cssi/SciSciGPT-SciSciNet huggingface dataset:
Do upwelling filaments result in predictable biological distributions in coastal upwelling ecosystems

Abstract We used satellite sea surface temperature (SST) images and in situ zooplankton data collected in four summers of field sampling in the northern California Current to address the question: Can the physical variables that indicate advective mesoscale circulation features (e.g. upwelling filaments) be used to infer biological distributions? Transects were selected from research cruises conducted when upwelling filaments were present in our study region and compared to transects occupied when filaments were not present. The hydrography and distribution of several indicator species of copepods were examined along each transect. SST in filaments ranged from 1.5 °C to 3.0 °C lower than the surrounding ocean water. Distributions of coastal and oceanic taxa reflected the SST patterns. Coastal taxa occurred offshore in higher abundances in cold upwelling filaments than in the surrounding warm ocean water. In contrast, species with oceanic and sub-tropical affinities were most abundant where warm surface water was present. Biomass and species abundances varied substantially among cruises and locations and so could not be quantitatively predicted by SST patterns. However, upwelling filaments consistently expanded the across-shelf region in which high zooplankton biomass occurred, ‘spreading’ the biomass from the continental shelf into offshore regions of the upwelling system. We conclude with a discussion of the sampling strategies necessary to capture ecosystem variability caused by these dynamic circulation features.
Deep cavitands provide organized solvation of reactions

Deep self-folding cavitands have been shown to stabilize the charged enolate intermediate of the alpha-deuteration of activated olefins by means of a network of organized solvation.
Effects of the steroid antagonist RU486 on dimerization of the human progesterone receptor.

We previously reported, using a coimmunoprecipitation assay, that the B form (PR-B) of the human progesterone receptor from T47D human breast cancer cells dimerizes in solution with the A receptor (PR-A) and that the extent of dimerization correlates with receptor binding activity for specific DNA sequences [DeMarzo, A.M., Beck, C.A., Onate, S.A., & Edwards, D.P. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 72-76]. This suggested that solution dimerization is an intermediate step in the receptor activation process. The present study has tested the effects of the progesterone antagonist RU486 on solution dimerization of progesterone receptors (PR). As determined by the coimmunoprecipitation assay, RU486 binding did not impair dimerization of receptors; rather, the antagonist promoted more efficient solution dimerization than the progestin agonist R5020. This enhanced receptor dimerization correlated with a higher DNA binding activity for transformed receptors bound with RU486. RU486 has been shown previously to produce two other alterations in the human PR when compared with R5020. PR-RU486 complexes in solution exhibit a faster sedimentation rate (6 S) on salt-containing sucrose density gradients than PR-R5020 complexes (4 S), and PR-DNA complexes have a faster electrophoretic mobility on gel-shift assays in the presence of RU486. We presently show that the 6 S PR-RU486 complex is a receptor monomer, not a dimer. The increased sedimentation rate and increased mobility on gel-shift assays promoted by RU486 were also observed with recombinant PR-A and PR-B separately expressed in insect cells from baculovirus vectors. These results suggest that RU486 induces a distinct conformational change both in PR monomers in solution and in dimers bound to DNA. We also examined whether conformational changes in PR induced by RU486 would prevent a PR polypeptide bound to RU486 from heterodimerization with another PR polypeptide bound to R5020. To evaluate this, PR-A and PR-B that were separately bound to R5020 or RU486 in whole cells were mixed in vitro. PR-A-RU486 was capable of dimerization with PR-B-R5020, and this was demonstrated for heterodimers both formed in solution and bound to specific DNA. The capability to form heterodimers in vitro raises the possibility that the antagonist action of RU486 in vivo could in part be imposed in a dominant negative fashion through heterodimerization between one receptor subunit bound to an agonist and another bound to RU486.
Specific Subunits of Heterotrimeric G-Proteins Play Important Roles during Nodulation in Soybean

Heterotrimeric G proteins comprising Gα, Gβ, and Gγ subunits regulate many fundamental growth and development processes in all eukaryotes. Plants possess a relatively limited number of G-protein components compared with mammalian systems, and their detailed functional characterization has been performed mostly in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa). However, the presence of single Gα and Gβ proteins in both these species has significantly undermined the complexity and specificity of response regulation in plant G-protein signaling. There is ample pharmacological evidence for the role of G proteins in regulation of legume-specific processes such as nodulation, but the lack of genetic data from a leguminous species has restricted its direct assessment. Our recent identification and characterization of an elaborate G-protein family in soybean (Glycine max) and the availability of appropriate molecular-genetic resources have allowed us to directly evaluate the role of G-protein subunits during nodulation. We demonstrate that all G-protein genes are expressed in nodules and exhibit significant changes in their expression in response to Bradyrhizobium japonicum infection and in representative supernodulating and nonnodulating soybean mutants. RNA interference suppression and overexpression of specific G-protein components results in lower and higher nodule numbers, respectively, validating their roles as positive regulators of nodule formation. Our data further show preferential usage of distinct G-protein subunits in the presence of an additional signal during nodulation. Interestingly, the Gα proteins directly interact with the soybean nodulation factor receptors NFR1α and NFR1β, suggesting that the plant G proteins may couple with receptors other than the canonical heptahelical receptors common in metazoans to modulate signaling.
Delivery of antisense oligodeoxyribonucleotides against the human epidermal growth factor receptor into cultured KB cells with liposomes conjugated to folate via polyethylene glycol.

