cssi/SciSciGPT-SciSciNet huggingface dataset:
The Phosphatidylinositol 3-Kinase/Akt Cassette Regulates Purine Nucleotide Synthesis

The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is highly conserved throughout evolution and regulates cell size and survival and cell cycle progression. It regulates the latter by stimulating procession through G1 and the G1/S phase transition. Entry into S phase requires an abundant supply of purine nucleotides, but the effect of the PI3K/Akt pathway on purine synthesis has not been studied. We now show that the PI3K/Akt cassette regulates both de novo and salvage purine nucleotide synthesis in insulin-responsive mouse mesenchymal cells. We found that serum and insulin stimulated de novo purine synthesis in serum-starved cells largely through PI3K/Akt signaling, and pharmacologic and genetic inhibition of PI3K/Akt reduced de novo synthesis by 75% in logarithmically growing cells. PI3K/Akt regulated early steps of de novo synthesis by modulating phosphoribosylpyrophosphate production by the non-oxidative pentose phosphate pathway and late steps by modulating activity of the bifunctional enzyme aminoimidazole-carboxamide ribonucleotide transformylase IMP cyclohydrolase, an enzyme not previously known to be regulated. The effects of PI3K/Akt on purine nucleotide salvage were likely through regulating phosphoribosylpyrophosphate availability. These studies define a new mechanism whereby the PI3K/Akt cassette functions as a master regulator of cellular metabolism and a key player in oncogenesis.
Fat Metabolism in Higher Plants. XXXVII. Characterization of the β-Oxidation Systems From Maturing and Germinating Castor Bean Seeds

In the maturing castor bean seed (Ricinus communis), maximum beta-oxidation appears at 28 days after flowering and in the germinating seed, 4 days after germination. Highest specific activities for both beta-oxidation systems and their component enzymes are associated with cytosomal particles banding at a density of 1.25 g/ml in a sucrose gradient. Substrate specificity studies indicate that of several fatty acids, ricinoleate is oxidized most rapidly by the preparation from the maturing seed (28 days after flowering) while palmitate and linoleate are oxidized most rapidly by extracts obtained from tissue germinated for 4 days. The beta-oxidation activities observed in both systems reflect the expression of activity of at least 3 of the component enzymes, crotonase, beta-hydroxyacyl dehydrogenase and beta-keto-thiolase, which rise and fall co-ordinately. Acyl thiokinase does not appear to play a limiting role in regulating beta-oxidation per se under the conditions employed here.
Phantom limb: amputation, embodiment, and prosthetic technology

In Phantom Limb, Crawford examines the modernization of the USA's amputation industry from the late nineteenth century to the early twenty-first century. Using medical and scientific texts and inte...
Multivariate Locally Weighted Polynomial Fitting and Partial Derivative Estimation

Nonparametric regression estimator based on locally weighted least squares fitting has been studied by Fan and Ruppert and Wand. The latter paper also studies, in the univariate case, nonparametric derivative estimators given by a locally weighted polynomial fitting. Compared with traditional kernel estimators, these estimators are often of simpler form and possess some better properties. In this paper, we develop current work on locally weighted regression and generalize locally weighted polynomial fitting to the estimation of partial derivatives in a multivariate regression context. Specifically, for both the regression and partial derivative estimators we prove joint asymptotic normality and derive explicit asymptotic expansions for their conditional bias and conditional convariance matrix (given observations of predictor variables) in each of the two important cases of local linear fit and local quadratic fit.
Analytic models for the equilibrium behavior of binary mixtures in the presence of a solid surface

Analytical relationships are presented to predict concentration profiles for the components of a binary mixture in the presence of a solid surface. These relationships are based on a modified lattice model which accounts for interactions between the components and the surface, and interactions between components in adjacent lattice layers. Approximations are introduced to isolate the important role of two dimensionless groups in establishing the nature and extent of interphase zones. The first group is a measure of the intensity of the concentration perturbation at the surface. The second group serves as a measure of the system's ability to propagate the perturbation away from the surface. These groups contain interaction energies, the bulk concentration of the components, the degree of polymerization of each of the binary components, and temperature. Consequently, these groups provide guidelines for selecting components and processing temperatures to control the nature and extent of interphase zones next to a solid surface.
Shock-induced microdeformations in quartz and other mineralogical indications of an impact event at the Cretaceous-Tertiary boundary

