cssi/SciSciGPT-SciSciNet huggingface dataset:
History of Plant Ecology

Plant ecology originated during the late nineteenth century in Germany and Scandinavia. Early plant ecologists pursued two broad areas of research: synecology, the study of plant communities and autecology, the study of the adaptation of species to their environments. Plant ecology developed rapidly in Britain and the United States during the first decade of the twentieth century, before animal ecology and other specialties emerged. The study of plant communities, particularly plant succession, became the central focus of ecological research during the first half of the twentieth century. After Second World War, the status of plant ecology as a distinctive area of research declined as new fields such as population ecology and ecosystem ecology gained prominence. However, plant ecologists continued to make substantial contributions to these newer areas of research. Key Concepts: Early plant ecologists studied plant communities and the adaptation of species to the physical and biological environments. Laboratory physiology provided an important intellectual model for the early development of plant ecology. Plant ecology was the first ecological specialty to emerge, and plant ecologists were largely responsible for establishing the discipline of ecology. The process of plant succession was an important focus of research for American ecologists during the first half of the twentieth century. Population genetics and evolutionary theory of the Modern Synthesis strongly influenced the development of population ecology after Second World War. Population biology combined methods and ideas from population ecology, population genetics and evolutionary theory to study both plant and animal populations. Ecosystem ecology emphasised the important energy-capturing role of plants as the photosynthetic producers in terrestrial ecosystems. Long-term research carried out by large teams of scientists became a major feature of ecosystem ecology. Keywords: plant communities; population biology; population ecology; vegetation; plant geography; ecology; ecosystems; succession; adaptation; natural selection
Unified Verification Theory

We present an automata-theoretic framework to the verification of concurrent and nondeterministic programs. The basic idea is that to verify that a program P is correct one writes a program A that receives the computation of P as input and diverges only on incorrect computations of P. Now P is correct if and only if the program P A , which is obtained by combining P and A, terminates. This unifies previous works on verification of temporal properties and verification of fair termination.
First demonstration of GaAs on insulator (GOI) technology

Summary form only given. There is increased interest in the steam oxidation of AlAs, following the pioneering work done at University of Illinois. We report the first demonstration of GaAs On Insulator (GOI) technology using Al/sub 2/O/sub 3/ formed by the steam oxidation of AlAs as the buffer insulator. 500 /spl Aring/ of AlAs was grown on a GaAs buffer, followed by a 100 /spl Aring/ spacer (Al/sub 0.3/GaAs), 2000 /spl Aring/ channel (n-GaAs), 30 /spl Aring/ etch stop (Al/sub 0.7/GaAs) and the 200 /spl Aring/ n/sup +/ ohmic layer for contacts (InAs-GaAs superlattice). The three-terminal DC I-V characteristics of a GOI MESFET indicate that the device has negligible output conductance. The peak g/sub m/ is over 180 mS/mm at a drain current level of 320 mA/mm. The source and drain ohmic contact resistance is 0.2 /spl Omega/-mm and the knee voltage is about 1.2 volts. The f/sub T/ and f/sub max/ of this device are 9 GHz (which is close to the expected value for a 1.5 /spl mu/m gatelength device) and 44 GHz respectively. These results indicate that Al/sub 2/O/sub 3/ is a possible buffer layer insulator for III-V based FET technology and can form an enabling technology for a low substrate leakage, high output resistance GOI FETs, attractive for low power electronics.
Fetal frontal cortex transplanted to injured motor/sensory cortex of adult rats. II. VIP-, somatostatin-, and NPY-immunoreactive neurons

Fetal frontal cortex transplants that survived 2–9 months in cavities in adult rat motor/sensory cortex were processed for vasoactive intestinal polypeptide (VIP), somatostatin 14 (SS), and neuropeptide Y (NPY) immunocytochemistry, and NADPH-diaphorase (NADPH-d) histochemistry. All transplants had surviving VIP, SS, NPY, and NADPH-d neuronal perikarya and fibers with normal adult morphology. The number of peptidergic neurons within transplants, however, often appeared to be less than that in equivalent areas of host cortex. Most transplanted SS and VIP neuronal perikarya did not migrate to form the laminae characteristic of normal cortex. A few transplants had SS and VIP cells arranged in laminae in which the VIP processes were parallel to one another and perpendicular to one transplant surface, approximating normal host neocortex. VIP, NPY, and SS fibers crossed between host brains and transplants, suggesting that peptide host-transplant interactions are possible. All adult host cortical and most transplanted NPY neurons colocalized with NADPH-d. The failure of some transplanted NPY neurons to express NADPH-d suggests these transplanted cells may be functionally impaired, but that they can survive without the NADPH-d enzyme.
Inhibition of ATP release from Erythrocytes: A role for EPACs and PKC

