cssi/SciSciGPT-SciSciNet huggingface dataset:
Maintaining the integrity of the enamel surface: the role of dental biofilm, saliva and preventive agents in enamel demineralization and remineralization.

ABSTRACT Background Dental caries is an infectious disease, and it affects 90 percent of late adolescents and young adults in the United States. It is a complex disease that occurs along the interface between the dental biofilm and the enamel surface. Results Many components in saliva are taken up by dental biofilm and protect the enamel surface. On the other hand, newly erupted teeth depend on the enamel pellicle for posteruption maturation of acid-susceptible substituted hydroxyapatite. When Streptococcus mutans colonizes dental biofilm, it depends on vertical transmission, horizontal transmission or both. These acidogenic, aciduric bacteria are considered to be the primary organisms responsible for enamel caries. The ability of the biofilm to sequester calcium, phosphate and fluoride from the saliva, as well as from sources outside the oral cavity allows enamel to undergo remineralization after demineralization. Optimal remineralization depends on the enamel surface's being exposed to low concentrations of calcium, phosphate and fluoride for prolonged periods. Outside sources of bioavailable calcium, phosphate and fluoride can alter dental biofilm's cariogenicity. Clinical Implications The use of sugar alcohols, povidone-iodine, delmopinol, triclosan and chlorhexidine may modulate the caries process. In addition, studies involving probiotics and molecular genetics have provided results showing that these methods can replace and displace cariogenic bacteria with noncariogenic bacteria, while maintaining normal oral homeostasis.
Constructive Struggle in Geometry Classrooms.

ABSTRACTThe purpose of these notes is to provide examples of large-scale geometry problems that have the potential to promote constructive struggling in high-school geometry classrooms. These probl...
Reply to Laing et al.: Accurate prediction of circadian time across platforms.

TimeSignature’s power is that it is highly accurate across transcriptomic platforms and experimental protocols. TimeSignature can be trained using data from a single platform/study and be applied to independent data without additional processing. Demonstrating this robustness and generalizability required applying TimeSignature to as diverse a set of studies as possible (i.e., refs. 1⇓⇓–4). Because not all studies had melatonin data, we chose to use draw time as a proxy for melatonin phase. Laing et al. (5) criticize this methodology; however, each of the studies (1⇓⇓–4) selected subjects for whom circadian phase was well aligned with local time. We have confirmed that dim-light melatonin onset (DLMO)25%, the time at which 25% of maximum blood melatonin is reached, is strongly correlated with local time in studies with available melatonin data (1⇓–3) (Fig. 1). As expected, training on local time thus accurately predicts melatonin phase (Fig. 2, oTS). Fig. 1. Comparison of circadian and clock … [↵][1]1To whom correspondence should be addressed. Email: rbraun{at}northwestern.edu. [1]: #xref-corresp-1-1
Two weeks of lower body resistance training enhances cycling tolerability to improve precision of maximal cardiopulmonary exercise testing in sedentary middle-aged females.

It is not uncommon for sedentary individuals to cite leg fatigue as the primary factor for test termination during a cardiopulmonary exercise test (CPET) on a cycle ergometer. The purpose of this s...
Exploring achievement goal theory, ACTFL's 5 Cs, and the L2 classroom: What goals do students set?

This study used achievement goal theory (AGT) in the Spanish second language (L2) classroom to determine what students' self‐selected goals are and how those goals relate to the ACTFL World‐Readiness Standards for Learning Languages (National Standards Collaborative Board, 2015). AGT is built on the concept of goal orientation, which is the natural tendency toward achievement‐seeking behavior. The four goal orientations are mastery approach, mastery avoidance, performance approach, and performance avoidance. The results of this mixed‐methods study show that the majority of students have mastery approach goals, but all four goal orientations were present across the sample population (N = 165). Results also indicate that 67.1% of students said that a top goal was communication and speaking, and 41.8% of students stated that grammar was a main goal. The findings that Communication (67.1%) and Cultures (2%) were the only two standards of the ACTFL 5 Cs (National Standards Collaborative Board, 2015) that were mentioned in students' goal statements and that Connections, Comparisons, and Communities were not mentioned at all indicate a disparity between what language learning entails and L2 learners' perceptions. Pedagogical implications are discussed.
The duration of strong mate-guarding by males of the libellulid dragonfly Paltothemis lineatipes : Proximate causation

Males of the territorial libellulid dragonfly Paltothemis lineatipeschange the intensity with which they guard their mates during an oviposition bout. Immediately after copulation is completed, males exhibit strong guarding, remaining very close to their partners as they begin ovipositing. In less than a minute, however, they begin to drift away to resume territorial patrolling or even to perch while their partners continue to oviposit. The duration of strong guarding is not related to how long the male has been on territory. Nor is it an activity of fixed duration set by the release of the female following copulation or by the initiation of oviposition by a panner. Instead, males can extend the period of strong guarding if oviposition is interrupted experimentally early in a bout. Under these conditions, males follow their mates closely until they have found a new location at which they oviposit steadily. Thus, males apparently must see their panner oviposit for some time before reducing the intensity of mate-guarding.
Generalizability and reproducibility of functional connectivity in autism