Abstract The event terminating the Cretaceous period and the Mesozoic era caused massive extinctions of flora and fauna worldwide. Theories of the nature of this event can be classed as endogenic (volcanic, climatic, etc.) or exogenic (extraterrestrial causes). Mineralogical evidence from the boundary clays and claystones strongly favor the impact of an extraterrestrial body as the cause of this event. Nonmarine KT boundary claystones are comprised of two separate layers—an upper layer composed of high-angle ejecta material (shocked quartz, altered glass and spinel) and a basal kaolinitic layer containing spherules, clasts, and altered glass, together with some shocked grains. Recognition of this dual-layered nature of the boundary clay is important for the determination of the timing and processes involved in the impact event and in the assignment and interpretation of geochemical signatures. Multiple sets of shock-induced microdeformations (planar features) in quartz grains separated from KT boundary clays provide compelling evidence of an impact event. This mineralogical manifestation of shock metamorphism is associated worldwide with a large positive anomaly of iridium in these boundary clays, which has also been considered indicative of the impact of a large extraterrestrial body. Global distributions of maximum sizes of shocked quartz grains from the boundary clays and the mineralogy of the ejecta components favor an impact on or near the North American continent. Spinel crystals (magnesioferrite) occur in the boundary clays as micrometer-sized octahedra or skeletal forms. Their composition differs from that of spinels found in terrestrial oceanic basalts. Magnesioferrite crystals are restricted to the high-angle ejecta layer of the boundary clays and their small size and skeletal morphology suggest that they are condensation products of a vaporized bolide. Hollow spherules ranging up to 1 mm in size are ubiquitously associated with the boundary clays. In nonmarine sections, where a high-angle ejecta layer and an underlying kaolinitic layer can be distinguished, the spherules are found only in the kaolinitic layer. The morphologies and surface features of these spherules suggest that they are original forms, and not secondary growths or algal bodies. These impact spherules closely resemble microtektites in size and shape. All of these features of the boundary clay are uniquely associated with impact, and cannot have been formed by volcanic or other terrestrial processes.
Are consensus democracies more environmentally effective

Are consensus democracies more likely to enact environmentally friendly policies than majoritarian democracies? The relationship between democratic type and environmental effectiveness is more complex than previously assumed. What matters are not only institutions but also the nature of the policy issues, the types of institutions and veto players in the system. Four measures of effectiveness emerged from the data: mundane environmentalism; environmental taxation; conservation; and nuclear energy production. Environmental effectiveness in democratic systems differs depending upon which measure of effectiveness is examined and whether or not one looks at representational or organisational aspects of democracy.
Broadening of the parallel and perpendicular ion energy spectrum and correlation with turbulent potential fluctuations in a linear magnetized plasma

Abstract We previously reported electrostatic energy analyzer (GEA) measurements of the parallel energy distribution of ions incident on a floating target in PISCES-A [J. Cuthbertson, R. Lehmer, M. Jakubowski, S.C. Luckhardt, Bull. Am. Phys. Soc. 41 (1996) 1575]. The principal finding was that ion energy spectrum was significantly broader (6–8 eV) than the ion temperature expected from classical collision processes (Ti ≅ 2–3 eV). In this paper, we present further gridded energy analyzer measurements, and Doppler broadening measurements of ion spectral lines. Moreover, we have varied plasma conditions such that the turbulent plasma potential fluctuation amplitudes covered the range 3 eV
Clean energy technology transfer: A review of programs under the UNFCCC

This paper describes the experience andresults of programs designed tooperationalize the technology transferprovisions of the United Nations FrameworkConvention on Climate Change (UNFCCC). These programs share a common goal ofdemonstrating modalities for developedcountry parties to fulfill their obligationunder the UNFCCC to supporttechnology transfer to developing countryparties that facilitates theirparticipation in global efforts to combatclimate changes. Several related U.S.bilateral programs and programs supportedby the Climate Technology Initiative, amultilateral effort on behalf of a numberof Organization for Economic Cooperation and Development (OECD) countries, are included in thisreview. The discussion highlights a numberof common elements of the approaches ofmany of these programs as well as somedifferences. It presents case studies thatfocus on methods and results in China,Mexico, and Southern Africa, and cataloguesand describes the implementation activitiesand results that these programs haveachieved. It concludes by assessing theimplications of this experience for theinternational community as it moves forwardwith the climate change technology transferenterprise.
Determination of the pharmacokinetic profiles of insulin-like growth factor binding proteins-1 and -2 in rats

The insulin-like growth factor binding proteins (IGFBPs) are present in serum and alter the half-life of IGF-I and II in the vascular compartment. Because both IGFBP-1 and 2 have been proposed as regulators of IGF transport, we directly determined their distribution and elimination characteristics in rats. 125I-IGFBP-1 and 2 were injected into anesthetized normal rats. Multiple blood samples were drawn over time and the trichloroacetic acid precipitable radioactivity used to determine their pharmacokinetic profiles. The mean residence time for IGFBP-1 was 129 +/- 31 min and for IGFBP-2 116 +/- 24 min. The volume of distribution at steady state was 300 +/- 87 ml/kg for IGFBP-1 and 242 +/- 32 ml/kg for IGFBP-2. The elimination half-life was 120 +/- 26 min for IGFBP-1 and 144 +/- 32 for IGFBP-2. The results show that two separate methods of analysis give equivalent results for estimation of half-lives of these forms of IGFBPs and that their half-lives are substantially greater than that reported for free IGF...
Computer-aided displacement analysis of spatial mechanisms using the CH programming language

Abstract Recently, Cheng in 1993 introduced the C H programming language. C H is designed to be a superset of C with all the programming features of FORTRAN. Formulas with dual numbers can be translated into C H programming statements as easily as formulas with real and complex numbers. In this paper we will show that both formulation and programming with dual numbers are remarkably simple for analysis of complicated spatial mechanisms under the C H programming paradigm. With computational capabilities for dual formulas in mind, formulas for analysis of spatial mechanisms are derived differently from those intended for implementation in computer programming languages without dual data type. We will demonstrate some formulation and programming techniques in the C H programming paradigm through displacement analysis of the RCRCR five-link spatial mechanism. A C H program that can obtain both numerical and graphical results for complete displacement analysis of the RCRCR mechanism will be presented.
Readaptation to the sleep laboratory in insomniac subjects.