Please cite this paper as: Adderley, Sridharan, Bowles, Stephenson, Sprague and Ellsworth (2011). Inhibition of ATP Release from Erythrocytes: A Role for EPACs and PKC. Microcirculation18(2), 128–135. Abstract Objective: Here we demonstrate that, in human erythrocytes, increases in cAMP that are not localized to a specific receptor-mediated signaling pathway for ATP release can activate effector proteins resulting in inhibition of ATP release. Specifically we sought to establish that exchange proteins activated by cAMP (EPACs) inhibit ATP release via activation of protein kinase C (PKC). Methods: ATP release stimulated by iloprost (ILO), or isoproterenol (ISO), was determined in the absence and presence of selective phosphodiesterase inhibitors and/or the EPAC activator, 8CPT2OMecAMP (8CPT). To determine whether EPACs inhibit ATP release via activation of PKC, erythrocytes were incubated with phorbol 12-myristate 13-acetate (PMA) prior to either forskolin or ILO in the absence and presence of a PKC inhibitor, calphostin C (CALC). Results: Selective inhibition of PDEs in one pathway inhibited ATP release in response to activation of the other cAMP-dependent pathway. 8CPT and PMA inhibited both ILO- and ISO-induced ATP release. Inhibition of ATP release with 8CPT was rescued by CALC. Conclusion: These results support the hypothesis that cAMP not localized to a specific signaling pathway can activate EPACs which inhibit ATP release via activation of PKC and suggest a novel role for EPACs in erythrocytes.
Systematics and Paleobiogeography of Late Triassic Gryphaea (Bivalvia) from the North American Cordillera

Evaluation of previously undescribed collections of Late Triassic Gryphaea from the North American Cordillera increases the temporal range and geographic distribution of the genus. Gryphaea (Gryphaea) arcuataeformis Kiparisova, G. cf. G. (Gryphaea) keilhaui Bohm, and a new species, G. (Gryphaea) nevadensis, occur in lower Carnian to upper Norian strata from Alaska, British Columbia, Oregon, and Nevada. The distribution is mostly primary with respect to the Upper Triassic North American Craton, and requires long-distance larval dispersal along the latitude of far-eastern Panthalassa. Unlike most modern oysters, the distribution of these Triassic gryphaeids may have been restricted to cool and deeper water environments.An early Carnian age of Gryphaea (Gryphaea) arcuataeformis places this species as the oldest known Gryphaea. When combined with late Carnian and Norian occurrences from the North and South American Cordillera, these data indicate that a low-latitude origin for the genus cannot be overlooked. Gryphaeids survived the end-Triassic extinction event presumably by living in refugia.
Ultrasonography of intrauterine devices

The intrauterine device (IUD) is gaining popularity as a reversible form of contraception. Ultrasonography serves as first-line imaging for the evaluation of IUD position in patients with pelvic pain, abnormal bleeding, or absent retrieval strings. This review highlights the imaging of both properly positioned and malpositioned IUDs. The problems associated with malpositioned IUDs include expulsion, displacement, embedment, and perforation. Management considerations depend on the severity of the malposition and the presence or absence of symptoms. Three-dimensional ultrasonography has proven to be more sensitive in the evaluation of more subtle findings of malposition, particularly side-arm embedment. Familiarity with the ultrasonographic features of properly positioned and malpositioned IUDs is essential.
Cell motility driven by actin polymerization

Certain kinds of cellular movements are apparently driven by actin polymerization. Examples include the lamellipodia of spreading and migrating embryonic cells, and the bacterium Listeria monocytogenes, that propels itself through its host's cytoplasm by constructing behind it a polymerized tail of cross-linked actin filaments. Peskin et al. (1993) formulated a model to explain how a polymerizing filament could rectify the Brownian motion of an object so as to produce unidirectional force (Peskin, C., G. Odell, and G. Oster. 1993. Cellular motions and thermal fluctuations: the Brownian ratchet. Biophys. J. 65:316–324). Their "Brownian ratchet" model assumed that the filament was stiff and that thermal fluctuations affected only the "load," i.e., the object being pushed. However, under many conditions of biological interest, the thermal fluctuations of the load are insufficient to produce the observed motions. Here we shall show that the thermal motions of the polymerizing filaments can produce a directed force. This "elastic Brownian ratchet" can explain quantitatively the propulsion of Listeria and the protrusive mechanics of lamellipodia. The model also explains how the polymerization process nucleates the orthogonal structure of the actin network in lamellipodia.
The effect of methyl linoleate hydroperoxide (MLHP), a possible toxic intermediate of ozone, on human normal and glucose‐6‐phosphate dehydrogenase (G‐6‐PD) deficient erythrocytes

Abstract Erythrocytes of both normal and G‐6‐PD deficient humans responded in a dose‐dependent manner to the oxidant stress of MLHP as measured by decreases in G‐6‐PD activity, increases in methemoglobin (METHB) levels and decreases in reduced glutathione (GSH). The G‐6‐PD deficient eryth‐rocytes displayed a markedly enhanced sensitivity to MLPH induced decreases in G‐6‐PD activity and METHB increases while being less sensitive than normal erythrocytes to changes in GSH levels.
Is obesity an emerging problem in Brazilian children and adolescents

A obesidade na infância e um problema emergente de saude publica em todo o mundo1. O alto indice de massa corporal (IMC, kg/m2) na infância esta associado a 1) hiperlipidemia, resistencia a insulina e hipertensao2; e 2) obesidade e doenca cardiovascular (DCV) na vida adulta3,4. Em muitos paises em desenvolvimento, baixo peso ao nascer, baixo peso e nanismo ainda sao prevalentes5,6, o que pode estar associado ao risco aumentado de DCV na vida adulta7. O duplo fardo representado por obesidade e baixo peso traz desafios economicos e de saude publica, especialmente nos paises que estao atravessando uma transicao socioeconomica. Neste numero do Jornal de Pediatria, Silva et al.10 comparam os padroes de crescimento de criancas e adolescentes brasileiros com as curvas de crescimento do Center for Disease Teste do suor Mastella G
Venture capitalists' decision policies across three countries: an institutional theory perspective

