cssi/SciSciGPT-SciSciNet huggingface dataset:
Graduate student confidence following a for-credit systematic review course pilot.

Background : In 2015, librarians at Purdue University began fielding requests from many disciplines to consult or collaborate on systematic review projects, and in 2016, health sciences librarians led the launch of a formal systematic review service. In 2019, Purdue University Libraries was reorganized as the Libraries and School of Information Studies (PULSIS) and assigned its own course designation, ILS. The increase in calls for systematic review services and the ability to teach ILS courses inspired the development of a credit-bearing ILS systematic review course. Case presentation : We designed, taught, and assessed a one-credit systematic review course for graduate students, using a backward-design course development model and applying self-determination theoretical concepts into lessons, assignments, and assessments. Using qualitative pre- and post-assessments, we discovered a variety of themes around student motivations, expectations, and preferences for the course. In quantitative post-class assessments, students reported improved confidence in all systematic review processes, with the highest confidence in their ability to choose and use citation management managers, describe the steps in the systematic review process, and understand the importance of a reproducible and systematic search strategy. Conclusions: We considered our pilot a success. Next steps include testing 2- and 3-credit- hour models and working to formally integrate the course into departmental and certificate curriculums. This case report provides a model for course design principles, learning outcomes, and assessments that librarians and library administrators can use to adjust their systematic review services.
An Infant with Failure to Thrive and Hypotonia

A 10-week-old female infant is admitted to the inpatient pediatric service with failure to thrive and hypotonia. She was born at 41 weeks of gestation via uncomplicated spontaneous vaginal delivery. Her Apgar scores were 7 and 9 at 1 and 5 minutes, respectively. The pregnancy had been complicated by intrauterine growth restriction. Maternal prenatal laboratory results were unremarkable except for group B Streptococcus positivity; the mother was treated adequately with penicillin during labor. The infant’s birth measurements were as follows: weight 3.48 kg (72nd percentile), length 48.5 cm (33rd percentile), and head circumference 35 cm (80th percentile). She had a routine newborn hospital stay, breastfed well with appropriate voiding and stooling, and was discharged 2 days after birth. On the day of discharge, her weight was 3.30 kg (56th percentile). Result of her newborn state screening was normal. The infant was able to regain her birthweight by 2 weeks of age, but by 8 weeks she required prolonged effort to ingest suboptimal volumes of formula (80 kcal/kg per day). She also demonstrated poor tone and a delay in early gross motor milestones. On current presentation at 10 weeks of age, her weight is 4.36 kg (3rd percentile). Physical examination findings are significant for …
A Comparison of Auditory and Visual Representations of System Confidence to Support Trust Specificity, Attention Management, and Joint Performance in Human-Machine Teams

Breakdowns in human-robot teaming can result from trust miscalibration, i.e., a poor mapping of trust to a system’s capabilities, resulting in misuse or disuse of the technology. Trust miscalibrati...
Evaluation of a Virus-like Replicon Particle Vaccine Expressing Proteins of Swine Influenza Virus in Pigs With and Without Maternally Derived Antibodies

A major hurdle to swine influenza vaccination of young piglets is maternal antibody interference. This interference is transient as it disappears when pigs reach about 3 months of age. We vaccinated piglets without and with interfering maternal antibody using a recombinant vector vaccine. In the absence of interfering maternal antibody, the vaccine was effective in inducing a strong immune response and greatly reduced the amount of virus. However, this same recombinant vaccine was not effective when interfering maternal antibodies were present. We are currently trying a higher dose of vaccine and different genes from SIV in hopes we can overcome this maternal antibody. Preliminary data from these new studies are promising.
Vasopressin Antagonists in Physiology and Disease

Abstract Hyponatremia is the most common electrolyte abnormality in hospitalized patients occurring in as many as 15%–30% of patients. It can present acutely or chronically. The hyponatremia has been reviewed elsewhere extensively but includes simple strategies such as free water restriction as well as more emergent measures such as the administration of hypertonic (3%) saline. In the last decade a new class of drugs that target the V2 receptor have emerged and put into clinical use. The objectives of this chapter are (1) to review the control of vasopressin release with emphasis on inhibitory pathways and (2) to review the role of vasopressin antagonists in water-retaining disorders.
Abstract W P358: Rate of “Non-Go Activation” of a High Volume Stroke Center Neuroendovascular Team during the “After Hours”/On-Call Period: Exploring the Financial Impact to an Acute Stroke Program