Autism is hypothesized to represent a disorder of brain connectivity, yet patterns of atypical functional connectivity show marked heterogeneity across individuals. We used a large multi-site dataset comprised of a heterogeneous population of individuals with autism and typically developing individuals to compare a number of resting-state functional connectivity features of autism. These features were also tested in a single site sample that utilized a high-temporal resolution, long-duration resting-state acquisition technique. No one method of analysis provided reproducible results across research sites, combined samples, and the high-resolution dataset. Distinct categories of functional connectivity features that differed in autism such as homotopic, default network, salience network, long-range connections, and corticostriatal connectivity, did not align with differences in clinical and behavioral traits in individuals with autism. One method, lag-based functional connectivity, was not correlated to other methods in describing patterns of resting-state functional connectivity and their relationship to autism traits. Overall, functional connectivity features predictive of autism demonstrated limited generalizability across sites, with consistent results only for large samples. Different types of functional connectivity features do not consistently predict different symptoms of autism. Rather, specific features that predict autism symptoms are distributed across feature types.
Generative Oversampling with a Contrastive Variational Autoencoder

Although oversampling methods are widely used to deal with class imbalance problems, most only utilize observed samples in the minority class and ignore the rich information available in the majority class. In this work, we use an oversampling method that leverages information in both the majority and minority classes to mitigate the class imbalance problem. Experimental results on two clinical datasets with highly imbalanced outcomes demonstrate that prediction models can be significantly improved using data obtained from this oversampling method when the number of minority class samples is very small.
Derivation of Airway Basal Stem Cells from Human Pluripotent Stem Cells

Summary The derivation of self-renewing tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would shorten the time needed to engineer mature cell types in vitro and would have broad reaching implications for the field of regenerative medicine. Here we report the directed differentiation of human iPSCs into putative airway basal cells (“iBCs”), a population resembling the epithelial stem cell of lung airways. Using a dual fluorescent reporter system (NKX2-1GFP;TP63tdTomato) we track and purify these cells over time, as they first emerge from iPSC-derived foregut endoderm as developmentally immature NKX2-1GFP+ lung progenitors which then augment a TP63 program during subsequent proximal airway epithelial patterning. These cells clonally proliferate, initially as NKX2-1GFP+/TP63tdTomato+ immature airway progenitors that lack expression of the adult basal cell surface marker NGFR. However, in response to primary basal cell medium, NKX2-1GFP+/ TP63tdTomato+ cells upregulate NGFR and display the molecular and functional phenotype of airway basal stem cells, including the capacity to clonally self-renew or undergo multilineage ciliated and secretory epithelial differentiation in air-liquid interface cultures. iBCs and their differentiated progeny recapitulate several fundamental physiologic features of normal primary airway epithelial cells and model perturbations that characterize acquired and genetic airway diseases. In an asthma model of mucus metaplasia, the inflammatory cytokine IL-13 induced an increase in MUC5AC+ cells similar to primary cells. CFTR-dependent chloride flux in airway epithelium generated from cystic fibrosis iBCs or their syngeneic CFTR-corrected controls exhibited a pattern consistent with the flux measured in primary diseased and normal human airway epithelium, respectively. Finally, multiciliated cells generated from an individual with primary ciliary dyskinesia recapitulated the ciliary beat and ultrastructural defects observed in the donor. Thus, we demonstrate the successful de novo generation of a tissue-resident stem cell-like population in vitro from iPSCs, an approach which should facilitate disease modeling and future regenerative therapies for a variety of diseases affecting the lung airways.
Emulsions Stabilized by Inorganic Nanoclays and Surfactants: Stability, Viscosity, and Implications for Applications.

