated as 848 microg/L (15 min), 220 microg/L (30 min), and 165 microg/L (60 min). The C. californica consistently had lower mortality at a given concentration compared with Cinygma sp. Fifteen- and 30-min exposures did not elicit 50% mortality with C. californica, and it had a 60-min LC50 of 1,139 microg/L. Time to 50% mortality over 96 h after a 15-, 30-, or 60-min exposure, with the rest of the test period in freshwater (PLT50), was a function of exposure duration and concentration. Analysis of symptomology throughout the test period for C. californica gave evidence of recovery from the knockdown and moribund states, but this was not the case for Cinygma sp. The pulse duration resulting in 50% mortality was calculated as 43 min for Cinygma sp. exposed at 204 microg/L and 16 min at 408 microg/L. A three-dimensional probit plane model [Y = -10.86 + 4.83(ln C) + 3.0(ln T)], where Y is probit mortality, C is concentration in microg/L and T is time in hours, was used to explain the interaction between concentration (microg/L) and duration of exposure (hours) for Cinygma sp.
Sputum club cell protein concentration is associated with pulmonary exacerbation in cystic fibrosis

Abstract Background Cystic fibrosis (CF) patients exhibit a progressive decline in lung function accelerated by intermittent pulmonary exacerbations. There are urgent needs for clinically relevant biomarkers to aid in the diagnosis and management of a CF pulmonary exacerbation, in addition to providing insight into its pathophysiology. Club cell secretory protein (CCSP) is produced by bronchial epithelial cells, known to have anti-inflammatory properties and may play a role in CF pulmonary exacerbations. Our objective was to measure sputum CCSP concentration during hospitalizations for CF pulmonary exacerbation and during quarterly outpatient clinic visits for 2years. We explored the correlations between CCSP concentration, lung function and markers of inflammation and infection. Methods In this prospective, longitudinal cohort study, expectorated sputum, blood and lung function data were collected from 45 CF patients during 68 hospitalizations for pulmonary exacerbation and 193 clinic visits. Sputum CCSP concentration was measured and sputum and blood were assayed with a panel of inflammatory cytokines. We used a repeated measures model to compare log transformed sputum CCSP concentrations across multiple time points and to correlate those concentrations with related clinical variables. Results Our population had a mean age of 29 (16–58 years), and a median FEV 1 %predicted of 60% (18–105%). Sputum CCSP concentration was significantly lower in the initial, interim and final exacerbation samples ( p =0.0021, p =0.0005 and p =0.0274, respectively) compared to outpatient visits. Sputum CCSP concentration was negatively associated with sputum neutrophil elastase concentration ( p =0.0373). Patients with Pseudomonas aeruginosa mucoid had a significantly lower sputum CCSP concentration ( p =0.0129). Conclusion Sputum CCSP concentration is associated with CF pulmonary exacerbation.
Managing memory impairment in patients with Alzheimer’s disease

SUMMARY Memory impairment in patients with Alzheimer’s disease (AD) may be treated with cholinesterase inhibitors. Attention, alertness, initiative and memory (indirectly) may be treated with memantine. In addition to pharmacologic treatments, nonpharmacologic treatments, including external systems and devices, participation in social activities and exercise, as well as the use of habits, pictures and strategies, improve memory. We believe that although memory loss cannot be halted, both pharmacologic and nonpharmacologic treatments may help to improve AD patients’ memory and allow them to continue independent activities. Patients with mild cognitive impairment due to AD may be treated with nonpharmacologic therapies and with off-label cholinesterase inhibitors.
Verbal Intercourse and Sexual Communication: Impediments to STD Prevention