Abstract Antisense oligodeoxyribonucleotides targeted to the epidermal growth factor (EGF) receptor were encapsulated into liposomes linked to folate via a polyethylene glycol spacer (folate-PEG-liposomes) and efficiently delivered into cultured KB cells via folate receptor-mediated endocytosis. The oligonucleotides were a phosphodiester 15-mer antisense to the EGF receptor (EGFR) gene stop codon (AEGFR2), the same sequence with three phosphorothioate linkages at each terminus (AEGFR2S), a randomized 15-mer control of similar base composition to AEGFR2 (RC15), a 14-mer control derived from a symmetrized Escherichia coli lac operator (LACM), and the 5'-fluorescein-labeled homologs of several of the above. Cellular uptake of AEGFR2 encapsulated in folate-PEG-liposomes was nine times higher than AEGFR2 encapsulated in nontargeted liposomes and 16 times higher than unencapsulated AEGFR2. Treatment of KB cells with AEGFR2 in folate-PEG-liposomes resulted in growth inhibition and significant morphological changes. Curiously, AEGFR2 and AEGFR2S encapsulated in folate-PEG-liposomes exhibited virtually identical growth inhibitory effects, reducing KB cell proliferation by > 90% 48 hr after the cells were treated for 4 hr with 3 microM oligonucleotide. Free AEGFR2 caused almost no growth inhibition, whereas free AEGFR2S was only one-fifth as potent as the folate-PEG-liposome-encapsulated oligonucleotide. Growth inhibition of the oligonucleotide-treated cells was probably due to reduced EGFR expression because indirect immunofluorescence staining of the cells with a monoclonal antibody against the EGFR showed an almost quantitative reduction of the EGFR in cells treated with folate-PEG-liposome-entrapped AEGFR2. These results suggest that antisense oligonucleotide encapsulation in folate-PEG-liposomes promise efficient and tumor-specific delivery and that phosphorothioate oligonucleotides appear to offer no major advantage over native phosphodiester DNA when delivered by this route.
Effects of surface grinding conditions on the reciprocating friction and wear behavior of silicon nitride

The relationship between two significantly different surface grinding conditions and the reciprocating ball-on-flat friction and wear behavior of a high-quality, structural silicon nitride material (GS-44) was investigated. The slider materials were silicon nitride NBD 200 and 440C stainless steel. Two machining conditions were selected based on extensive machining and flexural strength test data obtained under the auspices of an international, interlaboratory grinding study. The condition categorized as {open_quotes}low strength{close_quote} grinding used a coarse 80 grit wheel and produced low flexure strength due to machining-induced flaws in the surface. The other condition, regarded as {open_quotes}high strength grinding,{close_quotes} utilized a 320 grit wheel and produced a flexural strength nearly 70% greater. Grinding wheel surface speeds were 35 and 47 m/s. Reciprocating sliding tests were conducted following the procedure described in a newly-published ASTM standard (G- 133) for linearly-reciprocating wear. Tests were performed in directions both parallel and perpendicular to the grinding marks (lay) using a 25 N load, 5 Hz reciprocating frequency, 10 mm stroke length, and 100 m of sliding at room temperature. The effects of sliding direction relative to the lay were more pronounced for stainless steel than for silicon nitride sliders. The wear of stainless steel was less thanmore » the wear of the silicon nitride slider materials because of the formation of transfer particles which covered the sharp edges of the silicon nitride grinding grooves and reduced abrasive contact. The wear of the GS-44 material was much greater for the silicon nitride sliders than for the stainless steel sliders. The causes for the effects of surface-grinding severity and sliding direction on friction and wear of GS-44 and its counterface materials are explained.« less
Interpreting spatial economic structure: Feedback loops in the Indonesian interregional economy, 1980, 1985

Abstract In this paper, an alternative methodology is proposed to try to uncover the nature of the interregional economic structure that has tended to reinforce the hegemonic role that Java and Sumatera play in the Indonesian economy. The interpretation is made through the application of feedback loop analysis to a set of interregional input-output tables for 1980 and 1985. Feedback loop analysis offers an alternative perspective that is situated between the often too aggregated linkages view derived from usual applications of input-output analysis and the very disaggregated approach of structural path analysis in which the myriad paths of interaction present a daunting problem of classification and interpretation. The Indonesian economy is divided into five regions (Sumatera, Java, Kalimantan, Sulawesi and the Eastern Islands) and three sectors (primary activities, manufacturing and services). Even over a period of five years, important changes in the circulation of flows were observed; in particular, intraregional flows grew more rapidly that interregional flows especially in Java and Sumatera, while there were some changes in the circulation patterns of the interregional flows.
Detecting emerging topics and trends via predictive analysis of ‘meme’ dynamics

