cssi/SciSciGPT-SciSciNet huggingface dataset:
THE SYNTHESIS AND TURNOVER OF RAT LIVER PEROXISOMES II. Turnover of Peroxisome Proteins

After preliminary experiments had established that the injection of Triton WR-1339 necessary for the separation of lysosomes and peroxisomes did not affect the turnover rate of catalase, the decay of 3H-leucine incorporated into peroxisomes was studied in whole particles and in protein subfractions. It was shown that peroxisomes are destroyed in a completely random way, probably as wholes since the apparent half-life was the same for all subfractions, about 3½ days. In agreement with the results of Price et al. (11), the half-life of catalase derived from the rate of recovery from aminotriazole inhibition was about 11½ days, as was the apparent half-life of the heme prosthetic groups measured with 14C-α-aminolevulinic acid. Guanidino-labeled arginine gave an apparent half-life of 2½ days with large statistical uncertainty. Either the leucine label was reutilized very extensively in our animals and the true half-life of peroxisomes is 1½ days, or the prosthetic groups of catalase turn over more rapidly than the protein part of the molecule.
Pointer analysis: haven't we solved this problem yet?

During the past twenty-one years, over seventy-five papers and nine Ph.D. theses have been published on pointer analysis. Given the tomes of work on this topic one may wonder, “Haven'trdquo; we solved this problem yet?'' With input from many researchers in the field, this paper describes issues related to pointer analysis and remaining open problems.
Wild Bumblebee (Bombus) Diversity and Nosema (Microsporidia: Nosematidae) Infection Levels Associated with Lowbush Blueberry (Vaccinium angustifolium) Production and Commercial Bumblebee Pollinators

The primary objective was to determine if the prevalence of Nosema bombi infection is higher for wild bumblebees (Bombus spp.) caught in lowbush blueberry growing areas with a history of commercial bumblebee use than for bumblebees caught in areas without a history of commercial bumblebee use. Additionally, we wished to determine relative Bombus species abundances and diversity in blueberry growing regions. Over two years we caught, identified to species, and dissected 767 bumblebees. Light microscopy revealed overall infection levels of 5.48%. The history of commercial bumblebee use had no relation to infection levels. Bumblebee species diversity and field location had significant relationships to infection ( adjusted = 0.265; species diversity , ; field region , ). The absence or presence of one species, Bombus terricola, appears to determine the relationship between species diversity and infection. The data show B. terricola decline in sampled regions and almost half of the collected B. terricola were infected with Nosema. The commercial species, B. impatiens, shows an increase in abundance, but with a 6.9% proportion infection. Molecular confirmation of the infecting species was ambiguous, suggesting a need for future clarification of the infecting species.
XPoint cache: scaling existing bus-based coherence protocols for 2D and 3D many-core systems

With multi-core processors now mainstream, the shift to many-core processors poses a new set of design challenges. In particular, the scalability of coherence protocols remains a significant challenge. While complex Network-on-Chip interconnect fabrics have been proposed and in some cases implemented, most of industry has slowly evolved existing coherence solutions to meet the needs of a growing number of cores. Industries' slow adoption of Network-on-Chip designs is in large part due to the significant effort needed to design and verify the system. However, simply scaling bus-based coherence is not straightforward either because of increased contention and latency on the bus for large core counts. This paper proposes a new architecture, XPoint, which does not need to modify existing bus-based snooping coherence protocols to scale to 64 core systems. XPoint employs interleaved cache structures with detailed floorplaning and system analysis to reduce contention at high core counts. Results show that the XPoint system achieves, on average, a 28× and 35× speedup over a single core design on the Splash2 benchmarks for a 32 and 64 core system respectively (a 1.6× improvement over a 64 core conventional bus). XPoint is also evaluated as a 3D stacked system to reduce further bus latency. Results show a 29× and 45× speedup for 32 and 64 core systems respectively (a 2.1× improvement over a 64 core conventional bus and within 8% of the speedup of a 64 core system with an ideal interconnect). Measurements also show that the XPoint system decreases bus contention of a 64 core system to only 13% higher than that of an 8-core design (a 29× improvement over a 64 core conventional bus).
Parallel computation of the continuous wavelet transform

Parallel algorithm to compute the continuous wavelet transform is presented. The parallel computation uses the LINDA paradigm.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Insecticide resistance in mosquitofish of the Lower Rio Grande valley of Texas—An ecological hazard?

Acute toxicity tests using mosquitofish showed that a population from the Lower Rio Grande Valley of Texas has developed resistance to toxaphene and DDE but not to pyrethroid insecticides. Tests with progeny from resistant parents showed that the F1 generation was also resistant. Resistant mosquitofish bioaccumulate large body residues of organochlorine pesticides that apparently cause no problems for mosquitofish. However, consumption of resistant fish may be hazardous to fish or avian predators and may be one factor contributing to an overall population decline of some species in southern Texas.
Analogous behavior of homogeneous, rotating fluids and stratified, non‐rotating