The lack of a culturally sanctioned language with which to discuss sexual health issues with potential partners is a major obstacle to sexually transmitted disease (STD) control. Among couples just beginning a relationship discussions of sexual history and health can undermine normal efforts to present oneself to another in a favorable way. The issue of sexual discourse was investigated in interviews with 124 male and female adults from San Francisco California infected with genital herpes who volunteered to speak about their experiences with this STD. 35 women (51%) and 26 men (46%) reported they had never discussed STDs with partners or potential partners; only 6 women (8%) and 8 men (14%) always discussed them. Reluctance to engage in such discussions was related to fear of social rejection problems with emotional intimacy denial of risk shame and embarrassment and concerns about offending the partner. Discussions of AIDS and condom use tend to substitute for discourse about past relationships and STDs. Many with herpes use joking to mask the anxiety associated with revealing they have an STD. These findings confirm the delicate nature of the initiation of new sexual relationships. Verbal intercourse is seen as even more personally dangerous and socially risky than physical intercourse itself. Discussions of the reality of STDs threaten to unmask carefully constructed mutual representations. Although STD prevention programs often emphasize safe sex negotiation they neglect the emotional and social aspects of sexual relationships. Prevention programs need to develop a cultural language to break down taboos related to discussions of STDs.
A Bloch band based level set method for computing the semiclassical limit of Schrödinger equations

A novel Bloch band based level set method is proposed for computing the semiclassical limit of Schrodinger equations in periodic media. For the underlying equation, subject to a highly oscillatory initial data, a hybrid of the WKB approximation and homogenization leads to the Bloch eigenvalue problem and an associated Hamilton-Jacobi system for the phase in each Bloch band, with the Bloch eigenvalue be part of the Hamiltonian. We formulate a level set description to capture multi-valued solutions to the band WKB system, and then evaluate total homogenized density over a sample set of bands. A superposition of band densities is established over all bands and solution branches when away from caustic points. The numerical approach splits the solution process into several parts: (i) initialize the level set function from the band decomposition of the initial data; (ii) solve the Bloch eigenvalue problem to compute Bloch waves; (iii) evolve the band level set equation to compute multi-valued velocity and density on each Bloch band; (iv) evaluate the total position density over a sample set of bands using Bloch waves and band densities obtained in steps (ii) and (iii), respectively. Numerical examples with different number of bands are shown to demonstrate the capacity of the method.
Longitudinal variability in airway responsiveness in a population-based sample of children and young adults. Intrinsic and extrinsic contributing factors.

The degree and long-term variability of airway responsiveness to eucapneic hyperventilation with cold air was assessed in 287 children and young adults (< 23 yr of age) (735 challenge tests) enrolled in a longitudinal study of pulmonary function, 179 of whom underwent two to five cold-air challenge tests between 1982 and 1986. Survey-to-survey variability in airway responsiveness was assessed with computation of adjusted within-subject correlation coefficients for continuous measures of response (percent decrease in FEV1 after challenge) and with adjusted odds ratios for dichotomous outcomes (“positive” if percent decrease FEV1 ⩾ 0.13). The relationships between variability in responsiveness and the following variables were examined: age, baseline level of pulmonary function, presence of respiratory symptoms and illnesses, smoking exposures, season, level of ventilation achieved during testing, and temperature of the expired air. Airway hyperresponsiveness was demonstrated consistently over all surveys in...
PCR with Random Primers to Obtain Sequence from Yeast Artificial Chromosome Insert Ends or Plasmids

A technique that can be used to isolate vector/ insert j unctions from clones in vec­ tors, such as yeast artificial chromosomes and PIs, and to sequence plasmid inserts more rapidly has been developed. A vector primer is combined with single, randomly chosen oligonucleotides in PCRs, to create pools of products. ,With 12-24 random primers used in separate reactions, a given insert j unction can f requently be isolated. For plasmid inserts, multiple products are created that can be sequenced from their random-primed ends to provide internal coveragefor a clone. It is often possible to sequence a significant portion of an insert with one set of reactions. The speed and simplicity of the method in each case and its use of existing techniques and reagents make it appealing.
Evaluation of SiC devices in converter phase-leg at high temperature