This paper examines the influence of economic institutions upon venture capitalists’ (VCs) decision policies. We conducted policy-capturing experiments on 119 VCs across three countries, representing distinct economic institutions (US, mature market economy; South Korea, emerging economy; and China, transitional economy). Results show that VCs in rules-based market economies (US) rely upon market information to a greater extent than VCs in emerging economies (Korea), and Chinese VCs (transitional economy) weight human capital factors more heavily than either US or Korean VCs. Findings suggest that, although professional institutions may dictate which information is included in VC decision policies, the extent to which that information is emphasized is determined partly by the economic institution in which the decision-maker operates. Journal of International Business Studies (2007) 38, 691–708. doi:10.1057/palgrave.jibs.8400291
Shock filter coupled to curvature diffusion for image denoising and sharpening

The frequent problem in low-level vision arises from the goal to eliminate noise and uninteresting details from an image, without blurring semantically important structures such as edges. Partial differential equations (PDEs) have recently dominated image processing research, as a very good tool for noise elimination, image enhancement and edge detection. In this paper, we present a biased PDE filter based on a coupling between shock filter and curvature diffusion. This model removes noise and sharpens edges efficiently. It preserves well the location of the shocks by synchronising both effects of smoothing and deblurring. Empirical results on different kinds of images confirm these advantages.
Subjective Workload Assessment in a Spatial Memory Task

Twelve subjects performed a spatial short-term memory task under several levels of difficulty and rated the workload associated with each using the Subjective Workload Assessment Technique (SWAT). SWAT ratings proved sensitive to two of the three difficulty manipulations in the memory task, and demonstrated greater sensitivity in this respect than either of two primary task measures that were employed. The results extend the applicability of SWAT to the type of spatial memory task used and, therefore, provide further support for the general applicability of SWAT as a workload measurement technique.
Distributed Data Acquisition for BNL802 II: Software

Multiple processes running on a VAX and on VME-based processors allow up to 16 detector sub-systems to run independently or coupled, with an aggregate throughput of 600 Kbytes/sec. VMS facilities are used extensively for command definition, message passing, controlling access to CAMAC and high voltage modules, and maintaining shared data structures.
French cinema, 1940–1944, and its socio-psychological significance: a preliminary probe

(1981). French cinema, 1940–1944, and its socio-psychological significance: a preliminary probe. Historical Journal of Film, Radio and Television: Vol. 1, No. 1, pp. 33-45.
Type I Error Rates for Parscale’s Fit Index

Type I error rates for PARSCALE’s fit statistic were examined. Data were generated to fit the partial credit or graded response model, with test lengths of 10 or 20 items. The ability distribution was simulated to be either normal or uniform. Type I error rates were inflated for the shorter test length and, for the graded-response model, also for the longer test length when the ability distribution was uniform. In conditions in which α was inflated, it was particularly high when one or more response categories were used infrequently. Overall, PARSCALE’s fit index is not recommended for short tests.
Enzyme mediated reduction of 21-Dehydrocorticosteroids at C-20: isolation and characterization of derivatives containing the 20β-Hydroxy-21-Aldehyde side chain

Abstract A method for the stereospecific reduction of 21-dehydrocorticosteroids with bacterial 20β-hydroxy-steroid dehydrogenase to form 20β-hydroxy-21-aldehyde derivatives is described. These products have been given the trivial designation “isocorticosteroids”. The isocorticosteroid homologues of 11-deoxy-corticosterone, corticosterone, 11-deoxycortisol and cortisol were prepared in yields of 84–96%. The new compounds have been characterized by physcial and chemical criteria.
Data-driven fuzzy sets for classification

Using the mass assignment mechanism, a fuzzy classifier can be derived directly from the class relative frequency distribution. Moreover, in this framework, a family of fuzzy sets can represent a class, thus adapting the classifier to the need of classification. Graduality and the corresponding concept of error can be used to guide the process of deriving class representing fuzzy sets. The classification algorithm is attractive due to its low complexity. Successful applications include imbalanced data classification problems where the class having fewer examples is the class of interest.
Surgical stem cell therapy for advanced heart failure patients.

Introduction Despite current treatment, heart failure is a contributing factor in just under 15 million deaths worldwide every year.1 Currently available options for heart failure patients consist of medical management, cardiac transplantation, device therapy, and now stem cell-based therapies. Although cardiac stem cell therapy has been performed in other countries, new surgically based trials with innovative advanced stem cell products are now being initiated in the United States.
Can early-type galaxies evolve from the fading of the disks of late-type galaxies?