A readaptation effect to the sleep laboratory was demonstrated for insomniac subjects who returned lo the laboratory for a second series of consecutive nights after spending one week at home. This effect was similar to that seen in the initial adaptation period, i.e. REM percentage, REM min. number of REM periods, min stage 4. and percentage stage 4 were decreased on the first night upon returning to the laboratory as compared to subsequent nights. In addition, there was an increase in percentage stage 2, sleep latency, and total wake time on this first laboratory night.
Dermatitis from celery.

In an investigation into the cause of dermatitis from celery, it has been found that the responsible agent lies in the volatile oil, which is present to the extent of about 0.005% of the fresh overground portion. Long range experiments are now under way to determine if workers in the field can be desensitized by injections of the diluted oil. During the course of the examination, the marketable portions have been submitted to proximate analysis and fractionation. Mannitol was found in abundance and some of the properties of the oil have been determined.
Remote sensing of chlorophyll concentrations in the northern Gulf of Mexico

During a 17 month period (November 1978 - March 1980), phytoplankton pigment concentrations were remotely sensed in the northern Gulf of Mexico using the Coastal Zone Color Scanner (CZCS). A total of 29 CZCS orbits were processed into pigment (chlorophyll a + phaeopigments) images and then geometrically warped to a Mercator projection. A correction factor of 1.67 was applied to the pigment concentrations to correct for the tendency of the standard fluorometric method to underestimate chlorophyll a concentrations. The spatial and temporal distributions of pigment fronts were quite variable during this time series. Constant features observed throughout the pigment imagery were the entrainment of coastal waters offshore. The most extensive entrainments occurred during intrusions of the Loop Current. For the 17 month survey, the mean HPLC-corrected pigment concentration was 3.30 + or - 1.45 mg/cu m.
Effects of mazindol on behavior maintained or occasioned by cocaine.

Abstract The effects of mazindol, cocaine and d -amphetamine were studied in rhesus monkeys trained to self-administer cocaine, and in rats and squirrel monkeys trained to discriminate cocaine from saline. Non-contingent intravenous drug injections were administered to monkeys responding under a session consisting of a 5-min period during which lever-pressing produced food reinforcement and a 60-min session in which responding produced i.v. cocaine infusions (10 or 33 μg/kg per infusion). Acute i.v. injections of cocaine (0.1–1.7 mg/kg), d -amphetamine (0.1–1 mg/kg) and the dopamine re-uptake inhibitor mazindol (0.03–0.56 mg/kg) given 5 min before the session decreased self-administration of cocaine, but also decreased rates of behavior maintained by the presentation of food. In both rats and squirrel monkeys trained to discriminate cocaine from saline in a two-lever, food-maintained procedure, mazindol, cocaine and d -amphetamine substituted for cocaine in a dose-related manner. Despite a lack of selectivity to decrease cocaine self-administration as compared to behavior maintained by food, the present data provide some rationale for further consideration of mazindol as a potential pharmacotherapy for stimulant abuse, due to its relatively low abuse liability and cocaine-like discriminative stimulus effects.
Abstract 3696: Psychological stress inhibits, while GABA potentiates, the prevention of pancreatic cancer progression in xenografts by celecoxib

Pancreatic cancer has a poor prognosis and is associated with high levels of psychological distress. We have earlier shown that beta-adrenergic receptors, which are activated by stress neurotransmitters, regulate pancreatic cancer cells via cAMP-dependent signaling in vitro and that psychological distress promotes pancreatic cancer growth in vivo. The observation that psychological distress acts as an ancillary factor in growth promotion of pancreatic cancer have implications for cancer prevention strategies where stress initiated growth stimulus may retard the efficacy of cancer preventive regimens. Therefore this study tested the hypothesis that psychological stress inhibits the cancer preventive effects of celecoxib on pancreatic cancer progression whereas α-aminobutyric acid (GABA) which neutralizes the stress neurotransmitter stimulated cAMP signaling may potentiate the chemopreventive outcome of anti-cancer drugs. The effects of psychological distress in the absence and presence of treatment (with COX-2 inhibitor celecoxib alone / celecoxib with GABA co-adminstration) was tested in mice carrying xenograft from human pancreatic cancer cell line BxPC-3. Neuroendocrine responses (noradrenaline, adrenaline, cortisol & GABA), cancer stimulating factors (VEGF & prostaglandin PGE2) and levels of cAMP were measured by immunoassays in serum and xenograft tissue. Phosphorylation of nicotinic receptors (≥4 and α7), beta-adrenergic receptors, celecoxib targets (COX-2 & 5-lipoxygenase) and signaling proteins downstream of α-ARs were determined by semi-quantitative Western blots. The results show a significant inhibition of cancer preventive effects of celecoxib by psychological stress. By contrast, GABA significantly potentiated the preventive effects of celecoxib in this tumor model. The effector molecules of stress signaling via the cAMP pathway were downregulated by GABA and celecoxib additionally inhibited COX-2 and 5-lipoxygenase lead to significant inhibition of tumor growth in our xenografts model. Our findings identify the interruption of stress-induced c-AMP-dependent neuroendocrine stimulation as central regulator of pancreatic cancer that negatively impacts cancer prevention. In addition, our data identify the anti-stress GABA signaling as an effective adjuvant to standard interventions which in turn shows induce in the COX-2 phosphorylation and increase PGE2 level in the social stress groups which are inhibited by GABA or celecoxib or combination treatment. Better understanding in the above areas may help to develop new therapeutic for pancreatic cancer development. Grant Support: RC1CA144640 and R01CA042829 with the National Cancer Institute. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3696. doi:1538-7445.AM2012-3696
Antibodies to single-stranded and double-stranded DNA in antinuclear antibody-positive type 1-autoimmune hepatitis

