cssi/SciSciGPT-SciSciNet huggingface dataset:
How do Elementary Students Conceptualize Artificial Intelligence

Countries around the globe have acknowledged the pervasiveness of artificial intelligence (AI) in our lives and the importance of educating our students on how AI technologies work. For example, the Chinese education ministry has integrated AI into the mandatory high school curriculum, including a pilot textbook to teach students about the fundamental AI technologies like deep learning and recognition. However, there are fewer examples of AI education at the primary level, and these are typically focused on decision-making, machine learning, and programming. We have recently started to develop our own elementary AI curriculum. To develop the curriculum, we first needed to explore what students already knew about AI. Although there are a few small studies on how primary students conceptualize AI, we conducted a study to examine how 10 nine- and ten-year-old students conceptualized artificial intelligence by focusing on two main questions: (1) How do elementary students conceptualize artificial intelligence? (2) What are elementary students' experiences with artificial intelligence? Students? definitions of AI tended to focus on programming and robotics. Students described examples of AI that included robotic vacuums, Siri/Alexa, YouTube, and search engines. They also showcased some misconceptions around AI designs and implementations.
Laryngeal Chondrosarcoma

Laryngeal chondrosarcoma is a rare tumor requiring clinical, histologic, and radiographic correlation for definitive diagnosis. Although it typically presents with low-grade histology, even high-grade histology has a fairly indolent progression in this location, with a relatively low-likelihood for metastatic potential or recurrence. Because of this, conservative surgical excision with negative margins is recommended. We present a case of a laryngeal chondrosarcoma arising from the cricoid cartilage in a patient who presented with hoarseness, dysphagia, and odynophagia with subsequent head and neck computed tomography scan suggestive of the diagnosis. The patient was treated with hemicricoidectomy.
Serological and Molecular Detection of Anaplasma spp. in Blood From Healthy Horses: A Preliminary Study of Horses in East Texas

Abstract Anaplasmosis is a disease caused by the bacterium Anaplasma phagocytophilum, which is spread by infected ticks. In horses, A. phagocytophilum generally causes transient infection characterized by fever, lethargy, inappetence, ventral edema, petechiae, icterus, ataxia, recumbency, muscle stiffness, and, in severe cases, death. Following natural infection, horses retain antibodies for approximately 2 years, which can be detected through an immunofluorescence antibody assay. Current infections are determined through PCR assay of white blood cell DNA. For this study, whole blood was collected from apparently healthy horses located in East Texas (n = 70), west Texas (n = 3), New York (n = 49), and New Jersey (n = 11) for the determination of serum antibodies and PCR testing of bacterial DNA. Of the 133 horses, 24 tested positive for DNA presence of A. phagocytophilum, and 107 tested positive for serum antibodies. Of the 24 horses testing positive for A. phagocytophilum, 16 were positive for serum antibody presence and 8 were negative. Twenty of the msp2 positive horses were located in East Texas and 4 resided in New York. For serum antibodies, 100% of New York and New Jersey horses tested positive, while only 66% of Texas horses tested positive. This study provides evidence that a large number of horses are exposed to A. phagocytophilum and that this bacterium is present in East Texas. No Texas horse owners reported treatment for anaplasmosis, and the currently infected horses were not demonstrating signs of illness at the time of sample collection. Further research to understand the differences in disease severity amongst equine populations is warranted.
Immune Recognition of Stress Proteins in Infection and in Surveillance of Stressed Cells

Molecular biologists and immunologists have been investigating intensively the major antigens involved in the immune response to infection by mycobacteria, the causative agents of tuberculosis and leprosy. These two infectious diseases are a continuous threat to mankind. Recent WHO data indicates that as much as one third of the total population in the world is infected with Mycobacterium tuberculosis, and about 2–3 million people die from tuberculosis each year. About 10 million people in the world are infected with Mycobacterium leprae and stand at risk of incurring irreparable nerve damage (Bloom, 1989). The cloning and sequencing of genes coding for major mycobacterial protein antigens revealed that most of these proteins are members of stress protein (or heat shock protein) families (Young et al., 1988). This observation was unexpected because stress proteins occur in highly conserved forms in all organisms, from bacteria to man (Lindquist and Craig, 1988). The discovery raised questions about how immune cells could distinguish bacterial stress proteins and human stress proteins, and why the immune system would treat stress proteins as major targets when such recognition runs the risk of producing autoimmune disease (reviewed in Kaufmann, 1990; Young, 1990; Young and Elliott, 1989).
Controlling Grain Growth

A thermodynamic view is taken to explain how inclusions and lattice strains (developed when adjacent grains have slightly different lattice parameters) can be used to control grain growth in advanced ceramics. Experimental data are presented for the cases where A12O3 inclusions are used to inhibit normal grain growth in cubic ZrO2, ZrO2 inclusions inhibit abnormal grain growth of A12O3 and, compositional differences between adjacent grains, developed during slow partitioning, dramatically inhibit grain growth for compositions fabricated in the two-phase region of the ZrO2-Y2O3 system.
The andrology laboratory in an assisted reproductive technologies program : quality assurance and laboratory methodology