We examine whether early-type galaxies in clusters may have evolved from later types by the fading of their disks (e.g., as a result of ram pressure stripping or strangulation) or by enhancement of the bulge luminosity (e.g., due to tidal interactions and mergers). For this purpose, we compare the bulge and disk luminosities of early- and late-type galaxies and of galaxies at different radial distances from the cluster center. We find that in order for early-type galaxies, including S0, to have evolved from late-type galaxies, their bulge luminosities must have been physically enhanced. Disk-fading models cannot explain the differences observed. We then show that galaxy bulges are systematically brighter at small projected distances from the cluster center, while disk luminosities are uncorrelated with clustercentric distance. Our results suggest that bulge enhancement, not disk fading, distinguishes early- from late-type galaxies and is thus at least partially responsible for the morphology-environment relation of bright cluster galaxies.
Hardware Acceleration for 3-D Radiation Dose Calculation

The problem of calculating accurate dose distributions lies in the heart of modern radiation therapy for cancer treatment. Software implementations of dose calculation algorithms are highly costly in terms of CPU time. This paper proposes a multi-engine hardware design for 3D dose calculation based on the collapsed-cone algorithm. The performance of the hardware with one engine (100 Mhz) is already superior to the software counterpart executed on a 2.4 GHz PC. By exploiting the inherent parallelism of the collapsed-cone algorithm, the proposed two-level design with multiple engines can achieve almost a linear speedup compared with the one-engine design. Due to its modular approach, the design can also be easily implemented on a multi-FPGA system for an even greater speedup.
The Effect of Pulse-Feeding a Protein Diet on Ovarian Maturation, Vitellogenin Levels, and Ecdysteroid Titre in Houseflies, Musca domestica, Maintained on Sucrose

Summary When Musca domestica females were maintained on sugar, most did not develop their ovarian follicles past stage 4. However, a 4 h pulse feeding of protein diet to these flies stimulated ovarian maturation and increased haemolymph ecdysteroid and vitellogenin levels. Ecdysteroid levels were significantly higher than in the the sugar-fed flies within 8 h of protein feeding, reaching a peak of 36 pg/ul at 28 h, and then decreased to starting levels by 52 h. The higher ecdysteroid concentrations were found in samples from houseflies that had stage 5 and 6 ovaries. Decreasing levels of ecdysteroid were associated with flies that had ovarian stages of 7 through 9. Diet influenced the concentration of specific ecdysteroids in the haemolymph. Pulse feeding protein increased the concentration of RIA-positive material that co-migrated on HPLC with ecdysone by 13 fold, but had no effect on the concentration of the material that co-migrated with 20-hydroxyecdysone. The concentrations of polar materials and RIA...
Do random (non-clonal) chromosome abnormalities in bone marrow predict a clone to come?

The biologic significance of clonal karyotypic abnormalities in human neoplasms is becoming better understood, but the significance of rare chromosomal aberrations is uncertain. Useful, yet arbitrary, cytogenetic definitions of a clone have been established and cases with a frequency of chromosome aberrations less than the accepted convention are explained by random loss, karyotypic instability/evolution, or other technical artifact. Are non-clonal chromosomal abnormalities that may predict future clinically significant clones being ignored? A brief case report is presented raising two such issues in the same myelodysplastic patient. This child had monosomy 7 and, later, trisomy 8, as well as increased numerical/structural aberrations seeming to predict relapse. Preliminary data from the Southwestern Oncology group is also presented. Non-clonal data should be included, when appropriate, in the clinical report.
Comparative Inhibitory Effect of Penicillin and Streptomycin Upon the Action of Staphylocoagulase.

SummaryComparative studies with penicillin and streptomycin on 18 strains of coagulase-positive staphylococci revealed that the action of staphylocoagulase on human plasma is inhibited to a greater extent by streptomycin than by penicillin.
Sediment retention in a bottomland hardwood wetland in Eastern Arkansas

One of the often-stated functions of wetlands is their ability to remove sediments and other particulates from water, thus improving water quality in the adjacent aquatic system. However, actual rates of suspended sediment removal have rarely been measured in freshwater wetland systems. To address this issue, suspended sediment dynamics were measured in a 85-km2 bottomland hardwood (BLH) wetland adjacent to the highly turbid Cache River in eastern Arkansas during the 1988–1990 water years. A suspended sediment mass balance was calculated using depth-integrated, flow-weighted daily measurements at wetland inflow and outflow points. Over the three-year period, suspended sediment load decreased an average of 14% between upstream and downstream sampling points. To test the idea that the suspended sediments were retained by the adjacent wetland and to determine what portion of the BLH forest was most responsible for retaining the suspended sediments, concurrent measurements of sediment accretion were made at 30 sites in the wetland using feldspar clay marker horizons, sedimentation disks, the137cesium method, and dendrogeomorphic techniques. Sedimentation rates exceeding 1 cm/yr were measured in frequently flooded areas dominated byNyssa aquatica andTaxodium distichum. Maximum sedimentation rates did not occur on the natural levee, as would be predicted by classical fluvial geomorphology, but in the “first bottom,” where retention time of the water reached a maximum. Multiple regression was used to relate sedimentation rates with several physical and biological factors. A combination of distance from the river, flood duration, and tree basal area accounted for nearly 90% of the variation in sedimentation rates.
Studies toward the synthesis of (−)-stenine

Herein is described an application of the acyl nitroso type 2 intramolecular Diels–Alder reaction as a key step in the progress toward the total synthesis of the Stemona alkaloid (−)-stenine. The chiral cycloaddition precursor is rapidly assembled from a cyclohexene intermediate synthesized through an asymmetric, organocatalyzed Robinson annulation. A key selective alkene reduction provides a tricyclic intermediate which could prove useful in the synthesis of the titular natural product.
FINITE-TIME STABILIZATION OF NONSMOOTHLY STABILIZABLE SYSTEMS