To determine the significance of antibodies to single-stranded (anti-ssDNA) and double-stranded DNA (anti-dsDNA) in antinuclear antibody (ANA)-positive type 1 autoimmune hepatitis, sera from 53 patients were tested by enzyme immunosorbent assay (ELISA) and indirect immunofluorescence using the Crithidia luciliae substrate. Anti-dsDNA were detected in 18 patients (34%) by ELISA and 12 patients (23%) by the Crithidia-based assay. Twenty patients with anti-dsDNA by either assay (38%) had higher serum levels of immunoglobulin G (3971 +/- 270 mg/dL vs. 3201 +/- 247 mg/dL, P = .05) than seronegative patients. They also had human leukocyte antigen (HLA) DR4 more commonly than other patients (83% vs. 41%, P = .006) and normal subjects (83% vs. 30%, P = .00007). In contrast to patients seropositive by the Crithidia-based assay, those seropositive by ELISA failed corticosteroid therapy more commonly (24% vs. 3%, P = .04). Anti-ssDNA were found in 45 patients (85%) and they did not distinguish patients with different clinical features or outcomes. We conclude that anti-dsDNA are common in ANA-positive type 1 autoimmune hepatitis. HLA DR4 is associated with their production, and seropositivity by ELISA characterizes patients who have a poorer immediate response to corticosteroid treatment. Anti-ssDNA are common but they do not have important clinical implications.
Rates of residual disease with close but negative margins in breast cancer surgery.

Abstract Objectives A recent multidisciplinary consensus defined an adequate breast cancer margin as no ink on tumor. The purpose of this study was to analyze rates of residual disease at re-excision by margin width. Materials and methods A prospective database at a single institution was reviewed from 2000 to 2012. Institutional protocol had been to perform re-excision surgery when margins were Results There were 2520 procedures. Re-excision surgery was performed for 12% of breast conserving therapy (BCT) procedures and 2% of mastectomies; residual disease was present in 38% and 26%, respectively. The rates of residual disease for all patients with positive, 0.1–0.9 mm, and 1.0–1.9 mm margins were 40%, 38%, and 33%, respectively. Age, race, menopause status, width of closest final margin, tumor histology, hormone receptor status, triple-negative disease and presence of lymphovascular invasion (LVI) were not significantly associated with the presence of residual disease. The presence of multiple margins Median follow-up was 43 months. The five-year local recurrence rates (5-year LR) were 1.1% for mastectomy patients and 1.9% for BCT patients. Conclusions Breast cancer patients with margins of excision
Analysis of Gga Null Mice Demonstrates a Non-Redundant Role for Mammalian GGA2 during Development

Numerous studies using cultured mammalian cells have shown that the three GGAs (Golgi-localized, gamma-ear containing, ADP-ribosylation factor- binding proteins) function in the transport of cargo proteins between the trans- Golgi network and endosomes. However, the in vivo role(s) of these adaptor proteins and their possible functional redundancy has not been analyzed. In this study, the genes encoding GGAs1-3 were disrupted in mice by insertional mutagenesis. Loss of GGA1 or GGA3 alone was well tolerated whereas the absence of GGA2 resulted in embryonic or neonatal lethality, depending on the genetic background of the mice. Thus, GGA2 mediates a vital function that cannot be compensated for by GGA1and/or GGA3. The combined loss of GGA1 and GGA3 also resulted in a high incidence of neonatal mortality but in this case the expression level of GGA2 may be inadequate to compensate for the loss of the other two GGAs. We conclude that the three mammalian GGAs are essential proteins that are not fully redundant.
Clinical Teacher Preparation: A Retrospective