Assuring the highest possible quality of care to the patient is the first goal of the andrology laboratory. Quality control and quality assurance as they apply to the andrology laboratory are outlined, and special problems in quality control for sperm function assays are addressed. An example of the patient review process is presented. Quality of care also depends on the ability of the laboratory to perform appropriate tests of sperm function that can diagnose sperm defects, predict success or failure of in vitro fertilization, and lead to rational therapies for sperm dysfunctions. Methods for, and diagnostic value of, sperm swim-out, enhanced sperm penetration assays, acrosome reaction assessment, motility analysis of capacitating sperm, and sperm-zona binding assays are reviewed. No single test, other than in vitro fertilization itself, is capable of providing a complete diagnosis or a highly accurate prediction. A battery of sperm function tests, arranged in an algorithm, is presented as a theoretically better approach.
Virtual test tubes

By their structure and operation, biomolecules have resolved fundamental problems as a distributed computational system that we are just beginning to unveil. One advantageous approach to gain a good understanding of the processes and algorithms involved is simulation on conventional computers. Simulations allow better understanding of the capabilities of molecules because they can occur at the level of reliability, efficiency, and programmability that are standard in conventional computation and are desirable for experiments in vitro. Here, we describe in some detail the architecture of a general-purpose simulation environment in silico, EdnaCo, establish its soundness and reliability, and benchmark its performance. The system can be described as an emulation of the events in a real test tube. We describe the major pieces of its architecture, namely, a distributed memory (file) system, a kinetic engine, and input/output mechanisms. Finally, the ability of this environment in preserving major features of the wet counterpart in vitro is evaluated via an implementation on a cluster of PCs. The results of several simulations are summarized that establish the soundness, utility, applicability, and cost efficiency of the software to facilitate experimentation in vitro.
Optical packet switching

In this talk we will describe the motivation, background and state-of-the-art in optical packet switching architectures, the underlying technology and challenges. Recent optical packet switching demonstration at data rates from 2.5 Gbps to 160 Gbps will be described.
Bromine–1,4‐Dioxane

[15481-39-7] C4H8Br2O2 (MW 247.91) InChI = 1S/C4H8O2.Br2/c1-2-6-4-3-5-1;1-2/h1-4H2; InChIKey = DTLTUUJDCNTTSN-UHFFFAOYSA-N (reagent for bromination of phenols,2 aromatic amines,3 α-bromination of aldehydes4 and ketones5) Alternate Name: dioxane dibromide. Physical Data: mp 60 °C. Solubility: sol 1,4-dioxane, THF, and ether. Preparative Methods: a 1∶1 complex between 1,4-dioxane and bromine has been prepared and isolated on a 2 mol scale by the addition of bromine to 1,4-dioxane.6 The reagent has also been prepared in situ.3, 7 Handling, Storage, and Precautions: the complex is reported to be volatile (much material was lost on drying).6 It can be stored at 0 °C. This material should only be handled in a fume hood.
Jose van Dijck: Culture of Connectivity: A Critical History of Social Media. Oxford: Oxford University Press. 2013

Jose van Dijck: Culture of Connectivity: A Critical History of Social Media. Oxford: Oxford University Press. 2013
A Review of “Passing the Plate: Why American Christians Don't Give Away More Money”

Sociologists Christian Smith and Michael O. Emerson embark on their second joint venture to investigate another phenomenon involving Christianity in America. Previously, they explored the contentio...
The regulatory sulfhydryl group of Penicillium chrysogenum ATP sulfurylase: cooperative ligand binding after SH modification; chemical and thermodynamic properties

Abstract ATP sulfurylase from Penicillium chrysogenum is a homohexamer that contains three free sulfhydryl groups/subunit, only one of which (designated SH-1) can be modified by disulfide, maleimide, and halide reagents under nondenaturing conditions. Modification of SH-1 has only a small effect on kcat but causes the [S]0.5 values for MgATP and SO4(2-) (or MoO4(2-) to increase by an order of magnitude. Additionally, the velocity curves become sigmoidal with a Hill coefficient (nH) of about 2 (Renosto, F., Martin, R. L., and Segel, I. H. (1987) J. Biol. Chem. 262, 16279-16288). Direct equilibrium binding measurements confirmed that [32P]MgATP binds to the SH-modified enzyme in a positively cooperative fashion (nH = 2.0) if a sulfate subsite ligand (e.g. FSO3-) is also present. [35S]Adenosine 5'-phosphosulfate (APS) binding to the SH-modified enzyme displayed positive cooperativity (nH = 1.9) in the absence of a PPi subsite ligand. The results indicate that positive cooperativity requires occupancy of the adenylyl and sulfate (but not the pyrophosphate) subsites. [35S]APS binding to the native enzyme displayed negative cooperativity (or binding to at least two classes of sites). Isotope trapping profiles for the single turnover of [35S]APS: (a) confirmed the equilibrium binding curves, (b) indicated that all six sites/hexamer are catalytically active, and (c) showed that APS does not dissociate at a significant rate from E.APS.PPi. The MgPPi concentration dependence of [35S]APS trapping was indicative of MgPPi binding to two classes of sites on both the native and SH-modified enzyme. Inactivation of the native or SH-modified enzyme by phenylglyoxal in the presence of saturating APS was biphasic. The semilog plots suggested that only half of the sites were highly protected. The cumulative data suggest a model in which pairs of sites or subunits can exist in three different states designated HH (both sites have a high APS affinity, as in the native free enzyme), LL (both sites have a low APS affinity as in the SH-modified enzyme), and LH (as in the APS-occupied native or SH-modified enzyme). Thus, the HH----LH transition displays negative cooperativity for APS binding while the LL----LH transition displays positive cooperativity. The relative reactivities of like-paired SH-reactive reagents were in the order: N-phenylmaleimide greater than N-ethylmaleimide; dithionitropyridine greater than dithionitrobenzoate; thiolyte-MQ greater than thiolyte-MB. The log kmod versus pH curve indicates that the pKa of SH-1 is greater than 9.(ABSTRACT TRUNCATED AT 400 WORDS)
Identification of cathode materials for lithium batteries guided by first-principles calculations