Background and Purpose: Timely reperfusion in large vessel occlusion strokes (LVOS) is crucial to achieving optimal functional outcomes. Acute neurointerventional therapy requires a team of individuals be assembled and ready as soon as the workup is completed and the patient is deemed an eligible and appropriate thrombectomy candidate. On occasion, the endovascular on call team is activated but the patient is subsequently determined ineligible for interventional therapy. We aimed to explore the frequency and financial impact of on-call neuroendovascular team activation when the procedure is a “Non-Go” situation and to determine its impact on the operating budget of an acute endovascular stroke program. Methods: From February-July 2014, information was collected on all instances of the neuroendovascular team being activated during the “After Hours”/On-Call period (defined as: weekdays 7PM-7AM and weekends e.g. Fri 7PM-Mon7AM) but a procedure not done due to patient ineligibility. The information collected included patient demographics, date and time of the activation, and reason why the procedure was not performed. Results: During the five month data collection period, there were 12 occasions of “Non-Go Activation” of the Neuroendovascular Team during “After Hours”. Three patients (25%) were randomized to IV tPA only in a clinical trial, four patients (33%) had marked improved symptoms and/or no-occlusion on CT angiography, and five patients (42%) had large core on initial imaging. During this same period, a total of 70 thrombectomies were performed for a ratio 5.8 overall thrombectomies for every “Non-Go After Hours” activation which seems to be a financially viable model. Conclusions: The “stand-by strategy” for the neuroendovascular team for selected stroke transfers and emergency room cases is justifiable based on the need for rapid reperfusion in LVOS. The extra burden on the “on-call” personnel is acceptable and the extra costs represent a relatively small fraction of the treatment expenses.
Insulin receptors of chicken liver and brain

Receptors on membranes of chicken liver and brain bound porcine 125I-insulin in a specific and temperature-dependent manner. Competition with unlabeled insulin derivatives exhibited typical insulin potency ratios, i.e. chicken > porcine insulin > human proinsulin (2.1/1/0.02). Apparent binding affinity was higher in brain with a 50% inhibition of tracer binding of 1.3 ± 0.2 nM porcine insulin as compared to 2.8 ± 0.3 nM in liver. The apparent molecular mass of the 125I-insulin cross-linked α subunit of the insulin receptor was 139 ± 2 kDa for chicken liver and 127 ± 2kDa for chicken brain. These molecular masses were similar to those of rat liver and brain insulin receptors. Neuraminidase treatment of the cross-linked insulin receptor increased the mobility of the α subunit from liver but did not affect that from brain, suggesting a difference in the glycosylation of the chicken brain α subunit as previously described in the rat. Despite this change, both receptors could be purified on wheat germ agglutinin (WGA) chromatography after Triton solubilization. In the presence of CTP and vanadate (phosphatase inhibitors) insulin-stimulatable tyrosine-specific phosphorylation of exogenous substrates was demonstrated with chicken liver and brain receptors. The reaction was dependent on Mg2+ and Mn2+. As noted with other insulin receptors, the best artificial substrate for phosphorylation was poly(Glu, Tyr)4: 1. In both chicken liver and brain the smallest effective insulin dose as well as maximal stimulation of phosphorylation of the substrate was similar to that seen with rat liver, and in all three tissues chicken insulin was more potent than porcine insulin. In chicken liver an active ATP hydrolytic activity copurified with the insulin receptors during WGA chromatography. Further purification using S-300 Sephacryl filtration or affinity (insulin-biotin-avidin) chromatography could dissociate the phosphorylation and the hydrolytic activities. Gel electrophoresis, under reducing conditions revealed β subunits with apparent Mr of 97–99 kDa in chicken liver and brain, which were phosphorylated in the presence of insulin. Similar apparent molecular masses have been described for the β subunit of rat liver receptors. These studies suggest that both chicken brain and liver insulin receptors exhibit coupling of α and β subunits with fully active tyrosine kinase and that the structural difference of the brain insulin receptor is widespread and phylogenetically old.
Advances and challenges in treatment and prevention of ischemic stroke

We review recent advances in the treatment and prevention of acute ischemic stroke, including the current state of endovascular therapy, in light of 5 randomized controlled trials published this past year. Although no benefit of endovascular therapy over intravenous (IV) recombinant tissue plasminogen activator (rt-PA) has been demonstrated, endovascular therapy is an appropriate treatment for acute ischemic stroke patients within the t-PA window who are ineligible for IV t-PA but have a large vascular occlusion. These trials reveal promises and current limitations of endovascular therapy, and comparison of reperfusion therapies remains an important area of research. One common theme is the strong association between a faster time to reperfusion, improved outcome, and reduced mortality. Primary and secondary stroke prevention trials emphasize the importance of aggressive management of medical risk factors as part of any preventative strategy. New oral anticoagulants, for example, offer cost-effective risk reduction in patients with atrial fibrillation, and may represent an opportunity for those with cryptogenic stroke. We highlight areas of unmet need and promising research in stroke, including the need to deliver proven therapies to more patients, and the need to recruit patients into clinical trials that better define the role of endovascular and other stroke therapies. Finally, improvement in strategies to recover speech, cognition, and motor function has the potential to benefit far more stroke patients than any acute stroke therapy, and represents the greatest opportunity for research in the coming century.
Multiple Forms of Cytochrome c in the Rat PRECURSOR-PRODUCT RELATIONSHIP BETWEEN THE MAIN COMPONENT Cy I AND THE MINOR COMPONENTS Cy II AND Cy III IN VIVO