Abstract The problem of global finite-time stabilization is investigated in this paper. Using the finite-time Lyapunov stability theorem and the nonsmooth feedback design method developed recently, with a suitable twist, we prove that it is possible to achieve global finite-time stabilizability for a significant class of nonlinear systems which has been known not to be smoothly stabilizable, even locally, but can be globally asymptotically stabilized by Holder continuous state feedback.
On the variation of SO2 emission from volcanoes

Introduction these only since 1979 and 1980 respectively. However, as part of an on-going research proIn 1973, Stoiber and Jepsen used remote sengram, the SOz flux from several volcanoes in sing techniques to measure the S02 flux from Nicaragua, Guatemala, and Sicily have been several volcanoes in Central America. Using measured on a fairly regular basis. The object these data, they estimated that the global conof this paper will be to examine the results from tribution of SO2 from volcanoes was on the order some of those volcanoes and interpret how they of 7 × 10 G metric tons per year. This initial estimight effect flux estimate and prediction mate neglected sulfur in any form other than techniques. gaseous SO2 and did not include the contribution from erupting volcanoes. This number was Instrumentation and techniques subsequently modified by Stoiber et al. (1983b) and Stoiber et al. (1987, this volume ) to around The instrument used to remotely measure the 1.87× 107 tons per year and includes sulfate SOz flux is a correlation spectrometer (COSaerosols, and emission from erupting volcanoes. PEC) developed by Barringer Resarch in Another important application of remote Toronto, Canada, primarily for environmental sensing of S02 from volcanoes is forecasting of monitoring of SOz. The theory of the COSPEC eruptions. This has proven feasible at Mt. Etna operation has been well documented and inter(Malinconico, 1979) and Mount St. Helens ested readers are referred to the following (Casadevall et al., 1981). papers: Newcomb and Millan (1970), Moffat For both of these applications, it is important and Millan (1971), Millan et al. (1976), Millan to understand the longand short-term pat(1978, 1980) and Millan and Hoff (1978). terns of SO2 emission from volcanoes. ContinThe COSPEC provides straightforward uous monitoring of all volcanoes is at best techniques for remotely monitoring the SOz flux impractical. Only Kilauea and Mount St. from volcanoes. The instrument is compact, Helens have nearly continuous records and durable, and can be used in a variety of modes.
Correlated Motions and Interactions at the Onset of the DNA-Induced Partial Unfolding of Ets-1

The binding of the Ets-1 transcription factor to its target DNA sequence is characterized by a highly unusual conformational change consisting of the unfolding of inhibitory helix 1 (HI-1). To probe the interactions that lead to this unfolding, we performed molecular dynamics simulations of the folded states of apo-Ets-1 and the Ets-1-DNA complex. The simulations showed large differences in correlated motions between helix 4 (H4) and HI-1. In apo-Ets-1, H4 and HI-1 moved in-phase and stabilized each other by hydrogen bonding and macrodipolar interactions, whereas in the DNA-bound state, the motion was out-of-phase, with a disruption of the stabilizing interactions. This change in motion was due to hydrogen-bonding interactions between helix 1 (H1) and the DNA. The dipolar energy between H1 and H4 was modulated by hydrogen bonds between H1 and DNA, and, in accordance with experiments, elimination of the hydrogen bonds increased the stability of HI-1. The simulations confirm that the hydrogen bonds between H1 and DNA act as a conformational switch and show that the presence of DNA is communicated from H1 to H4, destabilizing HI-1. The calculations reveal a critical role for correlated motions at the onset of the DNA-induced unfolding.
Effectiveness of a home based early intervention program with infants of adolescent mothers

The results of this study suggests that a home based early intervention program can be effective with infants doubly at risk: biomedically as offspring of adolescent mothers and environmentally from low SES. At 30 months of age only 11% of the 19 children in the early intervention group remained at risk while 50% of the 18 children in the control group remained at risk.
Evidence for an ATP-dependent bile acid transport protein other than the canalicular liver ecto-ATPase in rats

Abstract BACKGROUND & AIMS: Canalicular secretion is rate limiting in overall blood-to-bile transport of bile acids. Studies using transfected cells have implicated the canalicular ecto-adenosine triphosphatase (ecto- ATPase) in adenosine triphosphate (ATP)-dependent bile acid transport. However, the structural features of this ecto-ATPase are not those anticipated for an in-to-out ATP-dependent transporter. The aim of this study was to explore the possible existence of an ATP-dependent bile acid transport mechanism distinct from ecto-ATPase. METHODS: Bile acid transport activity and ecto-ATPase expression were analyzed in primary rat hepatocytes, rat hepatoma HTC cells, and specially adapted HTC (HTC- R) cells using plasma membrane vesicles and Northern blot, slot blot, ribonuclease protection assay, and Western blot analyses. RESULTS: Plasma membranes isolated from HTC-R cells exhibited ATP-dependent taurocholate transport, which was many-fold greater than that in HTC cells. Hepatocytes showed the highest transport rates. Protein and RNA analyses showed very low expression of ecto-ATPase in HTC and HTC-R cells compared with hepatocytes. There was no difference between the two cell types at both the RNA and protein level. CONCLUSIONS: These findings show the presence in HTC-R cells and, apparently in hepatocytes, of one or more proteins other than the ecto-ATPase that mediate ATP-dependent transport of bile acids. (Gastroenterology 1997 Jul;113(1):249-54)
Effect of somatostatin analog on postprandial satiation in obesity.