Lithium batteries have the highest energy density of all rechargeable batteries and are favoured in applications where low weight or small volume are desired — for example, laptop computers, cellular telephones and electric vehicles1. One of the limitations of present commercial lithium batteries is the high cost of the LiCoO2 cathode material. Searches for a replacement material that, like LiCoO2, intercalates lithium ions reversibly have covered most of the known lithium/transition-metal oxides, but the number of possible mixtures of these2,3,4,5 is almost limitless, making an empirical search labourious and expensive. Here we show that first-principles calculations can instead direct the search for possible cathode materials. Through such calculations we identify a large class of new candidate materials in which non-transition metals are substituted for transition metals. The replacement with non-transition metals is driven by the realization that oxygen, rather than transition-metal ions, function as the electron acceptor upon insertion of Li. For one such material, Li(Co,Al)O2, we predict and verify experimentally that aluminium substitution raises the cell voltage while decreasing both the density of the material and its cost.
Coupling between apical tension and basal adhesion allow epithelia to collectively sense and respond to substrate topography over long distances

Epithelial sheets fold into complex topographies that contribute to their function in vivo. Cells can sense and respond to substrate topography in their immediate vicinity by modulating their interfacial mechanics, but the extent to which these mechanical properties contribute to their ability to sense substrate topography across length scales larger than a single cell has not been explored in detail. To study the relationship between the interfacial mechanics of single cells and their collective behavior as tissues, we grew cell-sheets on substrates engraved with surface features spanning macroscopic length-scales. We found that many epithelial cell-types sense and respond to substrate topography, even when it is locally nearly planar. Cells clear or detach from regions of local negative curvature, but not from regions with positive or no curvature. We investigated this phenomenon using a finite element model where substrate topography is coupled to epithelial response through a balance of tissue contractility and adhesive forces. The model correctly predicts the focal sites of cell-clearing and epithelial detachment. Furthermore, the model predicts that local tissue response to substrate curvature is a function of the surrounding topography of the substrate across long distances. Analysis of cell–cell and cell–substrate contact angles suggests a relationship between these single-cell interfacial properties, epithelial interfacial properties, and collective epithelial response to substrate topography. Finally, we show that contact angles change upon activation of oncogenes or inhibition of cell-contractility, and that these changes correlate with collective epithelial response. Our results demonstrate that in mechanically integrated epithelial sheets, cell contractility can be transmitted through multiple cells and focused by substrate topography to affect a behavioral response at distant sites.
4-(Lithiomethyl)-2, 6-Di-T-Butylpyridine: A Useful Precursor for the Synthesis of Bis(2, 6-Di-T-Butyl)Pyridyl Compounds

Abstract Reaction of 4-(lithiomethyl)-2, 6-di-t-butylpyridine (2) with one-half equiv of l2 produces 1, 2-bis(2, 6-di-t-butylpyridyl)-ethane (3) in 88% isolated yield. Treatment of 2 with 1, 2-bis-(chloromethyl)benzene affords the new compound 1, 2-bis[2-(2, 6-di-t-butylpyridyl)ethyl] benzene (4) in fair yield. Compound 4 can be utilized in vinyl trilate preparations where it is found that the bis(pyridinium)triflate salt is an oil!
Electroencephalographic registration of low concentrations of isoamyl acetate.

Abstract Previous research has demonstrated electroencephalogram (EEG) changes in response to low-odor concentrations, resulting in near-chance detection. Such findings have been taken as evidence for olfaction without awareness. We replicated and extended previous work by examining EEG responses to water–water control, 0.0001, 0.001, 0.01, and 1 ppm isoamyl acetate (IAA) in water paired with water only. Detection was above chance (>50%) for .001 and above, and alpha decreased only to those concentrations, suggesting that EEG changes corresponded to IAA awareness. However, when correct trial EEGs were compared to incorrect trial EEGs during .001 ppm, right posterior/central alpha decreased during incorrect trials and alpha decreased more globally (including frontal sites) during correct trials. These data may not reflect awareness or unawareness per se. Instead, results are discussed regarding activation of perceptual systems in the posterior region during incorrect trials and the activation of frontal action systems during a subset of correct trials.
A Soft X-Ray Photoemission Study of the Chemisorption and Reaction of Diethylsilane on SI(100)