Abstract 1. The heterogeneity of cytochrome c obtained in the monomeric form from different organs of rat was studied. Disc electrophoresis on polyacrylamide gel revealed the presence of four forms in heart muscle, liver, and kidney. In the kidney, the mean percentage distribution was Cy I 86.2%, Cy II 8.0%, Cy III 4.2%, and Cy IV 1.6%. 2. The rate at which radioactive iron (59Fe) is incorporated into cytochrome c of heart and kidney was followed in rats in a metabolic steady state. It was found that the isotope was taken up into Cy I at a rate which was approximately 30 times higher in the kidney than in the heart, which is comparable with the difference in the rate of DNA synthesis and cell turnover in these two organs. Furthermore, it was shown that the first fraction to become labeled was Cy I. Thus a distinct heterogeneity of 59Fe labeling of Cy I to Cy III was observed in the kidney, and the change in the degree of labeling as a function of time revealed the characteristics of a precursor-product relationship. This result supports previous observations indicating that only Cy I represents molecules synthesized by the cells, and that Cy II to Cy III are formed from Cy I by simple conversion in vivo. Based on previous studies on multiple forms of bovine heart cytochrome c, as well as on the conversion of rat kidney Cy I in vitro, it is concluded that the chemical basis for the in vivo conversion is a deamidation of asparagine or glutamine residues, or both. 3. The "true" life span of cytochrome c in the kidney was calculated to be approximately 80 days when based upon the conversion of Cy I into Cy II to Cy III. This value is in good agreement with the rate of conversion as determined in vitro (t½ = 95 days) at 37° and in an electrolyte solution corresponding to the intracellular fluid. From a functional point of view, however, the life span is even longer since Cy III also is capable of electron transfer in biological systems, even though it is less efficient than Cy I and Cy II. 4. The results are discussed in relation to the more general problems concerning the determination of protein turn-over within mammalian tissues. It is stressed that, when dealing with enzymes, one has to differentiate between a physicochemical and a functional turnover, since the rates of these two processes are not necessarily the same.
Patterns of CaCO3 deposition in the eastern tropical Pacific Ocean for the last 150 kyr: Evidence for a southeast Pacific depositional spike during marine isotope stage (MIS) 2

[1] We constructed biogenic mass accumulation rate (MAR) time series for eastern Pacific core transects across the equator at ~105� and ~85� W and along the equator from 80� to 140� W. We used empirical orthogonal function (EOF) analysis to extract spatially coherent patterns of CaCO3 deposition for the last 150 kyr. EOF mode 1 (51% variance) is a CaCO3 MAR spike centered in marine oxygen isotope stage 2 (MIS 2) found under the South Equatorial Current. EOF mode 2 (19% of variance) is high north of the equator. EOF mode 3 (9% of variance) is an east-west mode centered along the North Equatorial Counter Current. The MIS 2 CaCO3 spike is the largest event in the eastern Pacific for the last 150 kyr: CaCO3 MARs are 2–3 times higher at 18 ka than elsewhere in the record, including MIS 6. It is caused by high CaCO3 production rather than minimal dissolution. EOF 2, while it resembles deep water flow patterns, nevertheless, shows coherence to Corg deposition and is probably also driven by CaCO3 production. INDEX TERMS: 4267 Oceanography: General: Paleoceanography; 1615 Global Change: Biogeochemical processes (4805); 1030 Geochemistry: Geochemical cycles (0330); 3022 Marine Geology and Geophysics: Marine sediments—processes and transport; KEYWORDS: late Pleistocene, paleoproductivity, Pacific, calcite, biogeochemistry, carbon cycle
Mutations in recombinational repair and in checkpoint control genes suppress the lethal combination of srs2Delta with other DNA repair genes in Saccharomyces cerevisiae.

The SRS2 gene of Saccharomyces cerevisiae encodes a DNA helicase that is active in the postreplication repair pathway and homologous recombination. srs2 mutations are lethal in a rad54Δ background and cause poor growth or lethality in rdh54Δ, rad50Δ, mre11Δ, xrs2Δ, rad27Δ, sgs1Δ, and top3Δ backgrounds. Some of these genotypes are known to be defective in double-strand break repair. Many of these lethalities or poor growth can be suppressed by mutations in other genes in the DSB repair pathway, namely rad51, rad52, rad55, and rad57, suggesting that inhibition of recombination at a prior step prevents formation of a lethal intermediate. Lethality of the srs2Δ rad54Δ and srs2Δ rdh54Δ double mutants can also be rescued by mutations in the DNA damage checkpoint functions RAD9, RAD17, RAD24, and MEC3, indicating that the srs2 rad54 and srs2 rdh54 mutant combinations lead to an intermediate that is sensed by these checkpoint functions. When the checkpoints are intact the cells never reverse from the arrest, but loss of the checkpoints releases the arrest. However, cells do not achieve wild-type growth rates, suggesting that unrepaired damage is still present and may lead to chromosome loss.
Measles virus entry inhibitors: a structural proposal for mechanism of action and the development of resistance.