Discovering and characterizing emerging topics and trends through analysis of Web data is of great interest to security analysts and policy makers. This paper considers the problem of monitoring social media to spot emerging memes - distinctive phrases which act as “tracers” for discrete cultural units - as a means of rapidly detecting new topics and trends. We have recently developed a method for predicting which memes will propagate widely and which will not, thereby enabling the discovery of significant topics. Here we demonstrate the efficacy of this approach through case studies involving political memes and memes associated with an emerging cyber threat.
Measurement of the volume of an extended source seen by a spectrometer.

Number density of atomic constituents present in plasma extended source determined by spectroscopic volume measurement
Recent developments in the numerical solution of differential/algebraic systems

Abstract In this paper we survey some recent developments in the numerical solution of nonlinear differential/algebraic equation (DAE) systems of the form 0 = F ( t , y , y '), where ∂F ∂y' may be singular. Initial value problems in DAEs arise in a wide variety of applications, including circuit and control theory, chemical kinetics, modeling of constrained mechanical systems, fluid dynamics and robotics. DAE systems include standard form ODEs as a special case, but they also include problems which are in many ways quite different from ODEs. We explore some classes of initial value problems which can be solved by backward differentiation formulas, and discuss some results on the order of convergence of implicit Runge-Kutta methods applied to DAE systems. Finding a consistent set of initial conditions is often a problem for DAE systems arising in applications. We outline some recent work on a general algorithm for finding consistent initial conditions. Finally, we discuss some new developments in the numerical solution of DAE boundary value problems.
Aqueductal Lesions in 6-aminonicotinamide-treated Suckling Mice

Suckling mice which received a single intraperitoneal injection of 6-aminonicotinamide on the 5th postnatal day, consistently developed hydrocephalus. During the early stages of hydrocephalus (7–9 days after injection), aqueductal lesions were characterized by edematous ependymal and subependymal cells, and spongy changes in the periaqueductal area, which resulted in aqueduct stenosis. Later stages (after 20 days post-injection) showed that these edematous changes totally subsided, leaving an obliterated aqueduct which was similar to that of human congenital hydrocephalus. At the completely obliterated area, ultrastructural investigation disclosed a normal-looking neuropil but no aqueductal lumen. In the remaining ependymal cells, increased intermediate filaments and lipid droplets occurred. These data suggest that acute ependymal cell degeneration during the perinatal period may result in the profile of aqueduct “agensis” in human congenital hydrocephalus.
Laser ultrasonics for defect detection and residual stress measurement of friction stir welds

The laser-ultrasonic technique is investigated for defect detection and sizing as well as for residual stress measurement in welds obtained by friction stir welding (FSW). When combined with the Fourier domain synthetic aperture focusing technique, very good performances are achieved for detecting lack of penetration in butt joints, the detection limit coinciding with the conditions of reduced mechanical properties. Also, the detection of kissing bonds seems to be possible in lap joints when probing with ultrasonic frequencies up to 200 MHz. Residual stresses induced by the FSW process can also be probed by laser ultrasonics. The method is based on monitoring the velocity change of the laser-generated surface skimming longitudinal wave, propagating just below the surface and being found much more sensitive to stress. The residual stress profile measured across the weld line is in good agreement with results from a finite element model and from strain gauge measurements.
Al(OH)3‐ and AlO(OH)‐based cocatalysts for metallocene complexes in alkene polymerization reactions

Catalyst systems containing metallocene compounds and methylalumoxane (MAO) are widely used for the polymerization of ethylene and 1-alkenes and for the copolymerization of various alkenes. This note describes alternative cocatalysts for metallocene complexes: combinations of AlMe3 and one of two inorganic aluminum compounds, Al(OH)3 and AlO(OH). The efficiency of the cocatalysts can be increased through the reaction of AlMe3 and the inorganic aluminum compounds at increased temperatures or through the ultrasonic treatment of the cocatalyst mixtures.
Effects of [Ca2+] and [Mg2+] on the decay of miniature endplate currents.