Soft x-ray synchrotron radiation was utilized as the excitation source in a high-resolution photoemission experiment on chemisorption and subsequent reaction of diethylsilane on the Si(100) surface. We have found that diethylsilane chemisorbs dissociatively to form Si-CH{sub 2}CH{sub 3} surface species on Si(100) following a room temperature exposure. These species are identified by two very sharp peaks observed in the valence band spectra positioned at 17.9 and 14.3 eV binding energy. In addition, C 1s core level spectra, measured following exposures of Si(100) substrates as a function of surface temperature, show that carbon, in some form, exists on the Si surface following exposures at every temperature from room temperature to about 600C. While only {minus}CH{sub 2}CH{sub 3}, ethyl groups are observed on the surface at room temperature, these species appear to partially dehydrogenate at 300C, producing a mixture of {minus}CH{sub 2}CH{sub 3} groups and other intermediate carbonaceous species. At a growth temperature of about 400C the intermixing of elemental carbon with Si begins. At higher temperatures, we observe the continued degradation of diethylsilane to produce a Si + C alloy on the surface at 600C. Results indicate that diethylsilane has potential as a molecular precursor for SiC formation by chemical vapormore » deposition techniques.« less
Piezomagnetic Response with Depth, Related to Tectonomagnetism as an Earthquake Precursor

Piezomagnetic field variations can result from tectonic stress changes in the focal zone of an impending earthquake. Interpretation of such observed tectonomagnetic effects requires modeling of the stress response of magnetic properties of the lithosphere. Calculations have been made to estimate the here piezomagnetic effect as a function of depth, by considering the effect of stress on the magnetization of magnetite (Fe3O4) with increasing temperature and hydrostatic pressure. The responsiveness of magnetization to seismotectonic stress is gauged by an appropriate balancing of magnetocrystalline and magnetoelastic anisotropy energies. The calculations indicate that magnetite becomes progressively more responsive to stress at depth increases. The rate of change depends on the local geothermal gradient. The upper 15 km of the lithosphere is likely to be the most important in yielding observable piezomagnetic field effects. Such shallow-focus earthquakes are expected to be best for monitoring tectonomagnetic anomalies for earthquake prediction.
Lidocaine removal during resin hemoperfusion for phenobarbital intoxication.

: A deeply comatose patient with severe phenobarbital intoxication was hemoperfused with an Amerlite XAD-4 column. She was receiving lidocaine for ventricular ectopy. The rate of lidocaine infusion had to be increased to control ventricular arrhythmias during hemoperfusion. Plasma clearance for lidocaine by the column was 122 ml/min at initiation and 75 ml/min at 2 h. These findings suggest that an increment in lidocaine infusion may be needed during resin hemoperfusion in patients receiving this drug because of its removal by the column.
Prevention of thrombosis with warfarin, aspirin, and mechanical methods.

Venous thromboembolism (VTE) is a serious disorder and a major cause of morbidity and mortality among acutely ill medical patients. However, despite the growing number of patients with acute medical illnesses who have an associated risk of VTE, the widespread use of WE prophylaxis does not yet occur for both surgical and nonsurgical patients. Although individuals at greatest risk for WE include patients undergoing major orthopedic surgery and those with medical conditions that require prolonged immobilization, all patients who have acute medical illnesses should be considered for WE prophylaxis. Several strategies, including various mechanical and pharmacologic approaches, are currently used for WE prophylaxis. Increased awareness about the full range of options for WE prophylaxis can help health care providers select the appropriate course of action to help reduce the incidence of WE among patients with acute medical illnesses.
Lipid metabolism of insects: chain shortening of a long-chain dietary fatty acid.

Abstract 1. 1. The boll weevil, Anthonomus grandis Boheman, was reared on diets containing 9,10-[ 3 H]stearic acid or 3-[ 14 C]stearic acid. The total fatty acids of larvae, pupae and adults were analysed for distribution of radioactivity to other fatty acids. 2. 2. About 7% of the 3 H label and 12% of the 14 C label were found in the 16-carbon saturated and monoenoic fatty acids. 3. 3. Decarboxylation of the 16-carbon saturated fatty acid of pupae from the 3-[ 14 C]stearic acid diet showed that all the label was in the 1 position, thereby indicating that the dietary stearic acid was directly chain shortened to 1-[ 14 C]palmitic acid.
RECOMBINANT HUMAN GRANULOCYTE COLONY STIMULATING FACTOR (rhGCSF) ALTERS SURFACE EXPRESSION OF Fcγ& COMPLEMENT RECEPTORS IN NEUTROPENIC NEONATES IN VIVO. ▴ 1318