Abstract Pickering emulsions, or emulsions with solid particles at the interface, have attracted significant interest in Enhanced Oil Recovery (EOR) processes, cosmetics, and drug delivery systems due to their ability to resist coalescence. Here, a synthetic clay nanoparticle, laponite®, is utilized to create oil-in-water (o/w) emulsions, and the addition of small-molecule surfactants induces a more stable emulsion. In this study, the stability of laponite® Pickering emulsions with and without the surfactants (dodecyltrimethylammonium bromide (DTAB), Pluronic F68 (F68), and sodium dodecyl sulfate (SDS) is investigated using dynamic light scattering (DLS), ζ-potential, optical microscopy, and rheology. With laponite® and no added surfactants, the DLS and ζ- potential results show formation of emulsion droplets with a diameter of 3 µm and a ζ-potential of −90 mV. With the addition of surfactants, both the droplet diameter and ζ-potential increase, suggesting adsorption of surfactants on the surface of laponite® particle. Optical microscopy suggests that the Pickering emulsion without surfactant undergoes flocculation, while the emulsion becomes stable to coalescence and creaming with addition of surfactants due to formation of a network structure. Regardless of the formation of network structure, the laponite®-F68 emulsion rheologically behaves as a Newtonian fluid, while the laponite®-SDS and laponite®-DTAB emulsions display shear thinning behavior. The difference in the rheological behavior can be attributed to the weak adsorption of F68 on laponite® and electrostatic interactions between laponite® and charged surfactants at oil-water interface.
Inbred Substrain Differences Influence Neuroimmune Response and Drinking Behavior

Background The inbred mouse strain C57BL/6 is widely used in both models of addiction and immunological disease. However, there are pronounced phenotypic differences in ethanol (EtOH) consumption and innate immune response between C57BL/6 substrains. The focus of this study was to examine the effects of substrain on innate immune response and neuroimmune-induced escalation of voluntary EtOH consumption. The main goal was to identify whether substrain differences in immune response can account for differences in EtOH behavior. Methods We compared acute innate immune response with a viral dsRNA mimic, polyinosinic:polycytidylic acid (poly(I:C)), in brain using qRT-PCR in both C57BL/6N and C57BL/6J mice. Next, we used a neuroimmune model of escalation using poly(I:C) to compare drinking behavior between substrains. Finally, we compared brain neuroimmune response with both EtOH and repeated poly(I:C) in both substrains as a way to account for differences in EtOH behavior. Results We found that C57BL/6 substrains have differing immune response and drinking behaviors. C57BL/6N mice have a shorter but more robust inflammatory response to acute poly(I:C). In contrast, C57BL/6J mice have a smaller but longer-lasting acute immune response to poly(I:C). In our neuroimmune-induced escalation model, C57BL/6J mice but not C57BL/6N mice escalate EtOH intake after poly(I:C). Finally, only C57BL/6J mice show enhanced proinflammatory transcript abundance after poly(I:C) and EtOH, suggesting that longer-lasting immune responses are critical to neuroimmune drinking phenotypes. Conclusions Altogether, this work has elucidated additional influences that substrain has on both innate immune response and drinking phenotypes. Our observations highlight the importance of considering and reporting the source and background used for production of transgenic and knockout mice. These data provide further evidence that genetic background must be carefully considered when investigating the role of neuroimmune signaling in EtOH abuse.
Modeling Stochastic Microscopic Traffic Behaviors: a Physics Regularized Gaussian Process Approach.

Modeling stochastic traffic behaviors at the microscopic level, such as car-following and lane-changing, is a crucial task to understand the interactions between individual vehicles in traffic streams. Leveraging a recently developed theory named physics regularized Gaussian process (PRGP), this study presents a stochastic microscopic traffic model that can capture the randomness and measure errors in the real world. Physical knowledge from classical car-following models is converted as physics regularizers, in the form of shadow Gaussian process (GP), of a multivariate PRGP for improving the modeling accuracy. More specifically, a Bayesian inference algorithm is developed to estimate the mean and kernel of GPs, and an enhanced latent force model is formulated to encode physical knowledge into stochastic processes. Also, based on the posterior regularization inference framework, an efficient stochastic optimization algorithm is developed to maximize the evidence lower-bound of the system likelihood. To evaluate the performance of the proposed models, this study conducts empirical studies on real-world vehicle trajectories from the NGSIM dataset. Since one unique feature of the proposed framework is the capability of capturing both car-following and lane-changing behaviors with one single model, numerical tests are carried out with two separated datasets, one contains lane-changing maneuvers and the other doesn't. The results show the proposed method outperforms the previous influential methods in estimation precision.
The effects of ovariectomy on the behavioral and physiological responses to constant light in C57BL6/J Mice

Circadian disruptions, including exposure to constant light, are known to produce behavioral and physiological issues. However, sex differences exist in how those problems manifest, as males tend t...
Epidural blood patch for post-dural puncture headaches in adult and paediatric patients with malignancies: a review.