THE endplate current at the neuromuscular junction is initiated by the combination of acetylcholine (ACh) with its receptor. The current rises rapidly to a maximum, and then decays exponentially1. The rate of decay of the endplate current (e.p.c.) depends on membrane potential; hyperpolarisation lengthens the decay phase2,3. A plausible hypothesis for this is that the rate of disassociation of the ACh from the receptor depends on the voltage gradient through the membrane4. The membrane potential consists of three components: the voltage gradient through the membrane itself and the surface potentials at the two membrane–solution interfaces. The surface potentials are thought to be negative, owing to an excess of negatively-charged groups on the membrane phospholipids. An elevation in the divalent ion concentration in the extracellular solutions reduces the negativity of the external surface potential, either by binding to the phospholipids or by screening the charges. A lowering of the negativity of the external surface potential leads to a corresponding increase in the voltage gradient within the membrane (over shorter periods than for phospholipid flip-flop to occur). This leads to the prediction that alterations in the extracellular [Ca2+] or [Mg2+] are likely to change the time course of the e.p.c. Our experiments were designed to test this hypothesis.
Effects of cycloheximide on influx across the brush border of rabbit small intestine

1. 1. Unidirectional influxes of Na+, Cl−, alanine, 3-O-methylglucose and mannitol across brush border of ileum and of iron across brush border of duodenum were determined in normal and cycloheximide-pretreated rabbits. 2. 2. Unidirectional influx of all solutes, with the exception of mannitol, was significantly reduced by cycloheximide administration. Mannitol influx was unaffected. 3. 3. The inhibitory effect of cycloheximide on alanine influx was attributable, almost exclusively, to a 70% reduction in maximal alanine influx. 4. 4. These results are consistent with the notion that cycloheximide inhibits the synthesis of protein(s) directly or indirectly involved in carrier-mediated transport across the brush border of mature, villus absorptive cells.
High-contrast deep-submicron e-beam lithography process for fabricating planar waveguide optical gratings on GaAs

Increased interest in fabricating deep submicron gratings for diffractive optics has resulted in stronger emphasis on higher performance processing techniques. Gratings with well formed line space dimensions of less than 0.3 micron are needed to fill most applications for planar waveguide gratings on GaAs. Electron beam tools of even modest beam energy have little difficulty in patterning isolated deep submicron features. However, patterns of closely spaced features with dimensions of less than 0.4 micron line and space on GaAs suffer increasingly greater contrast degradation because of the interproximity effect. Higher beam energies or enhanced contrast processing becomes necessary. Higher contrast development techniques may extract more information from the latent image and perhaps provide better process latitude, given the same electron beam pattern generation equipment that was suitable for larger size features. In this paper, MIBK and Cellosolve acetate based developers are investigated for processing areal features and grating patterns down to 0.1 micron line and space dimensions. A Leica Instruments Electron Beam Microfabrication tool EBMF 10.5 was used at 30 keV beam energy to pattern PMMA resist on host Gallium Arsenide substrates. Samples were prepared by a thorough cleaning, followed by a dehydration bake and spin coating of PMMA (496 K mw). A two part softbake regimen was performed to promote adhesion. Lithography was done with close attention given to beam current, spot size and machine calibration to insure that all samples were patterned identically. No post bake is necessary for PMMA. Latent images were then developed in different developers. MIBK based developers in dilution of 1:1, 1:2 and 1:3 with isopropyl alcohol were examined for determination of dose to clear and dose latitude.
Drosophila Smad2 Opposes Mad Signaling during Wing Vein Development

In the vertebrates, the BMP/Smad1 and TGF-β/Smad2 signaling pathways execute antagonistic functions in different contexts of development. The differentiation of specific structures results from the balance between these two pathways. For example, the gastrula organizer/node of the vertebrates requires a region of low Smad1 and high Smad2 signaling. In Drosophila, Mad regulates tissue determination and growth in the wing, but the function of dSmad2 in wing patterning is largely unknown. In this study, we used an RNAi loss-of-function approach to investigate dSmad2 signaling during wing development. RNAi-mediated knockdown of dSmad2 caused formation of extra vein tissue, with phenotypes similar to those seen in Dpp/Mad gain-of-function. Clonal analyses revealed that the normal function of dSmad2 is to inhibit the response of wing intervein cells to the extracellular Dpp morphogen gradient that specifies vein formation, as measured by expression of the activated phospho-Mad protein. The effect of dSmad2 depletion in promoting vein differentiation was dependent on Medea, the co-factor shared by Mad and dSmad2. Furthermore, double RNAi experiments showed that Mad is epistatic to dSmad2. In other words, depletion of Smad2 had no effect in Mad-deficient wings. Our results demonstrate a novel role for dSmad2 in opposing Mad-mediated vein formation in the wing. We propose that the main function of dActivin/dSmad2 in Drosophila wing development is to antagonize Dpp/Mad signaling. Possible molecular mechanisms for the opposition between dSmad2 and Mad signaling are discussed.
Effects of physical activity on cognition, well-being, and brain: Human interventions

This article provides a review of the human intervention literature that has examined the influence of fitness training on cognition, well-being, brain structure, and brain function. Meta-analyses of this literature, which are reviewed here, suggest robust effects of fitness training on cognition and well-being. Although there are currently few human intervention studies that have examined fitness effects on human brain function and structure, the studies that have been conducted report promising results.
Lipid deposition and utilization in the sagebrush lizard, Sceloporus graciosus: its significance for reproduction and maintenance.