SiC devices have obvious advantages comparing with conventional Si devices especially in high temperature range. This paper aims at developing a method of characterization SiC JFET conduction and switching performance in high temperature and calculating the loss of SiC JFET converters. Experimental results show that with SiC Schottky diode as anti-paralleling diode the reverse recovery in switching is improved and switching loss is less. Also, the turn-off time will decrease when the temperature rises, showing a better performance in high temperature. With the test results, the loss estimation method is developed. Then losses of two typical three-phase AC-DC-AC converters are calculated. Experimental results show that with Schottky diode as anti-paralleling diode, both conduction losses and switching losses can be reduced especially at high temperature.
Are Chronic Exposure To Violence and Chronic Violent Behavior Closely Related Developmental Processes During Adolescence

Five waves of longitudinal data from a sample of minority youth living in extreme poverty were used to examine the impact of chronic exposure to violence on chronic violent behavior. Given the rapid rate of developmental change during adolescence and the lack of multiyear studies of exposure to violence, semiparametric group-based modeling was used to identify trajectories of chronic exposure to violence (7% of youth), chronic violent victimization (9% of youth), chronic vicarious victimization (39% of youth), and chronic violent behavior (12% of youth). The multivariate findings revealed that (a) youth with chronic exposure to violence were 3,150% (or 31.5 times) more likely to engage in chronic violent behavior and (b) chronic vicarious victimization was a significant predictor of chronic violent behavior, after controlling for the effects of chronic violent victimization. The theoretical and policy implications of these findings as well as areas for future research are discussed.
Influence of amplitude and starting point on accommodative dynamics in humans.

PURPOSE. The effects of amplitude and the starting point of an accommodative response on the dynamics of far-to-near (accommodation) and near-to-far (disaccommodation) focus were studied. METHODS. Step responses were recorded with a dynamic optometer in nine 22- to 30-year-old subjects, under three conditions: (1) Fixed far: accommodative demands from 1 to 6 D were created by placing the far target at 6 m and the near target at various proximal distances. (2) Fixed near: accommodative demands from 1 to 5 D were created by placing the near target at 16.7 cm and the far target at various distal positions. (3) Fixed amplitude: far and near target positions were changed to create an accommodative demand of 1.5 D from starting positions of 1 to 4.5 D in 0.5-D steps. Each recorded response was fitted with an exponential function to calculate response amplitude, peak velocity, time constant, and starting point. RESULTS. The relationship between starting point and amplitude of accommodation and disaccommodation was effectively manipulated in the three conditions. For accommodation and disaccommodation, peak velocity increased linearly with response starting point, whereas the peak velocity versus response amplitude relationship differed according to the condition. Similar amplitude responses were associated with a higher peak velocity and a smaller time constant at proximal starting points than at distal starting points. Low-amplitude responses were influenced by both starting point and amplitude. CONCLUSIONS. The dynamics of accommodation and disaccommodation are strongly influenced by the starting point, but less so by amplitude.
The effect on quality of non-uniform fault coverage and fault probability

This paper addresses problems associated with the production and interpretation of traditional fault coverage numbers. The first part addresses the issue of non-uniform distribution of detected faults. It is shown that there is a large difference in final quality between covering the chip all over and leaving parts relatively untested, even if the coverage is the same in both cases. The second part deals with the use of weighted, rather than unweighted fault coverages and investigates the use of readily-available extracted capacitance information to produce a weighted fault coverage which is more useful for producing quality estimates, without having to perform a full defect analysis. Results show significant differences in weighted versus unweighted coverages, and also that these differences can be in either direction.
A hybrid system for modeling credit ratings for US airports

Developing credit ratings for public institutions requires procedures that enable analysts to consider a complex combination of quantitative and qualitative data in a manner that is verifiable, consistent, and reasonably transparent. The procedures must also provide rationale for the ratings and the ability to monitor those ratings on a regular basis. Rating agencies have tried to achieve these objectives by using expert analysts and rating committees. However, they find themselves increasingly challenged about the quality of their work, particularly the ongoing monitoring of all previously rated institutions. This work describes a successful hybrid system that combines fuzzy logic and expert systems to model the rating process for public airports.