Summary Many anaesthetists are hesitant to perform epidural blood patch in patients with cancer because of the potential risk of seeding the CNS with malignant cells. Recent evidence suggests that anaesthetists may view malignancy as a relative contraindication to epidural blood patch rather than an absolute contraindication. This review article summarises the clinical dilemma, reviews the existing literature, and proposes a treatment algorithm that includes the utilisation of for the management of post-dural puncture headache in the oncology population.
Cross-Cultural Communication in a Crisis: The Universality of Visual Narrative in the COVID-19 Pandemic (preprint)

When communication across language and cultural barriers is crucial, speakers across the globe get visual. In the 2020-21 COVID-19 crisis, government, inter-governmental, and private entities all looked to the universality of visual narrative to communicate urgent public health and safety messages. Speakers across the globe employed the symbolic modes of pictograms and ideograms and the longer form sequential narrative of cartoons and comics to warn and educate vast and diverse populations about the risks, dangers, and safety procedures concerning the novel coronavirus at the heart of the COVID-19 crisis. The COVID-19 crisis of 2020-21 has provided a natural experiment in communication of critical information regarding government-backed and government-mandated restrictions and recommendations to broad and diverse audiences through highly visual and pictorial media. Lawyers, judges, and law students can draw immediate lessons from the correlation of visual content and the nearly universal use of multimodal content employing both words and highly pictorial images. The goal of this Article is to apply the lens of visual legal rhetoric and narrativity, visual literacy analysis, and visual cultural studies to evaluate and critique representative examples of urgent public health and safety messages concerning the COVID-19 crisis. These communications used visual images as a means to overcome language and cultural barriers. Lessons can be drawn from these critical and urgent communications that can be applied to legal communications whose messages about the law and legal rights and obligations may not be as urgent in a time sense, but are no less urgent in terms of the need to communicate the message to the broadest possible audiences. Lawyers, judges, legislators, and regulators can read the examples in this study and be encouraged to make visuals a more integral part of legal works in transactional, litigation, legislative, regulatory, and legal informational contexts. Visuals can overcome barriers in communication that words alone cannot, and legal works can be made more universal in their communication, interpretation, performance, and enforcement if they are made more visual in content.
Estrogen-related Receptor Alpha (ERRα) is Required for PGC-1α-dependent Gene Expression in the Mouse Brain.

Abstract Deficiency in peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression or function is implicated in numerous neurological and psychiatric disorders. PGC-1α is required for the expression of genes involved in synchronous neurotransmitter release, axonal integrity, and metabolism, especially in parvalbumin-positive interneurons. As a transcriptional coactivator, PGC-1α requires transcription factors to specify cell-type-specific gene programs; while much is known about these factors in peripheral tissues, it is unclear if PGC-1α utilizes these same factors in neurons. Here, we identified putative transcription factors controlling PGC-1α-dependent gene expression in the brain using bioinformatics, and then validated the role of the top candidate in a knockout mouse model. We transcriptionally profiled cells overexpressing PGC-1α and searched for over-represented binding motifs in the promoters of upregulated genes. Binding sites of the estrogen-related receptor (ERR) family of transcription factors were enriched and blockade of ERRα attenuated PGC-1α-mediated induction of mitochondrial and synaptic genes in cell culture. Localization in the mouse brain revealed enrichment of ERRα expression in parvalbumin-expressing neurons with tight correlation of expression with PGC-1α across brain regions. In ERRα null mice, PGC-1α-dependent genes were reduced in multiple regions, including neocortex, hippocampus, and cerebellum, though not to the extent observed in PGC-1α null mice. Behavioral assessment revealed ambulatory hyperactivity in response to amphetamine and impairments in sensorimotor gating without the overt motor impairment characteristic of PGC-1α null mice. These data suggest that ERRα is required for normal levels of expression of PGC-1α-dependent genes in neurons, but that additional factors may be involved in their regulation. Significance statement The transcription factors with which PGC-1α interacts determine specificity of the transcriptional program it drives across cell populations, but those mediating its functions in parvalbumin-expressing neurons are unknown. Relative to other PGC-1α-interacting transcription factors, ERRα is enriched in parvalbumin-expressing neurons and shows robust spatial and temporal correlation with PGC-1α expression throughout the brain. ERRα is also necessary for PGC-1α-dependent transcription both in vitro and in vivo for metabolic and neuronal transcripts. These data suggest that ERRα is an important player in cell-specific PGC-1α-dependent transcription in the CNS and may play a role in regulating parvalbumin-expressing neuron maturation and function.
Stop! Are You Sure You Want To Throw Grandpa's Body Away?