Abstract 1. 1. Seasonal cycling of lipids in fat bodies, carcass, tail and eggs was observed in female Sceloporus graciosus. 2. 2. Lipids from fat bodies are mobilized for metabolism during hibernation, while remaining fat body lipids and other depot lipids are used, in part, for egg production. 3. 3. Experimental comparisons of rates of lipid utilization and deposition indicated that fat bodies were mobilized the most rapidly and the tail the least rapidly.
Enzymolysis of sclerotized cuticle from Periplaneta americana and Sarcophaga bullata

Abstract The masking of amino acid and glycosyl residues in sclerotized cuticle has been assessed from the ratio of the sites cleaved to the total such sites present. In Periplaneta , trypsin, pepsin, collagenase, papain, Panprotease, and Pronase hydrolysed less than 3 per cent of the available linkages. Subtilisin achieved 5 to 7 per cent cleavage but the fragments remained resistant. Sarcophaga was more readily split by proteases but the native chitin was not made more available to chitinase by prior treatment with proteases. Cuticle glucosyl was localized in glycogen, while mannosyl and galactosyl linkages were resistant to both α - and β -glycosidases. The high order of resistance to enzymolysis suggests generalized protection by hydrogen bond formation during the dehydration that features sclerotization.
Radiolytic Protein Surface Mapping

Abstract We report that high energy beta particles may function as a means for mapping the surface of a protein. Comparable to Fe-EDTA in the presence of ascorbate and peroxide, 90 Y-EDTA alone can break polypeptide backbone bonds on the surface of E. coli RNA polymerase. The two methods give very similar fragmentation patterns, although some unique fragments are produced by each. Radiolytic footprinting may prove useful for mapping proteins inside living cells, since beta-radiolysis produces reactive species up to ≈1 cm away from the emitting 90 Y.
Somatic diversification of IgH genes in rabbit.

Summary: Rabbits have helped elucidate one of the major immunologic puzzles, namely the genetic control of antibody diversity. The primary IgH antibody repertoire in rabbits is dominated by B cells that use the same germline VH-gene segment in VDJ gene rearrangements. The VDJ genes of essentially all B lymphocytes undergo somatic diversification within the first few weeks of the rabbit's life. Such diversification occurs both by a somatic gene conversion-like mechanism as well as by somatic hyper-pointmutation. The diversification that occurs early in ontogeny takes place in gut-associated lymphoid tissues and potentially depends on external factors such as microbial antigens. Few, if any. new B lymphocytes develop in adult rabbits and we discuss how the antibody repertoire is maintained throughout life. Finally, we discuss the molecular mechanism of somatic gene conversion of Ig genes, including die possibility that this involves the use of RAD5 1, an enzyme required for gene conversion-mediated mating type switch in yeast.
SEASONAL VARIATION IN SUN‐SHADE ECOTYPES OF PLECTONEMA NOTATUM (CYANOPHYTA)1

Clonal cultures of the thermophilic alga Plectonema notatum Schmidle were grown from cells collected in winter from the surface and subsurface zones of the cell mat in Jerry Johnson Hot Spring, Idaho. Both surface and subsurface clones exhibited light saturation curves and concentrations of photosynthetic pigments typical of ecotypes highly adapted to shade environments. These winter clones were compared to surface and subsurface clones collected during summer months. This comparison illustrates the seasonal rotation of ecotypes. The shade adapted winter surface and subsurface types dominated the mat during the low light intensity, short photoperiod winter season. With increasing light intensities and photoperiods the winter ecotypes were replaced by the high light intensity adapted summer ecotypes.
Linear-time dynamics for multibody systems with general joint models

Most current linear-time forward dynamics algorithms support only simple types of joints due to difficulties in computing derivatives of joint transformations up to order two. We apply the D* symbolic differentiation algorithm to a recursive formulation of forward dynamics to get a highly efficient linear-time forward dynamics algorithm supporting multibody systems with general scleronomic joints. With this new algorithm we can easily build a tree-topology multibody system with complex joint models and perform forward dynamics efficiently. The source code for the algorithm is freely available for non-commercial use.
Design for Sustainability – Demands for the Integrated Performance of Buildings

Since a few years sustainable construction is a main topic in civil engineering. Including the operation phase the construction sector is the biggest consumer of natural resources, i.e. material, energy and soil surface. Whereas energy consumption for heating and cooling is now part of nearly all planning guidelines developers, architects and structural engineers do not consider resource efficiency, maintenance, dismantling and recycling with adequate significance. Life cycle design is growing driven by economic aspects. Recently real estate consultants have discovered the added value of certificates for sustainable buildings. But an assessment in platin or gold (LEED, DGNB) has to be planned beginning with the project development stage. The pre-condition for it is the declared intention of owners and developers and the early forming of an integrated planning team (architect, structural engineer, consulting engineers, FM etc.). A brief survey of the basic demands for sustainable design of buildings is presented.
Laboratory evaluation of the Hughes 256 x 256 hybrid PtSi imaging device