In this article, we explore how teacher preparation programs have developed from the mid-1800s to present day, emphasizing changes in the clinical component. Drawing from the history of teacher education from the normal schools of the 19th century to present-day interest in clinically based preparation, we first review the migration of teacher preparation from normal schools into higher education. Next we discuss how accreditation has shaped programs. We then turn our attention to major initiatives in the 1980s that explicitly focused on linking school improvement with teacher education reform—partnerships that emphasized clinical aspects of teacher preparation. Finally, we discuss efforts to enhance clinical learning, highlighting instructional strategies and issues regarding design, settings, and outcomes for programs as they work to meet challenging new accreditation standards.
ICT and road transportation safety in the United States: a case of “American exceptionalism”

This paper examines American attitudes about the role and structure of government and how those attitudes affect the safety potential of ICT-based road safety technologies. It examines these attitudes in the context of 3 current intelligent transportation systems (ITS) initiatives: IntelliDriveSM, active traffic management (ATM), and automated enforcement. It concludes that cultural attitudes have a strong influence on the acceptance of such systems, and provides suggestions for how such systems might be implemented successfully.
Design and performance evaluation of an actively compliant underwater manipulator for full-ocean depth

An underwater manipulator is described that can exhibit a wide range of compliance through a combination of mechanical design and software control and its performance characterized. The manipulator has been used in conjunction with the JASON Remotely Operated Vehicle at full-ocean depth. The major goal of the design was to produce a manipulator that can actively control the interaction forces with the work task in the hostile deep-ocean environment. The manipulator's performance has been characterized in the lab and its overall operational utility has been confirmed during tests to depths of approximately 4000 meters, including an archaeological excavation at 700 meters depth in the Mediterranean. The manipulator uses high performance brushless DC servomotors driving the joints though low-friction, zero-backlash reductions of moderate ratio consisting of cables and pulleys. Each joint is highly backdriveable and has a large range of rotation. This approach permits a variety of force control schemes such as impedance control to be implemented with no sensors other than the displacement sensors integrated with the brushless motor. It also permits high-quality torque servomechanisms to be directly implemented. This article outlines the design and illustrates the performance of a single joint in terms of friction, stiffness, and in implementing variable compliance and as a closed-loop torque servo.
Role of vitamin A in mitochondrial gene expression.

Abstract Diabetes-prone BHE/Cdb and Sprague–Dawley (SD) rats were studied with respect to mitochondrial (mt) function and mt gene expression. The BHE/Cdb rats carry mutations in the mt ATPase 6 gene that phenotype as decreased OXPHOS efficiency with subsequent development of impaired glucose tolerance. The base substitutions result in amino acid substitutions in the proton channel and this, in turn, affects the efficiency of energy capture in the ATP molecule. Feeding studies showed that BHE/Cdb rats required 10 times more vitamin E and three times more vitamin A in their diets than do normal SD rats. Vitamin A supplementation ‘normalized’ mt OXPHOS as well as increased the amount of ATPase subunit a protein in the mt compartment. Western blot analysis of retinoic acid receptors in the mitochondrial and nuclear compartments showed that these proteins were present in the mt compartment. The effect of the vitamin A supplementation plus the observation of retinoic acid receptors suggest that vitamin A functions to enhance the transcription of the ATPase 6 gene. Work with primary cultures of hepatocytes showed that not only does retinoic acid increase mitochondrial ATPase 6 gene expression but so too does the steroid hormone intermediate, dehydroepiandrosterone (DHEA). Triiodothyronine also plays a role in this process but not as an independent factor. Rather, this hormone potentiates the effects of retinoic acid and DHEA on ATPase gene expression. These results suggest that mt gene expression requires more than just the mt transcription factor A. More than likely the process requires a number of factors in much the same way as does nuclear gene expression.
Endotoxin-stimulated nitric oxide production increases injury and reduces rat liver chemiluminescence during reperfusion

Abstract Background/Aims: Nitric oxide has many physiological functions and may play an important role in modulating tissue injury. However, the mechanism of NO action in ischemia/reperfusion injury is completely unknown. This report investigates the role of NO in hepatic reperfusion injury. Methods: Rat liver was oxygenated for 30 minutes, followed by 30 minutes of ischemia, and then reperfused for 30 minutes. Perfusate was sampled for aspartate aminotransferase content, as an indication of hepatic injury, and for nitrite, an index of NO production. Spontaneous organ chemiluminescence was continuously monitored as a measure of oxyradical production. Results: NO production by the perfused rat liver was induced in vivo by pretreatment with Escherichia coli lipopolysaccharide. This induction led to an increase in hepatic injury during reperfusion that was partially ameliorated by the NO synthase inhibitor N G -monomethyl-l-arginine. Chemiluminescence during reperfusion, a measure of superoxide production in this system, was also decreased in the lipopolysaccharide-treated animals, and this effect was blunted by N G -monomethyl-l-arginine. Conclusions: These data suggest that NO may combine with superoxide formed during reperfusion to directly cause hepatocellular injury. In vitro work shows that this chemical product is the highly toxic species peroxynitrite.
The effects of various fixative‐buffer combinations on lung fine structure