=889472. 182. The "individual-as-information" needs fiduciaries, to protect both the "individual" and any property society allows. Experience shows these fiduciaries should be regulated, particularly if, as is likely, the "information" state is a long one. The example of the Cryonics Society of EMBEDDED VALUE OF HUMAN REMAINS? amply indicates, the potential for fiduciary malfeasance is considerable' 83 and societal regulation would be needed to protect beneficiaries from fiduciaries, particularly in the long run. History also illustrates that the interest of individuals and society are often at odds, and this too seems likely in the flash-frozen hypothetical. Sometimes the interests of individuals seem superior. Particular power blocks or ideologies may hijack the political process and attempt to perpetrate themselves against any fair aggregation of individual values. But even when fairly aggregated, society's majority values may be distorted by such influences as racism, homophobia and anti-Semitism, or descend into hysteria, such as the McCarthy era'84 . And undistorted, fairly aggregated majorities can seek to curtail legitimate individual rights, hence the U.S. Constitution's Bill of Rights.' 85 In some society-individual conflicts, the interests of society seem superior. Society needs wartime sacrifices, even those occluding individual survival, and to be able to quarantine infectious disease carriers. Society also has an interest in setting the outer limits of individual decisions. 186 Heroin addicts may be making rational individual choices, balancing individual short-term values against the cost of a dime bag, but society may keep "impaired" individuals from making harmful or wasteCalifornia is instructive. See Jane Fryer, Hundreds of Corpses Wait for Science To Bring Them Back to Life-The Human Deep Freeze, SUNDAY MAIL (Scot.) Aug. 13, 2006, at 36 ("Body freezing is not an area to cut comers. In 1981, the cryonics community was rocked when tanks holding corpses at the Cryonics Society of California sprang leaks, leading to bodies thawing and decomposing."). Nor is this the only concern. Laws can change or be changed. Information-asindividuals, and any wealth they are able to retain, would be subject to control of the living on a variety of different levels. See supra note 177. 183. One need only point to the Bishop trust. See generally SAMUEL P. KING & RANDALL W. RoTH, BROKEN TRUST: GREED, MISMANAGEMENT, & POLITICAL MANIPULATION AT AMERICA'S LARGEST CHARITABLE TRUST (2006) (describing the corrupt handing of Hawaii's largest land
A Review of “The Lucky Ones: One Family and the Extraordinary Invention of Chinese America”

Mae Ngai's book explores a difficult time in Chinese American history, the period of the Chinese Exclusion Act (1882–1943), when Chinese in the United States by law were forbidden from becoming nat...
Method for Correcting Laboratory Model Deep-Well Disposal System Data for Hydrostatic Pressure Effects

A pressure chamber for determining the effect of increased hydrostatic pressure on growth and metabolic activities of groundwater bacteria is described. The chamber was used to show that moderate increases in pressure (to about 100 atmospheres) result in increased growth of mixed cultures of industrial-injection-well bacteria and in the more complete degradation of formate and nitrate by these bacteria, as compared with identical cultures at atmospheric pressure.
Reciclaje humano en "Única mirando al mar" de Fernando Contreras

Este articulo ofrece al lector una vision un tanto diferente de la relacion que existe entre el ser humano y la basura. En la actualidad se ha generado una controversia entre el impacto que causa la basura en la sociedad. Los estudiosos en la materia han creado una nueva ciencia denominada basurologia, la cual se da a la tarea de estudiar las relaciones entre la basura y los seres humanos. En este estudio nos enfocamos en la novela Unica mirando el mar desde la perspectiva de la basurologia y como la vida de sus protagonistas esta determinada por su relacion con la basura de la cual dependen para subsistir en un mundo casi infrahumano. En este medio las personas aprenden un nuevo estilo de vida y de alguna manera ellos tambien encuentran la manera de reciclarse y darse una segunda oportunidad de vida.
Synthesis and frequency-dependent dielectric properties of epitaxial La1.875Sr0.125NiO4 thin films

Epitaxial thin films of La1.875Sr0.125NiO4 (lanthanum strontium nickelate, LSNO) have been synthesized by sputtering onto single crystal oxide substrates and their structural and dielectric properties are reported. High dielectric constants on the order of 107 have been measured up to 1 MHz in interdigitated capacitors with a frequency dependence that correlates with substrate imposed strain and texture. The observation of a high dielectric constant albeit with moderate loss tangent at high frequencies motivates further explorations of charge ordering phenomena in such complex oxides and serves to examine size effects on dielectric response by comparison with studies on bulk single crystal LSNO.
Pump and flow control subassembly of thermal control subsystem for photovoltaic power module

The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.
Caffeine and glucose homeostasis during rest and exercise in diabetes mellitus.

Caffeine is a substance that has been used in our society for generations, primarily for its effects on the central nervous system that causes wakefulness. Caffeine supplementation has become incre...
Neuroembryology and Neurogenesis

This chapter first introduces the embryonic development of the neural plate into the neural tube and then discusses the central nervous system (CNS). The proliferation, differentiation, and migration of the neuronal and neural-crest cells are discussed. Finally, current studies on perinatal neuronal apoptotic death and its prevention by survival factors are introduced.
Sensor Array Technology, Army

Today's commercial and military aircraft require significant manpower to provide operational readiness and flight safety. Aging aircraft fleets are much in need of new and innovative health-monitoring methods to prevent catastrophic failure and reduce life-cycle costs. The key needs for characterizing in situ structural integrity characteristics of corrosion and barely visible impact damage (BVID) to determine “damage susceptibility” must be addressed. This article presents a new concept for onboard real-time monitoring using conductive polymer sensor array technology. Keywords: Aircraft; Civilian; Sensing locations; Sensor development; Antennas
Comparison of Serum and Plasma Methylmalonic Acid Measurements in 13 Laboratories: An International Study