Fcγ and Complement receptors are present on neutrophils and facilitate elimination of antibody-coated neonatal pathogens including bacteria and fungi through opsonization, enhanced chemotaxis and increased cytotoxic killing. Low levels of these receptors are thought to contribute to an increased susceptibility of sick VLBW neonates to infections with these organisms. To determine whether rhGCSF could increase the density of Fcγ and Complement receptors per cell as well as the absolute number and percentage of neutrophils expressing this phenotype, we treated persistently neutropenic (>24h) neonates with rhGCSF (10 ug/kg × 3d, IV). The average weight of the study subjects was 1380±333g at 29±1 wks gestation (x±SEM); all but one were 3d) of pre-eclamptic women (PET, n=7) responded by increasing their ANC by 8- & 17-fold at 3 & 7d. FcγI, FcγII, CR1 and CR3 increased at 3d whereas FcγRIII increased only by 7d; similar to results published from non-neutropenic healthy adult volunteers. In contrast, septic neonates (n=6) showed a decrease in receptor density per cell despite a ≈30-fold rise in neutrophil cell number (see our related abstract SPR '96). This suggests that the high mortality associated with neutropenia during neonatal septicemia may be contributed to by mechanisms that prevent expression of these functional molecules or by factors that result in their down-regulation or consumption. By analogy, the risk of sepsis in PET-associated neutropenia would appear to be dependent on the absolute neutrophil count (ANC) and not primarily on rhGCSF-responsive receptor levels. We speculate that a rise in the ANC may not necessarily predict effectiveness of neutrophil function in septic neonates due to the expected impairment of opsonization in receptor-deficient cells.(Supported in part by a basic research grant from the Amgen Corporation).
Acceptability and Preliminary Efficacy of a Tailored Online HIV/STI Testing Intervention for Young Men who have Sex with Men: The Get Connected! Program

Southeast Michigan accounts for over 70 % of all HIV/STI cases in the state, with young men who have sex with men (YMSM) between the ages of 13 and 24 encumbering the largest burden in HIV/STI incidence. Using community-based participatory research principles, we developed and pilot tested a web-based, randomized control trial seeking to promote HIV/STI testing (“Get Connected!”) among YMSM (N = 130; ages 15–24). Randomized participants completed a baseline assessment and shown a test-locator condition (control) or a tailored, personalized site (treatment). At 30-day follow-up, we found high acceptability among YMSM in both conditions, yet higher credibility of intervention content among YMSM in the treatment group (d = .55). Furthermore, 30 participants reported testing by following, with the majority of these participants (73.3 %; n = 22) completing the treatment condition, a clinically meaningful effect (d = .34) suggesting preliminary efficacy for the intervention. These results demonstrate the potential of the intervention, and suggest that a larger efficacy trial may be warranted.
Error detection performance in a proportion estimation task

This study established some baseline data in an error detection task involving proportion estimation. Stimuli consisted of a standard random arrangement of 100 “+” signs with a variable number of + signs circled. With each stimulus presentation, Ss attempted to detect an error or difference between the actual number of + signs circled and a numerical estimate provided with the presentation. The detection data were utilized to calculate differential thresholds for error detection. Performance was superior with proportions less than 50%. Ss detected negative errors, i.e., when the numerical estimate provided was less than the actual number of + signs circled, better than positive errors.
Complete Genome and Clinicopathological Characterization of a Virulent Newcastle Disease Virus Isolate from South America

Newcastle disease (ND) is one of the most important diseases of poultry, negatively affecting poultry production worldwide. The disease is caused by Newcastle disease virus (NDV) or avian paramyxovirus type 1 (APMV-1), a negative-sense single-stranded RNA virus of the genus Avulavirus, family Paramyxoviridae. Although all NDV isolates characterized to date belong to a single serotype of APMV-1, significant genetic diversity has been described between different NDV isolates. Here we present the complete genome sequence and the clinicopathological characterization of a virulent Newcastle disease virus isolate (NDV-Peru/08) obtained from poultry during an outbreak of ND in Peru in 2008. Phylogenetic reconstruction and analysis of the evolutionary distances between NDV-Peru/08 and other isolates representing established NDV genotypes revealed the existence of large genomic and amino differences that clearly distinguish this isolate from viruses of typical NDV genotypes. Although NDV-Peru/08 is a genetically distinct virus, pathogenesis studies conducted with chickens revealed that NDV-Peru/08 infection results in clinical signs characteristic of velogenic viscerotropic NDV strains. Additionally, vaccination studies have shown that an inactivated NDV-LaSota/46 vaccine conferred full protection from NDV-Peru/08-induced clinical disease and mortality. This represents the first complete characterization of a virulent NDV isolate from South America.
Fat metabolism in experimental obesities. VIII. Blood total lipids and ketones in four kinds of obese mice.

Chez la Souris, l'obesite «de regulation» (ici: l'obesite hypothalamique due a l'aurothioglucose) comme les obesites «de metabolisme» (exemples: syndrome recessif d'obesite-hyperglycemie, syndrome dominant d'obesite «jaune», obesite due aux tumeurs secretant l'ACTH) sont accompagnees d'hyperlipemie, accentuee par le jeune. Par contre si, comme les souris normales, les souris obeses hypothalamiques reagissent au jeune par une augmentation de la cetonemie, les souris hereditairement obeses reagissent au jeune par une diminution de la cetonemie, une reaction qui peut s'ajouter a celles qui differencient les obesites «de metabolisme» des obesites «de regulation».
Nuclear rocket propulsion principle

Abstract A high specific impulse, high thrust nuclear rocket propulsion principle is presented for discussion. The fission fuel retention problem is solved dynamically by a pulsed operation through a fast growing chain reaction.
Genentech: The Beginnings of Biotech

Over the past twenty years, Sally Smith Hughes has done a great service to historians by conducting in-depth oral history interviews with prominent scientists, venture capitalists, corporate leader...
Refractory periodontitis: critical questions in clinical management