A variety of fixatives, buffers and fixation procedures were compared in rat and squirrel monkey lung in an attempt to preserve optimally both the cytologic details of pulmonary parenchyma as well as the acellular alveolar lining layer. In initial experiments utilizing the fixative of Ito and Karnovsky ('68), an electron-dense deposit was observed on the alveolar surface. Experiments were carried out in an attempt to determine what component of this fixative was responsible for the reaction product observed. In addition, immersion fixation of tissue blocks was compared to the whole lung fixation method of Kikkawa ('70). Kikkawa ('70) achieved excellent preservation of the acellular alveolar lining layer by such a fixation technique. In all lungs examined, whenever a phosphate buffer was utilized with primary aldehyde fixation, an electron-dense precipitate was observed on the luminal surfaces of the type I and II pulmonary epithelial cells. Additional sites of reaction product were pinocytotic vesicles of the type I cells and membranous arrays within the alveolar lumen. Such deposits were never observed when a sodium cacodylate buffer was used. No such granules were observed in areas of lung where the acellular alveolar lining layer had been preserved. The implications of these findings with regard to lung histochemical procedures and the possible relationship of these phosphate buffer-dependent granules to the surfactant system are discussed.
Thinking aloud during problem solving: Facilitation effects

Abstract According to many cognitive psychologists, thinking aloud during problem solving does not alter task performance, but instead elucidates the cognitive processes employed by the learner. The assumption that performance is not altered while thinking aloud was questioned by three separate studies. Study 1 involved normally achieving fifth graders completing two identical sets of analogies under one of four conditions: (1) Silent/Silent; (2) Silent/Thinking Aloud; (3) Thinking Aloud/Silent; and (4) Thinking Aloud/Thinking Aloud. Analyses revealed superior performance while thinking aloud as compared to silent performance. Study 2 was designed to determine the generality of the think aloud findings across diagnostic groups, including learning disabled and developmentally handicapped. All three groups of fifth graders profited significantly from thinking aloud on both verbal and spatial analogies. Finally, Study 3 examined the generality of the think aloud findings to normally achieving and learning disabled adults. No facultative effects were experienced by adults. The theoretical and educational implications of these findings are discussed.
Stylometric classification of different translations of the same text into the same language

Quantitative stylometry of ten translations of the same Bible passage into English, followed by Ward clustering, produces a dendrogram that reflects the well-known history and intent of the translations. We conclude that quantitative stylometry combined with clustering is a useful tool for reconstructing literary history.
Determination of oxygen consumption in the albino rat.

Summary1. A method is described for determination of oxygen consumption in the rat. Its major advances are: (a) Humidity control, inducing sleep. (b) Sensitive recording method, which shows body movements on the oxygen line and makes feasible readings covering 5-minute periods.2. Values obtained in 172 determinations on 42 male rats show a decline from 771 cc/kg/hr at age 4 months and 752 cc/kg/hr at 5 months to a plateau at 6 months and maintained to at least 9 months. The average for 133 determinations on rats of 6-9 months is 692 cc/kg/hr ± 3.0 (P. E.), or 635 Cal/m2/24 hr.
Limiting distributions of homogeneous functions of sample spacings for distributions approaching the uniform distribution

X 1,...,X n are independent random variables, identically distributed over the unit interval, with common probability density function 1 + r(x)/n δ for all sufficiently large n, where δ is a positive constant, $$\int\limits_0^1 {r(x){\text{ }}dx = 0}$$ and |r″(x)| <D. V 1, ..., V n+1 are the sample spacings generated by X 1,..., X n . It is shown that in many cases, the asymptotic joint distribution of homogeneous functions of V 1,..., V n+1 can be found directly from the asymptotic joint distribution of homogeneous functions of independent exponential random variables.
Environmental enrichment enhances neurogranin expression and hippocampal learning and memory but fails to rescue the impairments of neurogranin null mutant mice.

Environmental enrichment is known to enhance hippocampal neurogenesis and cognitive functions. Neurogranin (Ng), a specific substrate of protein kinase C (PKC), is abundantly expressed in brain regions important for cognitive functions. Deletion of Ng in mice causes severe deficits in spatial learning and long-term potentiation (LTP) in the hippocampal CA1 region. These Ng−/− mice, as compared with Ng+/+, respond poorly after treatment of their hippocampal slices with agents that activate signaling molecules important for learning and memory, including Ca2+/calmodulin-dependent protein kinase II (αCaMKII), PKC, protein kinase A (PKA), extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB). In the present study, adult mice were housed in either regular home cages (control group) or more spacious cages with an exercise wheel and change of toys twice per week (enriched group) for at least 3 weeks. Enriched Ng+/+ and Ng+/− mice showed enhanced LTP in the hippocampal CA1 after high-frequency stimulation, but Ng−/− mice were affected only minimally. Behaviorally, the enriched Ng+/+ and Ng+/−, but not Ng−/− mice, performed significantly better than their respective control cohorts in Morris water maze and in step-down fear conditioning. Enriched Ng+/− mice also showed improvement in the radial arm maze. Quantitative immunoblot analyses showed that the enriched groups of all three genotypes exhibited elevated hippocampal levels of αCaMKII and CREB, but not ERK. Interestingly, enrichment caused a significant increase in hippocampal Ng levels both in Ng+/+ and Ng+/− mice that seemed to contribute to their improved LTP and behavioral performances. These results suggest that Ng gates the neuronal signaling reactions involved in learning and memory. During environmental enrichment, these Ng-regulated reactions are also critical for the enhancement of synaptic plasticity and cognitive functions.
Mobile manipulation: a challenge in integration