Objective: Altered satiation may impact postprandial symptoms and potentially change food intake in obesity. Our aim was to compare effects of octreotide and placebo on postprandial symptoms, satiation, and gastric volumes in obesity. Research Methods and Procedures: In a randomized, parallel-group, double-blind, placebo-controlled study, 26 obese but otherwise healthy participants received 100 μg of octreotide or placebo subcutaneously 30 minutes before each study. Studies were performed on 2 separate days and included validated non-invasive techniques: 99mTc-single photon emission computed tomography imaging to measure fasting stomach volume and gastric volume changes after 90 mL of water and 240 mL of Ensure and a standardized nutrient drink test to measure the maximum tolerated volume and postprandial symptoms. Results: Relative to placebo, octreotide increased gastric volume after 90 mL of water; however, fasting and gastric volume change post-Ensure and maximum tolerated volume of Ensure were not different. Octreotide decreased sensations of fullness (p = 0.035) and bloating (p = 0.05) and tended to reduce aggregate symptoms (p = 0.07) after the fully satiating meal. Discussion: In obese individuals, somatostatin analog significantly reduced postprandial sensations after a satiating meal without altering maximum tolerated meal volume or postnutrient gastric volume, suggesting an effect on upper gut sensation. The role of somatostatin as a permissive factor in the development of obesity by reducing postprandial sensations deserves further study.
Evidence for periodic breakup of a radially modulated 0.35 μm laser beam due to thermal self-focusing in a plasma

Abstract Azimuthal periodic breakup of a radially modulated 0.35 μm laser beam has been inferred in plasmas produced from solid targets. The breakup is more severe in gold plasmas compared to glass or aluminum plasmas and occurs at rather modest laser intensities of ∼5x10 12 W/cm 2 . Thermal filamentation is suggested as the mechanism for the observed beam breakup.
A New Species of Apateodus (Teleostei: Aulopiformes) from the Upper Cretaceous Niobrara Chalk of Western Kansas, U.S.A.

ABSTRACT Apateodus Woodward (Teleostei: Aulopiformes) is a Late Cretaceous bony fish that is known by only a few cranial specimens. On the basis of a previously unreported partial skeleton of Apateodus from the Smoky Hill Chalk Member (lower Campanian portion) of the Niobrara Chalk in western Kansas, U.S.A., here, we emend the diagnosis for the genus and describe a new species, A. busseni. The specimen substantiates the presence of Apateodus in the North American Western Interior Seaway during the early Campanian and marks the fifty-fifth osteichthyan fish so far recognized from the Niobrara Chalk of Kansas. Like another species of Apateodus, A. striatus (Agassiz), Apateodus busseni sp. nov. was a medium-sized (ca. 40 cm TL), slender pelagic fish, that was likely capable of fast swimming.
High resolution mapping of mast cell membranes reveals primary and secondary domains of Fc(epsilon)RI and LAT.

In mast cells, cross-linking the high-affinity IgE receptor (FceRI) initiates the Lyn-mediated phosphorylation of receptor ITAMs, forming phospho-ITAM binding sites for Syk. Previous immunogold labeling of membrane sheets showed that resting FceRI colocalize loosely with Lyn, whereas cross-linked FceRI redistribute into specialized domains (osmiophilic patches) that exclude Lyn, accumulate Syk, and are often bordered by coated pits. Here, the distribution of FceRI β is mapped relative to linker for activation of T cells (LAT), Grb2-binding protein 2 (Gab2), two PLCγ isoforms, and the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase), all implicated in the remodeling of membrane inositol phospholipids. Before activation, PLCγ1 and Gab2 are not strongly membrane associated, LAT occurs in small membrane clusters separate from receptor, and PLCγ2, that coprecipitates with LAT, occurs in clusters and along cytoskeletal cables. After activation, PLCγ2, Gab2, and a portion of p85 colocalize with FceRI β in osmiophilic patches. LAT clusters enlarge within 30 s of receptor activation, forming elongated complexes that can intersect osmiophilic patches without mixing. PLCγ1 and another portion of p85 associate preferentially with activated LAT. Supporting multiple distributions of PI3-kinase, FceRI cross-linking increases PI3-kinase activity in anti-LAT, anti-FceRIβ, and anti-Gab2 immune complexes. We propose that activated mast cells propagate signals from primary domains organized around FceRIβ and from secondary domains, including one organized around LAT.
Reliability of Ku-Band GaAs Power FETs Under Highly Stressed RF Operation

Accelerated life tests under rf drive have been performed on power FETs with sub-micron aluminum gates and plated via-hole source connections designed for operation up to Ku-band. The tests were performed on a nine channel X-band test station under typical operating bias of Vds = 10 V. The rf level was set to drive the devices well into gain compression with I mA net DC gate current. Two failure modes were observed depending on channel temperature. At 228°C a gradual reduction in gain was observed, accompanied by a slow drop in Ids. MTTF according to a failure criterion of 1 dB gain degradation was 2,100 hours. No gate degradation was observed even after 3,300 hours on test. The only observable effects were drain migration and a slightly reduced Idss. At 280°C the failure mode was catastrophic with an MTTF of 120 hours indicating that such high temperatures do not realistically accelerate the normal operating failure mode. Preliminary results are presented for a third long-term test at 218°C.
Dynamic constrints associated with the formation of SiS(a 3Σ+) from the Si—OCS chemiluminescent reaction