The Hughes Aircraft Company CRC-365 is a hybrid infrared focal plane array that features a 256 x 256 array of platinum silicide photodiodes. The device was tested in a laboratory environment to determine its performance limits, in the context of medium wave IR imaging. Test results included the dc transfer function of the multiplexer, power dissipation, dark current, thermal barrier height, Schottky barrier height, blackbody response, saturation charge, signal contrast, Schottky quantum yield, temporal noise, noise-equivalent temperature difference, response nonuniformity, temporal drift, and minimum resolvable temperature difference. Overall, performance was found to be excellent. Using two-point nonuniformity correction, background-noise-limited photodetection was achieved for a 40-deg target temperature range. Notable problem areas included bandwidth limitations and electrical crosstalk.
Chronic gnawing induced by electrolytic lesions dorsolateral and lateral to the lateral hypothalamus.

Abstract Electrolytic lesions were placed dorsolateral and lateral to the lateral hypothalamic feeding center in rats. Rats typically showed an initial weight loss followed either by stabilization at reduced weight levels or a gradual return to normal. There was no evidence of hyperphagia. However, these animals showed exaggerated gnawing behavior as measured by the food crumbs accumulating under their cages, averaging 21.3 gm/day, as compared to 5.4 gm/day for normal controls.
REVERSE COMMUTATION IN A MONOCENTRIC CITY

. A general equilibrium multiperiod linear programming model of urban land use is used to identify reverse commutation as a rational response to economic change. Information about future economic conditions is complete, and capital is replaceable at finite cost. Export mixes are defined exogenously, and temporal shifts between activities of different land intensities are shown to induce reverse commutes as one way of avoiding the cost of land use change.
Gamete Fusion Is Required to Block Multiple Pollen Tubes from Entering an Arabidopsis Ovule

In double fertilization, a reproductive system unique to flowering plants, two immotile sperm are delivered to an ovule by a pollen tube. One sperm fuses with the egg to generate a zygote, the other with the central cell to produce endosperm. A mechanism preventing multiple pollen tubes from entering an ovule would ensure that only two sperm are delivered to female gametes. We use live-cell imaging and a novel mixed-pollination assay that can detect multiple pollen tubes and multiple sets of sperm within a single ovule to show that Arabidopsis efficiently prevents multiple pollen tubes from entering an ovule. However, when gamete-fusion defective hap2(gcs1) or duo1 sperm are delivered to ovules, as many as three additional pollen tubes are attracted. When gamete fusion fails, one of two pollen tube-attracting synergid cells persists, enabling the ovule to attract more pollen tubes for successful fertilization. This mechanism prevents the delivery of more than one pair of sperm to an ovule, provides a means of salvaging fertilization in ovules that have received defective sperm, and ensures maximum reproductive success by distributing pollen tubes to all ovules.
A Field-Coherence Technique for Meteorological Field-Program Design for Air Quality Studies. Part I: Description and Interpretation

Abstract This paper describes a new methodology developed to provide objective guidance for cost-effective siting of meteorological observations on the mesoscale for air quality applications. This field-coherence technique (FCT) is based on a statistical analysis of the mesoscale atmospheric structure defined by the spatial and temporal“coherence” in the meteorological fields. The coherence, as defined here, is a measure of the distance scale over which there is temporal consistency in the spatial structure within a variable field. It indicates how well a measurement taken at one location can be used to estimate the value of that field at another location at a given analysis time. The FCT postulates that, the larger the field coherence is, the fewer measurement sites are needed to resolve adequately the dominant characteristics of that field. Proof of concept was demonstrated using real data from an extensive field-program database over the San Joaquin Valley in the summer of 1990. The FCT next was applie...
INTESTINAL COMPLICATIONS FOLLOWING ACCELERATED FRACTIONATED X-IRRADIATION An experimental study in the rat

Due to paucity of suitable animal models, it has been difficult to study the development of long-term intestinal complications following fractionated irradiation. We recently developed a model which allows multiple radiation exposures of a short segment of rat ileum without the need for repeated surgery. In the present series, this model was used to study the influence of shortening the total treatment time (accelerated fractionation) on development of radiation enteropathy. Male rats were orchiectomized and a short segment of distal ileum was transposed to the scrotum. Starting 3 weeks after surgery, the scrotum containing the intestinal segment was x-irradiated with 20 fractions of 2.8 Gy (total dose 56 Gy). Two fractionation schedules were compared: One fraction per day (total treatment time 26 days) and 3 fractions per day (total treatment time 7 days). Actuarial survival curves were obtained, and the degree of radiation injury was assessed 2, 8, and 26 weeks after the last radiation exposure using a ...
COLONIAL GROWTH OF MYCOPLASMA GALLISEPTICUM OBSERVED WITH THE ELECTRON MICROSCOPE