Mobile manipulation in many respects represents the next generation of robot applications. An important part of design of such systems is the integration of techniques for navigation, recognition, control, and planning to achieve a robust solution. To study this problem three different approaches to mobile manipulation have been designed and implemented. A prototypical application that requires navigation and manipulation has been chosen as a target for the systems. In this paper we present the basic design of the three systems and draw some general lessons on design and implementation.
Restoration of Tolerance in Lupus by Targeted Inhibitory Receptor Expression

Lupus, a multigenic autoimmune condition in which a breakdown of tolerance results in the development of autoantibodies, leads to a variety of pathologic outcomes. Despite the heterogeneity of factors influencing disease susceptibility, we demonstrate that the partial restoration of inhibitory Fc receptor (FcgRIIB) levels on B cells in lupus-prone mouse strains is sufficient to restore tolerance and prevent autoimmunity. FcgRIIB regulates a common B cell checkpoint in genetically diverse lupus-prone mouse strains, and modest changes in its expression can result in either tolerance or autoimmunity. Therefore, increasing FcγRIIB levels on B cells may be an effective way to treat autoimmune diseases.
New computing systems and future high-performance computing environment and their impact on structural analysis and design

Abstract Recent advances in computer technology that are likely to impact structural analysis and design are reviewed. A brief summary is given of the advances in microelectronics and networking technologies, and in the human-computer interaction paradigms and techniques. The major features of new and projected computing systems, including high-performance computers, parallel processing machines, and small systems are described. Advances in programming environment, numerical algorithms, and computational strategies for new computing systems are reviewed. The impact of the advances in computer technology on structural analysis and design is described. A scenario for future computing paradigm is presented and the near-term needs in the computational structures area are outlined.
On a multilinear character sum of Burgess

Abstract Let p be a sufficiently large prime and ( L i ) 1 ⩽ i ⩽ n a nondegenerate system of linear forms in n variables over F p . We establish a nontrivial estimate on the incomplete character sum ∑ x ∈ ∏ i = 1 n [ a i , a i + H ] X ( ∏ j = 1 n L j ( x ) ) , provided H > p 1 4 + e .
Chromosome mapping: Radiation hybrid data and stochastic spin models.

This work approaches human chromosome mapping by developing algorithms for ordering markers associated with radiation hybrid data. Motivated by the recent work of Boehnke, Lange, and Cox [Am. J. Hum. Genet. 49, 1174 (1991)], we formulate the ordering problem by developing stochastic spin models to search for minimum-break marker configurations. In one particular application, the methods developed are applied to 14 human chromosome-21 markers tested by Cox et al. [Science 250, 245 (1990)]. The methods generate configurations consistent with the best ones found by others. Additionally, we find that the set of low-lying configurations is described by a Markov-like ordering probability distribution. The distribution displays cluster correlations reflecting closely linked loci.
Additional work on the gravity separation of suspensions containing heavy and light particles

Cette etude theorique a pour objectif la determination des profils de concentration en fonction du temps. Les resultats obtenus sont compares a ceux obtenus par d'autres modeles faisant appel au concept de zone de suspension
A zone common to IgC globulins in the Fd region

The carboxy terminal portion of Fd of human IgG has been shown to be antigenically similar in all IgG globulins studied. An antibody was made in rabbits against a polypeptide from a myeloma globulin comprising this zone. This antibody was shown to give a reaction of identity with the four subclasses of IgG and other IgG myeloma globulins by precipitation after immunodiffusion. At the same time an antibody made in rabbits against a polypeptide comprising most of Fc as well as commercial anti-IgG showed these IgG globulins to be similarly related. No precipitation with either antibody occurred when several pure alpha and mu chains or either the kappa or the lambda light chains were used as antigens. There was no interaction between the antibody to the Fd and the antibody to the Fc polypeptides. A region in the carboxy half of Fd of IgG antigenically related, and paralleling the constant part of the light chains has therefore been demonstrated by serologic means. This additional constant zone in IgG had been postulated by other investigators.
The gas-phase reaction of naphthalene with N2O5 to form nitronaphthalenes

Abstract While the formation of nitroarenes from the reaction of NO 2 , containing traces of HNO 3 , in air with polycyclic aromatic hydrocarbons (PAH) adsorbed on combustion generated particles is now well recognized, little is known about the gas-phase reactions of PAH. In this study, the gas-phase reactions in air of N 2 O 3 with part-per-million levels of naphthalene have been studied at room temperature and atmospheric pressure in a 5800V Teflon-coated environmental chamber. The kinetic data obtained showed that in these N 2 O 5 -NO 3 -NO 2 -air mixtures studied, naphthalene did not react with the NO 3 radical at an observable rate, but that it reacted with N 2 O 5 with a rate constant of ~ (2–3) × 10 −17 cm 3 molecule −1 s −1 . Significant yields of 1-nitronaphthalene and 2-nitronaphthalene ( ~ 18 and ~ 7.5%, respectively) were obtained from this reaction. The latter is a procarcinogen capable of being metabolized in animals to the carcinogen β-naphthylamine. These results and their atmospheric implications are discussed.
Vascular Development during Distraction Osteogenesis Proceeds by Sequential Intramuscular Arteriogenesis Followed by Intraosteal Angiogenesis