Previously, we developed a panel of nonpeptidic compounds specifically preventing fusion of the measles virus (MV) with target cells at IC50 values of 0.6−3 μM. Mutations in the MV fusion protein (MV F) that render resistance to these blockers were described. The structural basis for both inhibition and resistance was unclear in the earlier work because of the availability of a structural model for only the postfusion conformation of MV F. We have now developed structural models for both pre- and postfusion conformers of the latter protein trimer. The models allow investigation of the large-scale conformational changes occurring in the MV fusion machinery and, in conjunction with antisera binding studies, provide a rationale for how inhibitors may arrest a conformational intermediate by interfering with the formation of interactions between the heptad repeat B (HR-B) linker and DIII domains. The models also show that resistance to inhibition can be explained by a predicted destabilizing effect of the muta...
Judicial systems in contact: access to justice and the right to interpreting/translating services among the Quichua of Ecuador

The Quichua of Ecuador, along with other indigenous peoples of Latin America, have been struggling to attain the right to use their ancestral language and their traditional ways of administering justice in an effort to gain greater autonomy in a variety of sociopolitical spheres of life. Based on interviews with 93 Ecuadorians — judges, magistrates, lawyers, justices of the peace, interpreters, translators, and local and national political leaders — the study finds an ideological splintering of views on this subject. Among the disparate Quichua communities and among State justice providers (largely comprising the hegemonic mestizo/blanco sector of society) there is a lack of agreement on how justice is to be carried out and what role the Quichua language should play in it. Despite the heterogeneity of views, however, there is tacit agreement on one de facto language policy, namely, the use of untrained, ad hoc interpreters in judicial settings.
Equity, Efficiency, and Advantageous Randomness

The argument that seeks to establish the existence of a tradeoff between equity and efficiency relies on the consideration of problems of incentives. It is derived from the Pareto optimality of a competitive general equilibrium, which, in turn, depends on the assumption of universality of markets. In situations involving uncertainty, the universality of markets requires that all economic agents be perfectly informed about the probability of occurrence of various contingencies. I shall look at the dependence between equity and efficiency in a context where the latter assumption fails-the system of markets is incomplete-and I shall demonstrate that, under plausible conditions, equity promotes efficiency. The intuition is clear: Equity economizes on the information necessary to attain an efficient allocation. Efficiency in the allocation of wealth requires that individuals be able to transfer revenue across different states of nature. In the presence of uncertainty about future earnings, however, if the individual himself is the only one who knows the "true" distribution of this random variable, the problem of adverse selection arises., An individual whose future income will be low with high probability has an incentive to purchase the insurance policy designed for another individual whose future earnings are likely to be high. If the two individuals are indistinguishable during the contracting period (i.e., no differential premium is possible), and if the payment to be made can be a function only of realized income, the second individual will not be able to allocate his wealth in an efficient manner. Consequently, if he is risk averse, he may find it preferable to have an income stream with lower mean, but with the possibility of insuring against any variance. I shall construct a model to demonstrate that the situation described above can indeed occur: In the presence of adverse selection, income transfers may be desirable to all, even when extended to the point of eliminating any differences in the distribution of income. The term income redistribution is employed here in a specific
Coronary abscess in an adolescent with a structurally normal heart.

![Figure][1] ![Figure][1] [Video 1][2] Apical four chamber echoc¹ardiogram showing cystic-appearing lesion in the region of the left circumflex artery. ![Figure][1] [Video 2][3] Apical four chamber cardiac MR showing cystic-appearing lesion in the region of the left
Reverse-Time Migration = Generalized Diffraction Stack Migration

The standard reverse-time migration (RTM) algorithm is usually described as zero-lag correlation of the backprojected data with the source wavefield. The data are backprojected by a finite-difference algorithm, where each trace acts as a source-time history of a point source at the geophone location. This is a simple and easily understood migration method, but appears inflexible to improvement by the usual Kirchhoff tricks such as obliquity factors, first-arrival restrictions, angle-dependent truncation of data aperture or intrinsic anti-aliasing filters. In this paper, I reformulate the equations of reverse-time migration so that they can be interpreted as summing data along a series of hyperbola-like curves, each one representing a different type of event such as a reflection or multiple. This is a generalization of the familiar diffraction-stack algorithm where the migration image at a point is a sum of data along an appropriate hyperbolalike curve. For this reason I name this reformulation generalized diffraction stack migration (GDM). This formulation breathes new life into RTM, including a more efficient form of RTM denoted as wave-equation wavefront migration, a means for computing the exact RTM operator from RVSP data, a common-offset migration scheme for RTM, and the ability to apply Kirchhoff filtering tricks like obliquity factors and anti-aliasing filters to RTM operators. The caveat is that the full-blown GDM can be computationally more expensive than standard RTM, but reduced versions can make it more efficient
Path-Star Ramsey numbers

Abstract Let f ( m , n ) be the least integer N such that for every graph G with N vertices, either G contains a path of m vertices or the complement of G contains a vertex of degree at least n . This paper determines f ( m , n ) for all m , n .
Axial isomer and ESR spectra of the steroid spin label, 3-doxyl-5α-cholestane