Abstract The Si—OCS reaction is characterized by chemiluminescent emission from the excited electronic a 3 Σ + and b 3 ↶ states of SiS. The vibrational population distribution of the a 3 Σ + state is found to be virtually Boltzmann at 645 K. In contrast, the vibrational distribution for the b 3 ↶ state appears to be far from Boltzmann. A surprisal analysis indicates that a dynamic constraint affects the population of vibrational quantum levels in the a 3 Σ + state. This constraint appears to be the inability of the Si—OCS reaction to convert the internal energies of the silicon atoms and OCS molecules and the relative translational energy of these reactants into product SiS internal excitation.
Effects of Thermal Loading on Fiber-Reinforced Composites With Constituents of Differing Thermal Expansivities

Estimates of the magnitudes of elastic stresses and elastoplastic stresses and strains were made for tungsten fiber-reinforced 80Ni + 20Cr matrix composites. Heating or cooling between 80 and 2000 F was assumed. The calculated elastic stresses exceeded representative or estimated strengths of constituents. For composites with less than 0.65 volume fraction of fiber, plastic flow was considered possible, and elastoplastic solutions indicated that stresses would be reduced but with the concomitant occurrence of sufficiently large strain ranges, particularly in the matrix, to pose a possible thermal fatigue problem. Limited experimental studies on tungsten fiber-copper matrix composites heated and cooled a number of times between 80 and 1600 F in a conventional furnace and then heated from 80 to 1652 F in a hot-stage microscope resulted in matrix microfracture for a 70 volume fraction fiber composite and substantial matrix strain for a 40 volue fraction fiber composite.
Gamma-tubulin and 53BP1 as candidate biomarkers of human papillomavirus-associated anal dysplasia.

Background HIV+ men who have sex with men (MSM) are at increased risk of developing anal squamous cell carcinoma. High-grade anal intraepithelial neoplasia (HG-AIN or AIN2/3) is the consequence of persistent infection with high-risk human papillomaviruses and is a precursor to cancer. No biomarkers exist to identify patients with HGAIN at risk of malignant progression. We investigated two candidate biomarkers of genomic instability, gamma-tubulin and 53BP1, in a series of anal biopsies from HIV+ MSM by immunofluorescence microscopy. Gamma-tubulin staining is used to assess centrosome abnormalities as a potential source of cell division errors and aneuploidy, while staining for 53BP1 nuclear foci reflects the presence of DNA double strand breaks. Materials and methods Anal biopsies were obtained from HIV+ MSM undergoing high-resolution anoscopy and reported using the Bethesda 2001 classification system as AIN1 through 3 or carcinoma. Normal colonic tissue served as controls. The percentage of cells with abnormal centrosome number (more than two per cell) and DNA damageassociated 53BP1 foci was assessed and correlated with the histopathological diagnosis. Eighty-eight biopsies were stained for gamma-tubulin, and ninety biopsies were stained for 53BP1. Results The mean percentage of cells with abnormal centrosomes was 1.5% in AIN1, 1.3% in AIN2, and 0.9% in AIN3. No controls showed centrosome aberrations. A single biopsy diagnosed as carcinoma contained 16.1% cells with abnormal centrosomes. The mean percentage of cells with abnormal 53BP1 foci was 2.5% in controls, 17% in AIN1, 18.5% in AIN2, and 5.2% in AIN3. Higher levels of abnormal 53BP1 foci were seen in AIN1 and AIN2 compared to controls based on pair-wise comparisons between control and AIN1 (p=0.0008) and control and AIN2 (p=0.0030) using the Mann Whitney test. Lower levels of 53BP1 foci were seen in AIN3 compared to AIN1 and 2 based on pair-wise comparisons between AIN1 versus AIN3 (p=0.0034) and between AIN2 versus AIN3 (p=0.0056). Conclusion
Sorption of non-ionic aliphatic molecules from aqueous solutions on clay minerals clay-organic studies—VII☆

Abstract Aqueous solutions of some non-ionic, aliphatic compounds are mixed with aqueous suspensions of kaolinite, gibbsite and montmorillonite. From the concentrations of the resulting organic solutions, the apparent sorptions of the organic molecules on the clay surfaces are determined. The results are expressed in m moles/m 2 of surface, molecules sorbed per 100 A 2 , and as an equivalent number of packed organic layers. Gibbsite appears to sorb more organic material than does kaolinite, and kaolinite than montmorillonite. Tentative explanations are suggested. The steps involved in the sorption calculations are examined critically, and especially the consequences arising from the sorption of both water and organic molecules on the clay surfaces.
Inorganic composition of fine particles in mixed mineral dust-pollution plumes observed from airborne measurements during ACE-Asia