Abstract Refractory periodontitis appears to be a patient phenomenon with a clinical pattern that may be the result of different influences including genetic factors and exogenous factors that alter the host response to the bacterial challenge. Different patients may have different mechanisms involved in their disease and therefore may show different response patterns following therapy. Although localized non-responsive sites in otherwise responsive patients should not be considered refractory periodontitis such sites do present substantial therapeutic problems. Initial evidence suggests that local delivery tetracycline provides significant advantages in the management of such sites. Although refractory periodontitis cases appear to be primarily the result of host alterations, the most predictable approach to therapy at present involves systemic antibiotics in conjunction with local therapy. The goal of antibiotic therapy should be to eliminate from detection the target bacteria that were present prior to therapy. Good plaque control, regular professional maintenance therapy, regular microbial monitoring, and control of risk factors are important aspects of the long term maintenance of these cases.
Fire injuries, disasters, and costs from cigarettes and cigarette lights: a global overview

Abstract Background. Fires cause 1% of the global burden of disease. Fire (includes explosion) disasters have immense health, social, and environmental costs. We will provide initial estimates of overall U.S. and global fire tolls from smoking. Methods. We tabulated and summarized smoking-related fire and disaster tolls from published documents. We compared those tolls to U.S. fire, burn, and fire death rates per billion cigarettes extrapolated globally. Smoking-attributable percentages of adult and child access to cigarette lighter and match ignitions (lights), and resultant fires, burns, and deaths ignited by young children, were estimated from likely smoking-attributable lights usage. Cigarette plus cigarette lights fire tolls were multiplied times published and estimated fire costs. Results. Smoking is the leading cause of residential or total fire death in all eight countries with available statistics. Smoking is a leading cause of fires in many more countries. Cigarettes cause numerous fire disasters. Cigarette lights cause an estimated 100,000 U.S. and one million global, child-playing fires per year. Cigarette lights fire injuries likely rival U.S., and possibly global, cigarette fire injury numbers. Smoking causes an estimated 30% of U.S. and 10% of global fire death burdens. Smoking's estimated U.S. and global fire costs were $6.95 (sensitivity range $5.34–22.8) and $27.2 (sensitivity range $8.2–89.2) billion, respectively, in 1998 U.S. dollars. Conclusions. Smoking likely causes large global fire tolls. U.S. fire tolls have fallen when smoking decreased. Further reducing smoking can substantially reduce fire and disaster tolls.
Thermal oxidation of single crystal aluminum nitride — A high resolution transmission electron microscopy study

Abstract The impact of the oxidation time on the structures of thermal oxides formed on AlN was determined by high resolution transmission electron microscopy (HRTEM). Oxidation of AlN single crystals was performed for 2 to 6 h at 1000 °C. Oxidation for 2 h produced mostly amorphous oxide layers whereas oxidation for both 4 and 6 h produced partially crystalline oxide layers. The oxide layer thickness varied from 205 to 600 nm for oxidation times of 2 and 6 h respectively. The crystalline oxide was mostly single phase α-Al 2 O 3 except at the surface where it was a mixture of γ-Al 2 O 3 and α-Al 2 O 3 . Based on the different structures produced for different oxidation times, we speculate that the oxide formed changes with thickness: first an amorphous oxide, then γ-Al 2 O 3 , and finally α-Al 2 O 3 as the oxide thickness increases. The AlN crystal was nearly defect- and oxygen-free for oxidation at 1000 °C. This could be due to the rapid diffusion of the nitrogen and aluminum interstitials at a high temperature leading to a point-defect equilibrium throughout the nitride. A faceted interface between Al 2 O 3 and AlN could be attributed to the surface diffusion to minimize energy.
Intrinsic Structure-Reactivity Relationships in Gas-Phase SN2 Reactions: Identity Exchange of Substituted Benzyl Chlorides with Chloride Ion

The identity transacylation reactions of chloride with several substituted benzoyl chlorides, Cl- + XC6H4COCl, have been investigated. For X = p-CH3, m-CH3, H, m-OCH3, m-F, and m-CF3, the complexat...
Scanning force microscopy and effective medium theory study of free‐standing polyaniline thin films

The technique of scanning force microscopy was used to study the nanometer-scale structure of NMP cast films of polyaniline. Noncontact mode images provide direct evidence that polyaniline prepared in this form is a granular conductor. The films were found to consist of micrograins whose size and density were determined by the pH of the acid solution used to protonate the films. At pH 7, the polyaniline films exhibited a mostly disordered structure, with small 2–10 nm particles visible. Protonation at pH 5 to pH 3 resulted in partial agglomeration of the primary particles into larger bundles, with sizes up to 75 nm. Treatment in solution pHs of 2 or less resulted in films consisting of close-packed bundles of dimension 20–30 nm. The conductivity of the films exhibited a sharp rise beginning with protonation at pH 2 or less. Effective medium theory (EMT), was used to model the macroscopic conductivity of these films based on the SPM measured microscopic film structure. Using the size and size distribution of polymer micrograins or bundles in a modified EMT, we are able to obtain predicted conductivities that are close to the measured values for these films. © 1995 John Wiley & Sons, Inc.
Wake Capture, Particle Breakup, and Other Artifacts Associated with Counterflow Virtual Impaction

Counterflow virtual impaction is used to inertially separate cloud elements from inactivated aerosol. Previous airborne, ground-based, and laboratory studies using this technique exhibit artifacts that are not fully explained by the impaction theory. We have performed laboratory studies that show small particles can be carried across the inertial barrier of the counterflow by collision and/or coalescence or riding the wake of larger particles with sufficient inertia. We have also performed theoretical calculations to show that aerodynamic forces associated with the requisite acceleration and deceleration of particles within a counterflow virtual impactor can lead to breakup. The implication of these processes on studies using this technique is discussed.
Surgical techniques for long-term study of thoracic duct lymph circulation in dogs.