Abstract The ESR spectra of the axial isomer of the steroid spin label 3-doxyl-5α-cholestane has been obtained by computer subtraction of the equatorial isomer from a partially purified mixture of the two isomers. The 14 N coupling constant is 15.03 ± 0.05 G in CDCl 3 at room temperature. The proton hyperfine splittings are only partially resolved. The assignment of these splittings is made by synthesizing a number of spin label analogs and comparing their hyperfine patterns and the corresponding computer simulations.
Use of statistical decision rules for evaluating laboratory animal carcinogenicity studies

In the evaluation of long-term rodent carcinogenicity studies, many different tumor sites and types are evaluated, which may increase the likelihood of a statistical false positive. To deal with this issue, a number of statistical decision rules have been proposed that take into account multiple comparisons. This paper discusses the various types of decision rules and evaluates the factors that may lead to different interpretations of experimental results. These concepts are illustrated by examining the statistical decision procedures used by three analysts to evaluate the results of 25 long-term rodent carcinogenicity studies carried out by the National Cancer Institute. Agreement among these decision rules is shown to be greater than originally reported. It is also concluded that while the application of statistical decision rules may be of value in some instances to guard against statistical false positives, the final interpretation of the data should be based on biological as well as statistical considerations. Thus, statistical decision rules should not be employed as a substitute for sound scientific judgment in the overall evaluation of these experiments.
Meso-2,3-dimercaptosuccinic acid induces calcium transients in cultured rhesus monkey kidney cells.

Abstract The maintenance of intracellular Ca 2+ homeostasis is critical to many cellular functions that rely on the calcium ion as a messenger. While attempting to characterize the effects of lead on intracellular calcium levels ([Ca 2+ ] i ) in LLC-MK 2 Rhesus Monkey kidney cells, we observed that treatment with the metal chelating drug, meso -2,3-dimercaptosuccinic acid (DMSA) evoked transient increases in [Ca 2+ ] i . Changes in [Ca 2+ ] i were monitored using the Ca 2+ indicator dye Fura-2 and a dual wavelength fluorescence imaging system. In the presence of 2 mM extracellular Ca 2+ , DMSA treatment caused a concentration-dependent (15–500 μM) transient increase in [Ca 2+ ] i returning to baseline levels within 30–60 s. Pharmacologic concentrations of DMSA (30 μM) stimulated a three-fold increase in [Ca 2+ ] i , which was spatiotemporally comparable to Ca 2+ transients induced by other calcium agonists. Depletion of inositol trisphosphate (IP 3 )-sensitive [Ca 2+ ] i stores with the smooth endoplasmic reticulum calcium-ATPase (SERCA) inhibitor thapsigargin did not prevent DMSA-elicited increases in [Ca 2+ ] i , suggesting that Ca 2+ mobilized by DMSA was either extracellular or from an non-IP 3 releasable Ca 2+ pool. Treatment with glutathione, cysteine, or 2-mercaptoethanol caused similar but not identical calcium transients. Adenosine-5′-trisphosphate (ATP) also elicited transient increases in [Ca 2+ ] i similar to those of DMSA. No transient increases in [Ca 2+ ] i were elicited by DMSA or ATP in the absence of extracellular calcium. These data indicate that DMSA and other sulfhydryl compounds trigger an influx of extracellular calcium, suggesting a previously unobserved and unanticipated interaction between DMSA and the Ca 2+ messenger system.
Mycobacterium tuberculosis sigF is part of a gene cluster with similarities to the Bacillus subtilis sigF and sigB operons

Abstract The Mycobacterium tuberculosis (MTB) SigF alternate sigma factor has been shown to have signficant homology to the Bacillus subtilis (BSU) stress-response sigma factor, SigB, as well as to the BSU developmental sigma factor, SigF. In this study we report that like both the BSU SigB and sigF genes, MTB sigF is preceded by an open reading frame ( usfX ) encoding a protein with significant homology to the previously described BSU anti-sigma factors, RsbW and SpollAB. Sequence analysis suggests that the usfX and sigF genes appear to be cotranscribed and translationally coupled. A second open reading frame called usfY precedes usfX , but has no significant homologues and may not be cotranscribed with the usfX and sigF . The sigF gene has been overexpressed in Escherichia coli , purified, and used to raise polyclonal antibodies. Immunoblotting demonstrates that MTB SigF is antigenically closer to BSU SigB than to BSU SigF. Fusion of the MTB sigF gene to the MTB hsp60 promoter has demonstrated that inappropriate overexpression of sigF is lethal for the slow-grower Mycobacterium bovis bacille Calmette-Guerin (BCG), but not for the rapid-grower Mycobacterium smegmatis which lacks a sigF homologue. Hence, sigF , encoding an MTB stress response, stationary phase transcription factor, is preceded by an antisigma factor homologue and is incompatible with growth when constitutively overexpressed in BCG.
Inhibition of dihydrofolate reductase gene expression following serum withdrawal or db-cAMP addition in methotrexate-resistant mouse fibroblasts.