Vascular formation is intimately associated with bone formation during distraction osteogenesis (DO). While prior studies on this association have focused on vascular formation locally within the regenerate, we hypothesized that this vascular formation, as well as the resulting osteogenesis, relies heavily on the response of the vascular network in surrounding muscular compartments. To test this hypothesis, the spatiotemporal sequence of vascular formation was assessed in both muscular and osseous compartments in a murine model of DO and was compared to the progression of osteogenesis. Micro-computed tomography (μCT) scans were performed sequentially, before and after demineralization, on specimens containing contrast-enhanced vascular casts. Image registration and subtraction procedures were developed to examine the co-related, spatiotemporal patterns of vascular and osseous tissue formation. Immunohistochemistry was used to assess the contributory roles of arteriogenesis (formation of large vessels) and angiogenesis (formation of small vessels) to overall vessel formation. Mean vessel thickness showed an increasing trend during the period of active distraction (p=0.068), whereas vessel volume showed maximal increases during the consolidation period (p=0.009). The volume of mineralized tissue in the regenerate increased over time (p<0.039), was correlated with vessel volume (r=0.59; p=0.025), and occurred primarily during consolidation. Immunohistological data suggested that: 1) the period of active distraction was characterized primarily by arteriogenesis in the surrounding muscle; 2) during consolidation, angiogenesis predominated in the intraosteal region; and 3) vessel formation proceeded from the surrounding muscle into the regenerate. These data show that formation of vascular tissue occurs in both muscular and osseous compartments during DO and that periods of intense osteogenesis are concurrent with those of angiogenesis. The results further suggest the presence of morphogenetic factors that coordinate the development of vascular tissues from the intramuscular compartment into the regions of osseous regeneration.
Statistical testing for paleocommunity recurrence: Are similar fossil assemblages ever the same?

Abstract Observations of the recurrence of similar fossil assemblages through long intervals of geologic time punctuated by rapid changes in both the composition and structure of fossil assemblages has recently resulted in the concept of “coordinated stasis” to describe this pattern in the behavior of paleocommunities through time. Coordinated stasis may imply the existence of ecological mechanisms that actively maintain particular community structures and thus have a significant impact on the process of macroevolution. However, before such mechanisms can be invoked, it must be shown that ecological stasis as observed in the fossil record is more significant than the persistence of similar community types due to the repeated reinvasion of recurring habitats from a persistent species pool (the “null hypothesis” for paleocommunity recurrence). Analysis of the relationship between communities and paleocommunities and an expansion of the ecological hierarchy at the community/paleocommunity level allows the creation of a rigorous definition of the entities composing the local paleocommunity (the samples collected within a stratigraphic horizon at a single locality), paleocommunity (groups of samples shown to be statistically identical), and paleocommunity type (groups of samples that are similar but can be shown to be statistically different). These definitions permit the development of the null model for paleocommunity recurrence and establish a base-level of variability within a local paleocommunity that permits rigorous statistical comparisons to be made between paleoecological samples at larger temporal and geographic scales. Paleoecological samples from four marine tongues in the Middle Pennsylvanian Breathitt Formation are used to analyze species abundance variability at several spatial and temporal scales and to test for paleocommunity recurrence. Although recurrence of statistically identical local paleocommunities occurs at single localities and between localities within individual marine units, it is usually not detectable between marine tongues, suggesting that paleocommunity recurrence in the marine strata of the Breathitt Formation is the recurrence of paleocommunity types and does not falsify the null hypothesis.
Occupational English as a Second Language.

The article presents an overview of OESL, its development, purposes, and characteristics, and guides the reader to potential sources of additional information. OESL training, which assists individuals in fulfilling their occupational goals, is a component of bilingual/bicultural education, an ‘umbrella’ term for language programs that help individuals develop bilingual skills and heighten their cultural awareness. Several operational OESL programs are cited as examples, including one by Ms. Garcelon and Ms. Alicia D. Ramirez: EST/AUTO MECHANICS SUPPLEMENTARY LESSONS. Portions of that program are produced to illustrate actual drills and exercises. In a subsequent section, persons within the OESL target population are broadly classified according to need, with an outline of strategies for meeting those needs. Characteristics of successful OESL programs are reviewed, with emphasis on open-entry/open-exit, individualized instruction, and a competency based, individualized approach. Preparation of OESL materials is illustrated and the competencies required of an effective OESL instructor are listed. The article emphasizes awareness, empathy, and imagination in designing and implementing programs to meet the diverse needs of OESL populations.