Abstract Two new surgical techniques for cannulation of the thoracic duct in dogs are presented. Both allow the study of the thoracic duct circulation under physiological conditions in awake and unrestrained animals.
Polyamines modulate the subcellular localization of RNA-binding protein HuR through AMP-activated protein kinase-regulated phosphorylation and acetylation of importin α1

Polyamines are required for maintenance of intestinal epithelial integrity, and a decrease in cellular polyamines increases the cytoplasmic levels of RNA-binding protein HuR stabilizing p53 and nucleophosmin mRNAs, thus inhibiting IEC (intestinal epithelial cell) proliferation. The AMPK (AMP-activated protein kinase), an enzyme involved in responding to metabolic stress, was recently found to be implicated in regulating the nuclear import of HuR. Here, we provide evidence showing that polyamines modulate subcellular localization of HuR through AMPK-regulated phosphorylation and acetylation of Impalpha1 (importin alpha1) in IECs. Decreased levels of cellular polyamines as a result of inhibiting ODC (ornithine decarboxylase) with DFMO (D,L-alpha-difluoromethylornithine) repressed AMPK activity and reduced Impalpha1 levels, whereas increased levels of polyamines as a result of ODC overexpression induced both AMPK and Impalpha1 levels. AMPK activation by overexpression of the AMPK gene increased Impalpha1 but reduced the cytoplasmic levels of HuR in control and polyamine-deficient cells. IECs overexpressing wild-type Impalpha1 exhibited a decrease in cytoplasmic HuR abundance, while cells overexpressing Impalpha1 proteins bearing K22R (lacking acetylation site), S105A (lacking phosphorylation site) or K22R/S105A (lacking both sites) mutations displayed increased levels of cytoplasmic HuR. Ectopic expression of these Impalpha1 mutants also prevented the increased levels of cytoplasmic HuR following polyamine depletion. These results indicate that polyamine-mediated AMPK activation triggers HuR nuclear import through phosphorylation and acetylation of Impalpha1 in IECs and that polyamine depletion increases cytoplasmic levels of HuR as a result of inactivation of the AMPK-driven Impalpha1 pathway.
Neonatal intensive care: Planning for services and outcomes following care*

C H A N G E S in neonatal care of highrisk infants over the past decade have led to the development of intensive care services which can best be provided in centers and by programs serving communities or regions on an organized basis. Recent findings strongIy suggest that neonatal intensive care has resulted in a decrease in the neonatal mortality rate and in a lower prevalence of serious handicapping conditions among the survivors.
Modeling War and Peace

The appropriate model of international conflict and war has been much discussed in recent years, and considerable progress has been made in modeling. Nevertheless the assumptions, conditions, and specifications for international conflict models remain eminently debatable. In the December 1986 issue of this Review, Bruce Bueno de Mesquita and David Lalman presented a generalized expected utility model of international conflict. Here Seif Hussein takes issue with their model in various particulars, aiming to perfect and strengthen the model. Bueno de Mesquita and Lalman respond.
More Chores for TOR: De Novo Ceramide Synthesis

In this issue of Cell Metabolism, Aronova et al. (2008) show that target of rapamycin complex 2 (TORC2) controls de novo ceramide synthesis in yeast by regulating the activity of ceramide synthase. This work may provide insight into how chemotherapeutic drugs increase de novo ceramide synthesis and promote cell death in humans.
Improving bilingual Japanese‐English and English‐Japanese dictionaries

Abstract Six English‐Japanese and four Japanese‐English dictionaries were examined for difficulties they might present for the non‐Japanese user. Six features in the bilingual dictionaries were found to be lacking, namely, specificity‐generality discriminations, situational protocol cross‐references, honorific and colloquial language discriminations, loan word clarifications, cultural notes, and the romanization of all entries. Numerous examples of entries causing confusion are noted in each of the six categories. Correction by a notational system and the addition of situational and social variants is proposed.
The pattern of infestation of the beach-hopper amphipod Orchestoidea corniculata , by a parasitic mite

The frequency distribution of an ectoparasitic mite, Gammaridacarus orchestoideae, on its amphipod host, Orchestoidea corniculata, was found to differ significantly from random for all monthly samples taken between October 1977 and October 1978. The negative binomial distribution provided a good fit to these aggregated distributions. The degree of aggregation was negatively correlated with the prevalence of infestation. Prevalence and intensity were highest in the winter, when the degree of aggregation was lowest, and vice-versa in the late summer. This seasonal pattern can be explained through changes in size and density of the host population, which are associated with changes in the size of the habitat of the hosts. Within each sample the host population was highly heterogeneous with regard to infestation by mites. Females carried heavier loads of mites than did males. Both prevalence and intensity were low in the post-moult stages of the moult cycle. Reproductive females showed lower prevalence and intensity of infestation than did either non-reproductive females or males. Analysis of the regression analysis of ‘mean crowding’ on mean density also indicated that aggregation stemmed from a non-random distribution of individual parasites, rather than from clumping of the infective stages of the parasite. Heterogeneity of the host population is suggested as an important cause of the aggregated distribution of the parasite population.
On the use of term associations in automatic information retrieval