Abstract We have used a methotrexate (MTX)-resistant mouse 3T6 cell line (M50L3), that overproduces dihydrofolate reductase (DHFR) and its mRNA by a factor of 300, to study the mechanism for turning off DHFR gene expression following withdrawal of serum factors or elevation of the intracellular level of cAMP. When resting (G0) M50L3 cells are serum-stimulated to reenter the cell cycle, the level of DHFR activity begins to increase at about the same time the cells begin synthesizing DNA. The increase in enzyme activity is preceded by increases in the synthesis rate of the enzyme, and the content and production rate of DHFR mRNA. These increases, as well as entry into S phase, are blocked when the cells are serum-stimulated in the presence of dibutyryl cyclic AMP (db-cAMP) and theophylline. In this study, we found that when these drugs were added, or the serum stimulus was withdrawn during S phase (20 h following stimulation), the subsequent increase in DHFR level was blocked. Immunoprecipitation of DHFR from pulse-labelled cells showed that both treatments led to a rapid decrease in synthesis rate of the enzyme. The effect on total protein synthesis was much less than on DHFR synthesis. In DNA-excess filter hybridization experiments, we found that the content of cytoplasmic DHFR mRNA decreased in parallel with the synthesis rate of the enzyme. This was due in part to a decrease in the production rate of DHFR mRNA relative to total mRNA. In addition, drug addition or serum withdrawal led to a significant destabilization of DHFR (as well as total) mRNA. About 85% of poly(A)(+) DHFR mRNA was associated with polysomes in resting, growing, or cAMP-treated cells, suggesting that DHFR gene expression was not controlled at the translational level under these conditions.
Structural and Functional Consequences of an Amide-to-Ester Substitution in the Selectivity Filter of a Potassium Channel

The selectivity filter of K(+) channels comprises four contiguous ion binding sites, S1 through S4. Structural and functional data indicate that the filter contains on average two K(+) ions at any given time and that these ions reside primarily in two configurations, namely to sites S1 and S3 or to sites S2 and S4. Maximum ion flux through the channel is expected to occur when the energy difference between these two binding configurations is zero. In this study, we have used protein semisynthesis to selectively perturb site 1 within the filter of the KcsA channel through use of an amide-to-ester substitution. The modification alters K(+) conduction properties. The structure of the selectivity filter is largely unperturbed by the modification, despite the loss of an ordered water molecule normally located just behind the filter. Introduction of the ester moiety was found to alter the distribution of K(+), Rb(+,) and Cs(+) within the filter, with the most dramatic change found for Rb(+). The redistribution of ions is associated with the appearance of a partially hydrated ion just external to the filter, at a position where no ion is observed in the wild-type channel. The appearance of this new ion-binding site creates a change in the distance between a pair of K(+) ions some fraction of the time, apparently leading to a reduction in the ion conduction rate. Importantly, this finding suggests that the selectivity filter of a potassium channel is optimized both in terms of absolute ion occupancy and in terms of the separation in distance between the conducting ions.
Laboratory transmission and in vivo incubation of Entomophthora muscae (Entomophthorales: Entomophthoracae) in the onion fly, Delia antiqua (Diptera: Anthomyiidae)☆

Abstract A high-moisture infection chamber was used for the in vivo transmission of Entomophthora muscae within laboratory populations of the onion fly, Delia antiqua. This cadaver-to-fly transmission procedure provided an average experimental infection rate well above 95%. Laboratory infection and temperature-dependent incubation rates of E. muscae were further examined in adult populations of D. antiqua. The time from initial exposure until host death and pathogen sporulation was accurately predicted using a second-order function of the incubation temperature. A developmental base temperature of approximately 5°C was estimated, with 105 degree-days being the average number of heat units required between host infection and death. E. muscae transmission between D. antiqua and D. platura, two insect pests typically associated with Michigan onion production, was verified under laboratory conditions.
"Nontherapy" family research and change in families: a brief clinical research communication.

This is the second interim report of an exploratory, prospective study of psychiatrically “nonlabeled” family interaction. The project focuses primarily on whole-family interaction as it progresses through time.
Spoof, Spam, Lurk and Lag: The Aesthetics of Text-Based Virtual Realities.

This paper explores communication in six text-based virtual realities through four items of jargon: spoof, spam, lurk, and lag. Research was conducted using the ethnographic tools of participant-observation and close analysis of actual interactions of MOOs (Multiple-user Object Oriented environments). Examples of how these terms are used in real-time interaction were analyzed for what they communicate about the aesthetics of interaction. Close examination suggests that these articulated aesthetics serve as rules for proper behavior, markers of experience and belonging, metaphor for poetic expression and resources for play and challenge within the community.
Issues on simulation and optimization I: robust simulation-based design of hierarchical systems