Background: Detection of cobalamin deficiency is increasingly important, and methylmalonic acid (MMA) appears to be a useful marker. Information on interlaboratory variation and on methodological differences for MMA in serum and plasma is limited. Methods: Using gas chromatography/mass spectrometry, 13 laboratories participated in a 2-day analysis of 8 serum and 11 EDTA-plasma specimens. Results were analyzed for imprecision, recovery, and differences among laboratories and methods. Results: The mean among-laboratory imprecision (CV) was 19% and 21% for serum and plasma samples, respectively, and 9.3% and 7.8% for serum and plasma samples with added MMA, respectively. The mean within-laboratory (among-run) CV was 13% for both serum and plasma samples and 5.2% and 4.9% for serum and plasma samples with added MMA. Within-method imprecision was the same or higher than among-method imprecision. The mean among-laboratory recovery of MMA was 105% and 95% in serum and plasma, respectively. Most laboratories showed a proportional bias relative to the consensus mean of up to 15%. Two laboratories reported results that on average were almost 30% higher than the consensus mean. Conclusions: No method differences were found, but significant among-laboratory imprecision was found in the present study. Improvements are needed to reduce the analytical imprecision of most laboratories, and attention must be focused on calibration issues. Differences among laboratories can be improved by introducing high-quality reference materials and by instituting external quality assessment programs.
The role of the service sector in Soviet GNP and productivity estimates

Abstract This paper examines the measurement of services within the real GNP accounts for the U.S. and the Soviet Union. Differences in measurement procedures create several biases in U.S.-Soviet comparisons. The paper recalculates levels and growth rates of GNP, and the shares of GNP produced by the Service sector for both the U.S. and the Soviet Union. The Soviet Union's relative performance improves when U.S. and Soviet services are measured using similar procedures. Also, recalculations of Soviet Total Factor Productivity growth show that it, too, has been underestimated.
Polarization and scattering characteristics in the atmospheres of earth, Venus, and Jupiter

Our understanding of atmospheric scattering phenomena has increased through the combined developments of new electro-optical instrumentation, theoretical solutions for complex model atmospheres, and large computers enabling computation of such solutions. Earth satellites permit external, planetwide observations of our atmosphere, while spacecraft permit detailed measurements of the scattering by other planetary atmospheres. Some recent results are: elucidation of the effects of ozone absorption and high-altitude aerosol scattering on twilight colors and polarization; identification of a cloudbow on Venus and consequent deduction of the cloud particle shape, size distribution, and refractive index; and, the interpretation of Rayleigh scattering on Jupiter in terms of cloud-top topography.
Evidence for the production and action of interleukin-10 in pituitary cells.

1. Interleukin-10 (IL-10) has a wide range of activities in the immune system such as modulation of interferon-gamma (IFN-γ) and antibody production. The neuropeptide hormone corticotropin (ACTH) has similar activities, suggesting that a bidirectional communication mechanism operates between the immune and the neuroendocrine system involving these two substances.
Text mutability and collection administration

I have been asked to make some brief, speculative comments about the possible long-range effects of the increasing availability of electronic information on collection building and administration. I will therefore limit my remarks to some thoughts on the place of collection development in a predominantly online information environment. I want to note at the outset that I agree fully with Peter Graham’s views expressed earlier at this conference on the role of technical services in what he calls “intellectu~ preservation,” and that my ideas will be quite consistent with his -although presented, of course, from the collection development side of the house [I]. Let us take as our point of departure that quality of online information which separates it most demonstrably from information available in more traditional forms: text mutability. Clearly the most revolutionary quality of the online format is that it empowers the user to enter easily and quickly into the text in order to add, delete, substitute, supplement, amalgamate, purge, manipulate-in short, to produce a personal text which uniquely suits the needs or inclinations of the individual user [2]. This capacity for unlimited adjustment is available regardless of whether the text is numerical or narrative (and indeed the narrative text is doubtless already coming increasingly to be perceived as a series of manipulable data elements). The broad implications of such text mutability have yet to be fully grasped either by bibliographic~ theorists or by library administrators. ff we understand the term fext in the broadest sense to indicate not only the physical signsthe print on the page or on the screenbut also the ideas to which such signs refer, then mutability is, of course, a quality of any text. The interpretation of the meaning of the text, the decryption of the signs, is after all a relatively subjective operation, depending as it does upon each individual’s continuously evolving textual experience. It is on the basis of that personal textual experience that each person assigns his or her meaning to the text; in this sense, therefore, the meaning of any text is constantly shifting. What makes communication possible at all under such circumstances (both communication between people, and “communication” with oneself-i.e., individual study and learning over time) is the relative stability of the material, graphic signs of which the physical text is composed. Communication depends upon a stable, objective text, to which different people can refer, and against which they can com-
Renal artery reconstruction for harvesting injuries in kidney transplantation with particular reference to the use of vascular allografts