Abstract Shifrine, Moshe (University of California, Davis), Jack Pangborn, and Henry E. Adler. Colonial growth of Mycoplasma gallisepticum observed with the electron microscope. J. Bacteriol. 83:187–192. 1962.—Mycoplasma gallisepticum strain S6 was grown on collodion film on solid medium. Samples were removed every few hours, fixed, washed, shadowed, and observed with the electron microscope. Three distinct forms of growth were observed: elementary cells (hexagonally shaped), platycytes, and exoblasts. A tentative mode of growth was postulated. The significance of the angular morphology to the relation between mycoplasmas and L-forms of bacteria is discussed.
Measurement of 90Sr in reactor wastes by Cerenkov counting of 90Y

Determination of 90Sr in low-level radioactive wastes (LLW) from reactors is difficult because of the presence of so many other radionuclides in samples of interest. This problem was dealt with by radiochemical separation of strontium followed by yttrium separation and Cerenkov counting of the high-energy β-particle emissions of 90Y in order to quantitate 90Sr. Separation of this important nuclide in low-level waste samples was by solvent extraction using tri-n-butyl phosphate. Since most beta emitters in LLW from commercial nuclear power facilities are below about 1 MeV, Cerenkov counting with a high-discriminator setting provided accurate quantitation without interference of potential contaminants which were either removed by separation or discriminated against by the counting procedure. A tracer of 85Sr was used and the radiochemical yield was 59.6 ± 1.9%; the lower limit of detection was found to be 1.48 pCi/g based on a 10 g sample and a 20-min counting time.
Multiple motion segmentation with level sets

Segmentation of motion in an image sequence is one of the most challenging problems in image processing, while at the same time one that finds numerous applications. To date, a wealth of approaches to motion segmentation have been proposed. Many of them suffer from the local nature of the models used. Global models, such as those based on Markov random fields, perform, in general, better. In this paper, we propose a new approach to motion segmentation that is based on a global model. The novelty of the approach is twofold. First, inspired by recent work of other researchers we formulate the problem as that of region competition, but we solve it using the level set methodology. The key features of a level set representation, as compared to active contours, often used in this context, are its ability to handle variations in the topology of the segmentation and its numerical stability. The second novelty of the paper is the formulation in which, unlike in many other motion segmentation algorithms, we do not use intensity boundaries as an accessory; the segmentation is purely based on motion. This permits accurate estimation of motion boundaries of an object even when its intensity boundaries are hardly visible. Since occasionally intensity boundaries may prove beneficial, we extend the formulation to account for the coincidence of motion and intensity boundaries. In addition, we generalize the approach to multiple motions. We discuss possible discretizations of the evolution (PDE) equations and we give details of an initialization scheme so that the results could be duplicated. We show numerous experimental results for various formulations on natural images with either synthetic or natural motion.
Assessing Children's Physical Activity in Their Homes: The Observational System for Recording Physical Activity in Children–Home

The present study describes the development and pilot testing of the Observation System for Recording Physical Activity in Children-Home version. This system was developed to document physical activity and related physical and social contexts while children are at home. An analysis of interobserver agreement and a description of children's physical activity in various settings are presented. The system, which was shown to be reliable, provides a direct observation tool for researchers who are interested in assessing and intervening in physical activity in the home environment.
Performance evaluation of silicon-carbide MOSFET in three-phase high-power-factor rectifier

A high-voltage silicon-carbide (SiC) power MOSFET was evaluated on two high-power factor (HPF), three-phase resonant rectifiers; a non-isolated, 2-kW buck rectifier and an isolated, 3-kW two-switch forward rectifier. By replacing an IGBT switch with a SiC power MOSFET switch that has an equivalent current rating, the efficiency of both the non-isolated and isolated resonant rectifiers were significantly improved. The non-isolated buck rectifier using SiC MOSFET switches could deliver approximately 80%-40% more power than the rectifier using equivalent IGBT switches. Moreover, the efficiency of the isolated two-switch forward rectifier, which was operating with full load and switching frequency of 67 kHz, was improved by approximately 2% when IGBT switches were replaced by SiC power MOSFET switches. The IGBT loss was approximately 4.5% of the total output power. The loss of the SiC MOSFET was only 2.5% of the total output power under the same operating condition. When the prototype circuit was modified to operate at twice the switching frequency, the rectifier using SiC MOSFET switches could deliver approximately 60% more power than the rectifier using equivalent IGBT switches.
Use of item response theory to understand differential functioning of DSM-IV major depression symptoms by race, ethnicity and gender.