It has been recognized that single words extracted from natural language texts are not always useful for the representation of information content. Associated or related terms. and comples content identifiers derived from thesauruses and knowledge bases, or constructed by automatic word grouping techniques, have therefore been proposed for text identification purposes.The area of associative content analysis and information retrievl is reviewed in this study. The available experimental evidence shows that none of the existing or proposed methodologies are guaranteed to improve retrieval performance in a replicable manner for document collections in different subject areas. The associative techniques are most valuable for restricted environments covering narrow subject areas, or in iterative search situations where user inputs are available to refine previously available query formulations and search output.
Bifunctional enzyme activity at the same active site: Competitive inhibition kinetics with 3α/20β-hydroxysteroid dehydrogenase

20 beta-Hydroxy-5 alpha-pregnan-3-one (HPO) is a competitive inhibitor of reduction by 3 alpha/20 beta-hydroxysteroid dehydrogenase (3 alpha/20 beta-HSD; E.C.1.1.1.53) of 17 beta-hydroxy-5 alpha-androstan-3-one (DHT; 3 alpha-activity; Ki = 4.6x10(-5)M), and of 6 beta-acetoxyprogesterone (6 beta-AP; 20 beta-activity; Ki = 4.34x10(-5)M). HPO and DHT inhibit affinity alkylation of 3 alpha/20 beta-HSD by 6 beta-bromoacetoxyprogesterone (6 beta-BAP). The facts that 1) enzyme 3 alpha-activity and 20 beta-activity are both competitively inhibited by HPO with practically identical Ki-values, 2) 6 beta-BAP is solely a 20 beta-activity substrate for 3 alpha/20 beta-HSD, 3) one mole of 6 beta-BAP reacts with one mole of 3 alpha/20 beta-HSD to simultaneously inactivate 3 alpha- and 20 beta-activity, and 4) inactivation of 3 alpha/20 beta-HSD by 6 beta-BAP is inhibited by DHT (a C19-steroid) or HPO (a C21-steroid), support the view that the same active site of 3 alpha/20 beta-HSD possesses both 3 alpha- and 20 beta-activity. Bifunctional activity at the same active site is considered for other steroid-specific enzymes in female mammalian reproductive systems.
The Brassica S gene family: molecular characterization of the SLR2 gene

TheS gene family of higher plants includes secreted glycoprotein-encoding genes and transmembrane protein kinase-encoding genes all of which share sequence similarity to theS-locus genes ofBrassica. In our continuing effort to understand the structural and functional diversification of this gene family inBrassica, we analyzed theS-locus-relatedSLR2 gene fromB. oleracea andB. campestris. SLR2 is a flower-specific gene that exhibits a high degree of sequence similarity to theS-locus genes derived from theS 2 self-incompatibility haplotype. We present data which suggest that theSLR2 gene encodes a secreted protein as predicted from its nucleotide sequence. However, unlike other secreted glycoprotein-encoding members of theS gene family, the gene contains a 591 base-pair intron at or near its 3′ terminus. Based on this structure, we propose that this gene arose prior to speciation by partial duplication of an ancestral gene similar in structure to theS-locus-linkedSRK (S ReceptorKinase) gene. The high degree of variability inSLR2 transcript levels noted in differentBrassica strains was found to be correlated with the segregation of anSLR2 polymorphism, whereby a mutatedSLR2 allele containing a duplication within the promoter region directs low expression. The implications of these findings forSLR2 gene function are discussed.
Electrosurgical destruction of a gastric polyp

The electrosurgical destruction of a gastric adenoma in a small hiatus hernia obviated the need for a thoracotomy. This technic should be of great value in the poor-risk patient.
The Materiality of the Internet

The Internet is a technological construction with a magnitude and scope comparable to the hydroelectric dams, railroads, aircraft, and electric power systems of an earlier era. Yet, it has no obvious physical manifestation--no physical object we can point to that obviously and unambiguously represents it. This article suggests some of the reasons why that is and whether a physical essence is important in defining large-scale technological systems.
Effectors increase the affinity of ADP-ribosylation factor for GTP to increase binding.

Abstract The stoichiometry of the binding of GTP to ADP-ribosylation factor (ARF) proteins, normally quite low at ∼0.05 mol/mol protein, was found to increase to a maximum of 1 mol/mol in the presence of effectors. The mechanism of this action was found to result from the ability of these effectors to increase the affinity of ARF for activating guanine nucleotide triphosphates. The existence of a conformation of ARF with low affinity (>100 μm) for GTP is proposed. The actions of effectors to increase the equilibrium binding of GTP is interpreted as evidence that these same effectors interact with and modulate the affinity of the inactive ARF for GTP. A new model for these interactions among ARF, effectors, and GTP is proposed, and a preliminary test in cells is supportive of these observations with relevance to signaling in cells.