Hierarchical design scenarios arise when the performance of large-scale, complex systems can be affected through the optimal design of several smaller functional units or subsystems. Monte Carlo simulation provides a useful technique to evaluate probabilistic uncertainty in customer-specified requirements, design variables, and environmental conditions while concurrently seeking to resolve conflicts among competing subsystems. This paper presents a framework for multidisciplinary simulation-based design optimization, and the framework is applied to the design of a Formula 1 racecar. The results indicate that the proposed hierarchical approach successfully identifies designs that are robust to the observed uncertainty.
Witness to History: Introduction to Symposium on Transhistorical Catastrophe

This paper introduces the symposium on transhistorical catastrophe by illustrating some differences between American relational and French analytic approaches to the study and treatment of trauma. The work of Davoine and Gaudilliere is presented to familiarize the reader with their unique and eclectic approach to researching “madness.” Preparing for the dialogue that follows, I briefly present the discussants, who collectively take the discussion of transhistorical catastrophe from psychoanalysis through history, literature, quantum science, and linguistics.
Time to reorganize federal Earth system science and technology

My usual reaction to plans to reorganize activities in the federal government is that these are the last resort of a bureaucrat who is faced with a tough problem and has no idea how to solve it. However, this may be the time to consider seriously a reorganization that would assemble key elements of Earth-oriented science and technology into a single federal agency. This is not a new idea, as proposals to achieve this goal have been formulated in the past and wiring diagrams for a new agency have been developed. These proposals have faded away in the face of resistance to substantial structural change that characterizes the federal bureaucracy.
Takeoff and landing analysis methodology for an airbreathing space booster

Abstract This study developed methods and a general computer model for analyzing the guidance, automatic control, and runway performance of a large horizontal takeoff and landing (HTOL) airbreathing space booster. The model treats vehicle translation and rotation during ground run, transition, climb out, descent, and flare. Guidance and automatic control equations were developed for elevator rate and throttle position commands. A commercial airplane with similar takeoff weight was analyzed and compared with the HTOL space booster takeoff and landing characteristics. The study shows that the space booster configuration analyzed in this work can potentially use the same type of runways as current airplanes use.
Differential metabolism of dehydroepiandrosterone sulfate and estrogen conjugates by normal or malignant AXC/SSh rat prostate cells and effects of these steroid conjugates on cancer cell proliferation in vitro

Abstract Normal AXC/SSh rat ventral prostate and clonally derived AXC/SSh rat prostate cancer cells were evaluated for ability to metabolize estrone sulfate (E 1 S), estrone glucuronide (E 1 G), or dehydroepiandrosterone sulfate (DHEAS). Both normal and malignant prostate cells converted E 1 S to estrone. Neither normal nor malignant prostate cells had significant ability to metabolize DHEAS to DHEA, indicating differential specificity of prostate sulfatases(s) for estrogen and androgen sulfates. Both normal and neoplastic prostate cells possess β-glucuronidase which hydrolyzed E 1 G to estrone. To assess potential physiologic consequences of these enzymatic activities, we determined the effect of steroid conjugates on in vitro proliferation of selected clonal lines of AXC/SSh rat prostate cancer cells. DHEAS, 10 −6 to 10 −9 M in decade intervals, did not affect in vitro proliferation of AXC/SSh prostate cancer cells; however, 10 −5 M DHEAS decreased in vitro proliferation of these cells. Neither E 1 S nor E 1 G, 10 −5 to 10 −9 M in decade intervals, affected in vitro proliferation of AXC/SSh prostate cancer cells. These findings suggest that low residual levels of steroid conjugates, which are not removed by charcoal stripping of serum, do not affect demonstrated in vitro androgen modulation of AXC/SSh rat prostate cancer cell proliferation.
Biological basis for space-variant sensor design II: implications for VLSI sensor design

ABSTRACT We analyze the characteristics of a synthetic sensor comparable, with respect to field width and resolu-tion, to the primate visual system. We estimate that 150,000-300,000 pixels are sufficient using a loga-rithmic sensor geometry, and demonstrate that this calculation is consistent with known characteristicsof biological vision, e.g. the number of fibers in the optic nerve. To obtain the field width and resolu- tion of the primate eye with a uniform sensor requires between iO—iO' times the number of pixelsestimated for the comparable log sensor. Another interesting observation is that the field width andresolution of a conventional 512x512 sensor can be obtained with around 5000 pixels using the loggeometry. We conclude with consideration of the prospects for achieving human-like performance with contemporary VLSI technology and briefly discuss progress on space-variant VLSI sensor design. 1. Introduction In a companion paper, we summarized many of the global architectural parameters of human spatial vision ina model which utilizes the conformal mapping associated with the complex logarithm. In this paper, we review thespace complexity of space-variant sensors incorporating the logarithmic geometry. Based on the log-geometry sen-sor model of the primate eye, we can determine the characteristics of a synthetic sensor which would be necessary
Geophysics at Katmai: Geophysical expedition to Novarupta Volcano, Katmai National Park, Alaska