At the University of Pittsburgh during the calendar year 1986, an arterial injury occurred during harvesting in 20 (7.5%) of the 270 grafts used to perform kidney transplantation (KTx). Four cases required reconstruction, using extension iliac arterial allografts from cadaveric donors of the same blood type; 6 patients, remodelling of the aortic patch in multiple arteries; 4 cases, repairs for injuries to the smaller segmental/polar arteries; 6 cases, a combination of the above techniques. These ex vivo arterial reconstructions are described and the use of donor arterial homografts is emphasized. No deaths have occurred at an average follow-up of 19 months. The postoperative acute tubular necrosis (ATN) rate was significantly higher (90%) compared with non-reconstructed kidneys during the same year (30%). The 1-year graft survival of kidneys undergoing arterial reconstruction (75%) was statistically no different than the overall kidney-transplant survival. Whenever extension iliac allografts were utilized, the cyclosporin-steroid immunosuppression required to control the kidney rejection contributed to the long-term patency rate of the graft. Since the number of organs available for grafting is limited, reconstruction of injured renal vessels has become justified, allowing valuable kidneys to be used that would otherwise be lost.
The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems

Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.
A reconsideration of the (in)sensitivity of tests of the intertemporal allocation of consumption to near rational alternatives

Abstract This paper uses micro data to show that the utility loss from near-rational behavior can be very significant. We calculate the utility loss from using a sub-optimal consumption allocation rule in a permanent income setting where utility is quadratic. In contrast to estimates derived from aggregate data (Cochrane, 1987), we find that small deviations from the optimal consumption allocation rule lead to large utility losses, more than $100/quarter (1983 dollars).
An electrooptical adder

A prototype for a binary adder, in which the carry propagation is handled by light signals is suggested, thus enabling a fast execution of addition operation even for large operands.
One-Stage Sternal Stenting With Homograft Bone After Cardiac Operation in Pediatric Patients

Low cardiac output after open heart operations in neonates and infants carries a high mortality. Delayed sternal closure may be life-saving but may prolong hospital stay and increase costs. To circumvent these issues, we shaped homograft bone and interposed it between the sternal edges to allow primary wound closure in 2 pediatric patients. Midterm results are satisfactory.
A structural analysis of the genotoxic and carcinogenic potentials of cyclosporin A.

The structural determinants identified by CASE, a knowledge-based structure--activity relational expert system, as contributing to toxicological effects have been distilled from the informational content of over 2000 molecules that have been adequately tested. This methodology has been applied to an analysis of the potential structural determinants of the mutagenicity, clastogenicity and carcinogenicity of cyclosporin A. The analysis predicts that cyclosporin A is devoid of mutagenicity, clastogenicity and DNA-modifying activity. There is however, a structural basis for its carcinogenicity in rodents, i.e. it appears to be a 'non-genotoxic' carcinogen. As a group, 'non-genotoxic' carcinogens are considered by some to pose a far lesser risk to humans than 'genotoxic' ones. The analysis is consistent with the interpretation that the carcinogenicity and immunosuppressive properties of cyclosporin A derive from different mechanisms and are, therefore, separable.
Proliferative Regeneration of Zebrafish Lateral Line Hair Cells after Different Ototoxic Insults

Sensory hair cells in the zebrafish lateral line regenerate rapidly and completely after damage. Previous studies have used a variety of ototoxins to kill lateral line hair cells to study different phenomena including mechanisms of hair cell death and regeneration. We sought to directly compare these ototoxins to determine if they differentially affected the rate and amount of hair cell replacement. In addition, previous studies have found evidence of proliferative hair cell regeneration in zebrafish, but both proliferation and non-mitotic direct transdifferentiation have been observed during hair cell regeneration in the sensory epithelia of birds and amphibians. We sought to test whether a similar combination of regenerative mechanisms exist in the fish. We analyzed the time course of regeneration after treatment with different ototoxic compounds and also labeled dividing hair cell progenitors. Certain treatments, including cisplatin and higher concentrations of dissolved copper, significantly delayed regeneration by one or more days. However, cisplatin did not block all regeneration as observed previously in the chick basilar papilla. The particular ototoxin did not appear to affect the mechanism of regeneration, as we observed evidence of recent proliferation in the majority of new hair cells in all cases. Inhibiting proliferation with flubendazole blocked the production of new hair cells and prevented the accumulation of additional precursors, indicating that proliferation has a dominant role during regeneration of lateral line hair cells.
Dark ionic flux and the effects of light in isolated rod outer segments.