[1] Chemical characteristics of inorganic water-soluble aerosol particles measured in large Asian springtime dust events during the Asian Pacific Regional Characterization Experiment (ACE-Asia) were investigated. Three specific flights (flights 6, 7, and 10) in the Yellow Sea boundary layer with high mineral dust concentrations mixed with pollutants from Asian urban centers are presented. Measurements during a similar campaign, Transport and Chemical Evolution over the Pacific (TRACE-P), in the same region suggested that fine-particle ammonium sulfate and nitrate salts, and potassium, apparently from biomass burning, are common particle ionic constituents in polluted air. Observations from the ACE campaign show similar characteristics and found that the main component of water-soluble mineral dust was Mg2+ and Ca2+. Ion charge balances of measured fine and total aerosol suggest that a significant fraction of the Mg2+ and Ca2+ observed were in the form of carbonates. In polluted air mixed with dust that advected directly from large urban regions in roughly half a day to 1 day (flights 6 and 7), much of the fine-particle nitrate and sulfate (approximately 80%) was apparently associated with ammonium or potassium, the rest likely associated with mineral dust. Only air masses that spent 2–5 days over the Yellow Sea (flight 10) had clear evidence of Cl− depletion. Initial mass accommodation coefficients much less than 0.1 for uptake of SO2 or HNO3 by mineral dust in urban plumes containing fossil fuel and biomass-burning emissions could explain the observations. The data suggest an accommodation coefficient dependence on relative humidity.
PS2-37: Design Considerations and Population Identification for Implementing a Dental Virtual Data Warehouse: Feasibility, Table Structure and Data Elements

Background/Aims The population seeking dental care at the Marshfield Clinic has grown substantially in recent years, partly as a result of increased capacity with the construction of new Marshfield Clinic dental clinics. The influx of additional dental data presents a great opportunity to enhance our dental research within the Marshfield Clinic Research Foundation and facilitate external collaborations. In order to collaborate in multi-site dental research studies, creation of a standardized data structure (analogous to the HMORN Virtual Data Warehouse) will be an enormous asset.
On-The-Job Training for Cataloging and Classification

Training for cataloging and classification within the Cataloging Department is discussed for two levels of staff, copy catalogers and original catalogers. A general pattern which moves from learning to catalog straightforward materials which require minimal editing to processing materials which are progressively more complex is described for copy catalogers. A survey of heads of cataloging departments reveals that there is a general feeling that cataloging and classification are being shortchanged in library school training and recommendations for such training are made. Training programs for original catalogers also follow a pattern, from working with LC copy to preparing original cataloging records. Some variations to the training patterns for each group are noted. The article concludes with a discussion of continuing education for both groups.
DC-SIGN and DC-SIGNR: helping hands for HIV.

Abstract The ability of dendritic cells (DCs) to promote HIV infection of T cells efficiently has been linked to the C-type lectin DC-specific intercellular adhesion molecule (ICAM)-grabbing nonintegrin (DC-SIGN). DC-SIGN and its homolog DC-SIGN-related (DC-SIGNR) capture and transmit human and simian immunodeficiency viruses to a wide variety of receptor-positive cells. The expression patterns of DC-SIGN and DC-SIGNR suggest that they might play roles in both horizontal and vertical transmission, as well as dissemination of virus within the host. In vivo experiments are required to prove these hypotheses and might pave the way for the development of new inhibitors of viral entry.
Efficiencies of MLE and BLUE for parameters of an accelerated life-test model

Maximum-likelihood estimates (MLE) and best-linear-unbiased estimates (BLUE) of parameters of an accelerated life-test model were compared according to the mean-square error criterion in small and moderate sample size cases. A factorial experiment was used to investigate the effects of the: (1) number of levels of the acceleration variable, (2) percent censorship, and (3) sample size. Overall, the two kinds of estimators were of comparable efficiencies. However, where there were two or less uncensored observations, at any level(s) of the acceleration variable, the MLE was clearly favored. This is in accord with findings for single sample cases, where MLE and BLUE for location and scale parameters of the Weibull and the extreme-value distributions were compared. >
Antenatal Diagnosis of the Haemoglobinopathies

Summary. The β-chain of adult haemoglobin is expressed in fetal red cells during the first to mid-trimester of human pregnancy. The rate of β-chain production is approximately 8% of γ-chain production during this period of gestation. The production of βs-chains is readily detectable and the reduction of βA-chain production in thalassaemia may also be observed. Acquisition of fetal cells by means of placentocentesis or placental venipuncture via a fetoscope are current sampling methods which have been shown to be useful. Thus far five attempts at such antenatal diagnosis have been made, four for β-thalassaemia and one for sickle cell anaemia. In three of these attempts (all for β-thalassaemia), a sample of fetal blood was obtained. In one, the correct diagnosis of a normal fetus was made. In a second fetus, the diagnosis of β-thalassaemia trait was made; the infant was normal. In a third, the diagnosis of a normal fetus was made; the infant had β-thalassaemia trait. These early results indicate that attempts at antenatal diagnosis of the common β-chain abnormalities do not necessarily disturb pregnancy and can yield important information which encourages mothers at risk to retain pregnancies.
Ends and beginnings in the mathematical modelling of chemical engineering systems

Abstract The mathematical model is considered as an imitator of a natural phenomenon or an artifactual construction. Its structure and expression are discussed with special reference to the establishment of boundary conditions and the importance of rendering the variables and parameters dimensionless. This is illustrated by the simpler models of chemical reactors and the mutual relationship of these is considered.