The great eruption of 1912 in the Aleutian Range of Alaska (Figure 1) is exceptional for both its size and relative simplicity. It was the largest eruption of this century and the largest rhyolitic outburst in almost 20 centuries. The 60-hour, 30-km3 (ejecta volume) eruption produced extensive fallout deposits, an ash-flow sheet that gave rise to the Valley of Ten Thousand Smokes, and the 3-km-diameter Mt. Katmai caldera. Because magma reached the surface through uniform nonvolcanic basement and the vent underwent little or no collapse (unusual for such a large event), the site provides an ideal target for surface geophysical and subsurface coring exploration of structures and conditions produced by explosive volcanism [Panel on Volcanic Studies at Katmai, 1989]. A project to investigate upper crustal magmatic processes at Katmai is part of the U.S. Continental Scientific Drilling Program [Eichelberger and Hildreth, 1986]. The surface studies phase of this project was undertaken last summer and preliminary results are now emerging.
Preseismic rupture progression and great earthquake instabilities at plate boundaries

We present a procedure for modeling the initially quasi-static upward progression of a zone of slip from some depth in the lithosphere toward the earth's surface, along a transform plate margin, culminating in a great crustal earthquake. Stress transmission in the lithosphere is analyzed with a generalized Elsasser model, in which elastic lithospheric plates undergo plane stress deformation and are coupled by an elementary foundation model to a Maxwellian viscoelastic asthenosphere. Upward progression of rupture over a finite length of plate boundary, corresponding to a seismic gap along strike, is analyzed by a method based on the ‘line-spring’ concept, whereby a two-dimensional antiplane analysis of the upward progression provides the relation between lithospheric thickness-averaged stress and slip used as a boundary condition in the generalized Elsasser plate model. The formulation results in a nonlinear integral equation for the rupture progression as a function of time and distance along strike. A simpler approximate single degree of freedom analysis procedure is described and shown to lead to instability results that can be formulated in terms of the slip-softening slope at the boundary falling below the elastic unloading stiffness of the surroundings. The results also indicate a delay of ultimate (seismic) instability due to the stiffer short versus long time asthenospheric response and predict a final period of self-driven creep toward instability. The procedures for prediction of rupture progression and instability are illustrated in detail for an elastic-brittle crack model of slip zone advance, and parameters of the model are chosen consistently with great earthquake slips and stress drops. For example, an effective crack fracture energy of the order 4×106 J/m2 at the peak, 7 to 10 km below surface, of a Gaussian bell-shaped distribution of fracture energy with depth, with variance of the order 5 km, simulating strength build-up in a seismogenic layer, leads to prediction of nominal seismic stress drops of 30 to 60 bars and slips of 2 to 5 m in great strike slip earthquake ruptures breaking 100 to 400 km along strike. Precursory surface straining in the self-driven stage is predicted to proceed at a distinctly higher rate over time intervals beginning 3 to 10 months before such an earthquake, this interval being greater for longer distances along strike over which the preseismic upward rupture progression takes place.
Export Controls and the Tensions Between Academic Freedom and National Security

In the U.S.A., advocates of academic freedom—the ability to pursue research unencumbered by government controls—have long found sparring partners in government officials who regulate technology trade. From concern over classified research in the 1950s, to the expansion of export controls to cover trade in information in the 1970s, to current debates over emerging technologies and global innovation, the academic community and the government have each sought opportunities to demarcate the sphere of their respective authority and autonomy and assert themselves in that sphere. In this paper, we explore these opportunities, showing how the Social Contract for Science set the terms for the debate, and how the controversy turned to the proper interpretation of this compact. In particular, we analyze how the 1985 presidential directive excluding fundamental research from export controls created a boundary object that successfully demarcated science and the state, but only for a Cold War world that would soon come to an end. Significant changes have occurred since then in the governance structures of science and in the technical and political environment within which both universities and the state sit. Even though there have been significant and persistent calls for reassessing the Cold War demarcation, a new institutionalization of how to balance the concerns of national security and academic freedom is still only in its nascent stages. We explore the value of moving from a boundary object to a boundary organization, as represented in a proposed new governance body, the Science and Security Commission.
Defining and Reporting Diarrhea in Tube-Fed Patients—What a Mess! D. Z. BLISS, P. A. GUENTER, R. G. SETTLE American Journal of Clinical Nutrition 55:753-759, 1992

The purpose of this study is to document the effect that various definitions of diarrhea have on its reported incidence in tube-fed patients. Following a group of 29 patients who were tube-fed for at least 5 days (median duration of feeding, 13 days), the investigators prospectively monitored the occurrence of diarrhea according to each of eight definitions: ≥1, ≥2, ≥3, ≥4 liquid stools/ day; ≥3 stools/day; ≥4 stools/day; ≥4 stools/day for 2 days; and ≥5 stools/day. None of the definitions incorporated measurements of either stool weights or volumes. Because treatment with antibiotics and the presence of hypoalbuminemia have been associated with diarrhea in some reports, the investigators took those into account. Sixty-six percent of the patients (19 patients) were treated with antibiotics and only 7% (2 patients) had serum albumin levels <26 g/L; the mean serum albumin level of the remaining 27 patients was 34 g/L. Only 10% (3 patients) were in critical care units. Because duration of monitoring would be...