Background. Psychological literature and clinical lore suggest that there may be systematic differences in how various demographic groups experience depressive symptoms, particularly somatic symptoms. The aim of the current study was to use methods based on item response theory (IRT) to examine whether, when equating for levels of depression symptom severity, there are demographic differences in the likelihood of reporting DSM-IV depression symptoms. Method. We conducted a secondary analysis of a subset (n=13753) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) dataset, which includes a large epidemiological sample of English-speaking Americans. We compared data from women and men, Hispanics and non-Hispanic Whites, African Americans and Whites, Asian Americans and Whites, and American Indians and Whites. Results. There were few differences overall, although the differences that we did find were primarily limited to somatic symptoms, and particularly appetite and weight disturbance. Conclusions. For the most part, individuals responded similarly to the criteria used to diagnose major depression across gender and across English-speaking racial and ethnic groups in the USA.
A reformulation of the Linear-Quadratic-Gaussian stochastic control problem for application to low thrust navigation analysis

The formulation of the classical Linear-Quadratic-Gaussian stochastic control problem as employed in low thrust navigation analysis is reviewed. A reformulation is then presented which eliminates a potentially unreliable matrix subtraction in the control calculations, improves the computational efficiency, and provides for a cleaner computational interface between the estimation and control processes. Lastly, the application of the U-D factorization method to the reformulated equations is examined with the objective of achieving a complete set of factored equations for the joint estimation and control problem.
Nuclease Activities of Mycoplasma gallisepticum as a Function of Culture Age in Different Media

Levels of deoxyribonuclease and ribonuclease activities in the supernatant (soluble plus ribosomes) fraction of Mycoplasma gallisepticum were assayed and found to be a function of strain, nutrient, and culture age. In yeast hydrolysate-enriched broth, maximal nuclease activities occurred during exponential growth.
Evaluation of the influence of alcohol dehydrogenase polymorphisms on alcohol elimination rates in African Americans.

INTRODUCTION: The relationship between alcohol dehydrogenase (ADH) polymorphisms and alcohol use disorders in populations of African descent has not been clearly established. This study examined the effect of ADH1B polymorphisms on alcohol metabolism and subjective response, following intravenous (IV) alcohol administration, and the influence of gender, recent drinking history, and family history of alcoholism (FHA), in nondependent African American drinkers. MATERIALS: The sample included eighty-seven 21- to 35-year-old, light social drinkers of African descent. Participants included 39 sib pairs, 2 sibships with 3 siblings each, and 3 individuals who were not part of a sibship. Participants received infusions via the use of the clamp method that refers to the goal of controlling breath alcohol concentration in 2 randomized sessions at 0.06 g% ethanol and 0 mg% (placebo), and a battery of subjective scales at predefined time points. Dependent measures included alcohol elimination rates (AERs), alcohol disappearance rates (ADRs), subjective measures peak scores, and area under the curve. General linear model and mixed models were performed to examine the relationship between ADH1B genotype, dependent measures, and influence of covariates. RESULTS: Participants with ADH1B1/1 genotypes showed higher number of drinks (p = 0.023) and drinks per drinking day (p = 0.009) compared with the persons with ADH1B1/3 genotype. AER (adjusted for body weight) was higher in ADH1B*1 homozygotes (p = 0.045) compared with ADH1B1/3 heterozygotes. ADR differed significantly between males and females (p = 0.002), regardless of body weight (p = 0.004) and lean body mass (p Language: en
Investigating the effects of tic suppression on premonitory urge ratings in children and adolescents with Tourette's syndrome

Tics represent a complex class of behaviors that have a neurobiological origin and are influenced by factors both internal and external to the individual. One factor that has gained recent attention is the premonitory urge. Contemporary behavioral models suggest that some tics are preceded by aversive somatic urges that increase in severity when tics are suppressed and are attenuated by performance of the tic. It has been proposed that the removal of premonitory urges may strengthen or maintain tics via negative reinforcement. This investigation is the first to empirically evaluate the effect of tic suppression on the premonitory urge phenomenon. Five children and adolescents, ages 8–17 years, participated in the study. Using an ABAB reversal design, tic frequency and subjective premonitory urge ratings were recorded under conditions of free-to-tic baseline (BL) and reinforced tic suppression (differential reinforcement of zero-rate behavior). Results show that four of the five children demonstrated reliable suppression. Of the four children who achieved suppression, three demonstrated a pattern in which subjective urge ratings were higher during suppression than during BL. Results provide preliminary support for the negative reinforcement view of tic function for some children. r 2007 Elsevier Ltd. All rights reserved.
Acute lung injury and the acute respiratory distress syndrome: a clinical review

Acute respiratory distress syndrome and acute lung injury are well defined and readily recognised clinical disorders caused by many clinical insults to the lung or because of predispositions to lung injury. That this process is common in intensive care is well established. The mainstay of treatment for this disorder is provision of excellent supportive care since these patients are critically ill and frequently have coexisting conditions including sepsis and multiple organ failure. Refinements in ventilator and fluid management supported by data from prospective randomised trials have increased the methods available to effectively manage this disorder.
Using a Pseudoscience Activity to Teach Critical Thinking

In two studies, we assessed the effectiveness of a classroom activity designed to increase students’ ability to think critically. This activity involved watching and discussing an infomercial that ...