We have determined the permeability properties of freshly isolated frog rod outer segments by observing their osmotic behavior in a simple continuous flow apparatus. Outer segments obtained by gently shaking a retina are sensitive but nonideal osmometers; a small restoring force prevents them from shrinking or swelling quite as much as expected for ideal behavior. We find that Na+, Cl-, No3-, glycerol, acetate, and ammonium rapidly enter the outer segment, but K+, SO4=, and melezitose appear impermeable. The Na flux is rectified; for concentration gradients in the physiological range, 2 x 109 Na+ ions/sec enter the outer segment, but we detect no efflux of Na+, under our conditions, when the gradient is reversed. Illumination of the outer segment produces a specific increase in the resistance to Na+ influx, but has no effect on the flux of other solutes. This light-dependent Na+ resistance increases linearly with the number of rhodopsin molecules bleached. We find that excitation of a single rhodopsin molecule produces a transient (∼1 sec) "photoresistance" which reduces the Na+ influx by about 1%, thus preventing the entry of about 107 Na+ ions. At considerably higher light levels, a stable afterimage resistance appears which reduces the Na influx by one-half when 106 rhodopsin molecules are bleached per rod. We have incorporated these findings into a model for the electrophysiological characteristics of the receptor.
The biosynthesis of estriol-3,16-disulfate by guinea pig liver homogenate.

Abstract Incubation of 3H-estriol in guinea pig liver homogenate fortified with uridine-5′-diphosphoglucuronic acid afforded a new conjugate in addition to the expected 3H-estriol-3-glucosiduronate. Employing methodology including chromatography on alumina and Celite, high voltage paper electrophoresis and reverse isotope dilution, its structure was established as estriol-3-16-disulfate. The chemical synthesis and some of the physical properties of the disulfate are described.
The effects of gossypol on nuclear protein in rat testes. I. Reduction in the content of basic proteins in the spermiogenic cells.

Abstract In rat testes, after 45 days of gossypol treatment, the number of round spermatids (RS) reduced from 9.8 × 10 6 to 6.2 × 10 6 per testis. The number of elongating spermatids (ES) reduced from 6.4 × 10 6 to 3.1 × 10 6 per testis. Total nuclear basic proteins (TNBP, i.e., somatic type of histones H 1 , H 2A, B , H 3 , and H 4 , plus testis-specific proteins TP 1,2,3 and sperm-specific S 1 proteins) were extracted from RS and ES. Gossypol has no detectable effect on the concentration of TNBP in RS. However, significant effect was found in ES, where the TNBP was reduced from 8.7 μg to 6.8 μg/10 6 cells. A two-stage polyacrylamide gel has been used to separate the TNBP and the individual proteins were quantified by a Beckman Model DU-7 computer-monitored spectrophotometer. In the RS cells, the content of the TNBP was not sensitive to gossypol. However, in the ES cells, the content of histones H 1 , H 2 A, and H 2 B were reduced by gossypol treatment (with an inhibition of 50%, 58%, and 31%, respectively). The inhibition on H 3 , TP 1 , T 3 and S 1 was insignificant by gossypol.
Self-assembling Peptides: From Bio-inspired Materials to Bone Regeneration:

In recent years, the development of new biomaterials with specifications for tissue and organ functional requirements-such as proper biological, structural, and biomechanical properties as well as designed control for biodegradation and therapeutic drug-release capacity-is the main aim of many academic and industrial programs. Hence, the concept of molecular self-assembly is the driving force for the development of new biomaterials that support the growth and functional differentiation of cells and tissues in a controlled manner. The discovery, properties, and development of self-assembling peptides to be used as three-dimensional (3D) scaffolds based on their similarity (in structure and mechanical features) to extracellular matrices are described. Self-assembling peptides can be used for in vitro applications for cell 3D culture as well as in vivo for tissue regeneration such as bone and optical nerve repair, as well as for drug delivery of mediators to improve therapy, as in the case of myocardial infarction. Finally, the use of self-assembling materials in combination with a bioengineering platform is proposed to assist functional bone regeneration in cases of larger bone defects, including exposed fractures due to trauma and spinal disorders dealing with high loadings, as well as replacement of big bone structures due to tumors.
Heat Flow in the Extraordinary Phases of Liquid He 3

In a heat-flow experiment at zero field we have found that the phase diagram of liquid $^{3}\mathrm{He}$ below the second-order transition at ${T}_{c}$ divides into two regions. In one the heat flow is linear and enhanced by an amount predicted by a two-fluid model; the other shows nonlinearity, history dependence, and critical-velocity effects. The two are separated by a line of thermal-resistance discontinuities which extrapolates to what may be a polycritical point at the line ${T}_{c}$ and possibly to the "$B$" feature at the melting line.