It has been pointed out in the past that analyses of homogeneous, rotating fluids (system S) and stratified, non-rotating fluids (system S) lead to the same mathematical problem in certain circumstances. The analogy is explored here for the case of steady, linear two-dimensional flows where the temperature variations imposed along side boundaries drive the stably stratified flow and swirl or zonal velocity imposed at the top and bottom boundaries drive the rotating flow. In the fluid S buoyancy boundary layers exist near the side boundaries and these serve the same function in adjusting the temperature between boundary and interior values that the Ekman layer serves to adjust the zonal velocity in the rotating case. The mathematical properties of the two layers are identical. In system S any changes which take place in the interior and tend to alter the stratification are resisted just as changes in the interior which tend to alter the vertical vorticity are resisted in system ?. Processes which give rise to changes in the interior are concentrated in the boundary layers. Simple problems are worked out which exhibit the analogous behavior for two-dimensional systems driven by symmetric and by anti-symmetric conditions imposed at the boundaries. The temperature in the interior of the stratified fluid is the average of the imposed boudary values. This means that with symmetric driving temperatures the fluid is simply restratified by the imposed conditions and with anti-symmetric boundary values the temperature of the fluid interior is unchanged. Buoyancy boundary layers are necessary to adjust interior to boundary temperatures in the latter case. The rotating system has an analogous behavior. In three dimensions the analogy breaks down. The reason is that the third dimension in system S does not involve the constraint and therefore is literally an added degree of freedom whereas in system ? the third dimension also involves the constraint. The difference between the two systems is exhibited by an analysis of the three-dimensional stratified problem with symmetric and anti-symmetric boundary conditions. The symmetric problem in system S differs qualitatively from both the two-dimensional case and the rotating fluid problem. The three-dimensional problem in system ? is qualitatively similar to the two-dimensional one. DOI: 10.1111/j.2153-3490.1967.tb01485.x
A closer look at the "Protopithecus" fossil assemblages: new genus and species from Bahia, Brazil.

The recently extinct large-bodied New World monkey Protopithecus brasiliensis Lund 1836 was named based on a distal humerus and proximal femur found in the Lagoa Santa cave system in the southeastern Brazilian state of Minas Gerais. These bones are from an animal about twice the size of the largest extant platyrrhines. One hundred and seventy-five years later, a nearly complete skeleton was discovered in the Toca da Boa Vista caves in the neighboring state of Bahia and was allocated to the same taxon as it was the first platyrrhine fossil of comparable size found since the originals. Our detailed study of the equivalent elements, however, reveals important morphological differences that do not correspond to intraspecific variation as we know it in related platyrrhine taxa. The presence of both an expanded brachioradialis flange on the humerus and gluteal tuberosity on the femur of the Bahian skeleton distinguishes it from the Lagoa Santa fossil as well as from all other platyrrhines. Further cranial and postcranial evidence suggests a closer relationship of the former with the alouattine Alouatta, while the limited Lund material fits more comfortably with the ateline clade. Therefore, we propose to limit P. brasiliensis Lund to the distal humerus and proximal femur from Lagoa Santa and erect a new genus and species for the skeleton from Toca da Boa Vista. Cartelles coimbrafilhoi was a large-bodied frugivore with a relatively small brain and diverse locomotor repertoire including both suspension and climbing that expands the range of platyrrhine biodiversity beyond the dimensions of the living neotropical primates.
Shear Stress Intensity Factors for a Planar Crack With Slightly Curved Front

Recent work (Rice, 1985a) has presented the calculations of the first order variation in an elastic displacement field associated with arbitrary incremental planar advance of the location of the front of a half-plane crack in a loaded elastic full space. That work also indicated the relation of such calculations to a three-dimensional weight function theory for crack analysis and derived an expression for the distribution of the tensile mode stress intensity factor along a slightly curved crack front, to first order accuracy in the deviation of the crack front location from a reference straight line. Here we extend the results on stress intensity factors to the shear modes, solving to similar first order accuracy for the in-plane [Mode 2) and antiplane (Mode 3) shear stress intensity factors along a slightly curved crack front. Implications of results for the configurational stability of a straight crack front are discussed. It is also shown that the concept of line tension, while qualitatively useful in characteriz­ ing the crack extension force (energy release rate) distribution exerted on a tough heterogeneity along a fracture path as the crack front begins to curve around it, does not agree with the exact first order effect that is derived here.
Comment on ``Stability of conductance oscillations in monatomic sodium wires''

The discussion in a recent paper by Khomyakov and Brocks [Phys. Rev. B 74, 165416 (2006)] suggests that it is the use of a uniform-background (jellium) model for the electrodes, which are linked by a short chain of Na atoms, in Lang [Phys. Rev. Lett. 79, 1357 (1997)] that leads to a calculated conductance for the Na wire appreciably smaller than the quantum unit (particularly for the one-atom wire), in disagreement with experiment. These calculations, however, used electrodes with a fairly high electron density, roughly that of Al, and so they should not be expected to reproduce the results of experiments that are more appropriately modeled using electrodes whose density corresponds to that of Na (which is much lower than that of Al).
Don’t Blame the Computer: When Self-Disclosure Moderates the Self-Serving Bias

When consumers use computers to help make purchase decisions, how do they attribute responsibility for the positive or negative outcomes of those decisions? The results suggest that, in general, attributions of responsibility reflect a self-serving bias: Consumers tend to blame computers for negative outcomes and tend to take personal credit for positive ones. However, the results also suggest that, when consumers have a history of intimate self-disclosure with a computer, this pattern of attribution is significantly mitigated: Consumers are more willing to credit the computer for positive outcomes, and are more willing to accept responsibility for negative outcomes. In addition, this research provides evidence that the causal relation between self-disclosure and attributions of responsibility is partially mediated by attraction.
Applications of accelerator mass spectrometry to electronic materials

Abstract Applications of accelerator mass spectrometry (AMS) to stable-element detection in electronic materials are being explored. Conventional AMS hardware at the University of Arizona has been used to profile shallow semiconductor structures (ion-implanted samples) and to establish minimum values of system efficiency for several ions in Si and/or GaAs. A custom instrument under development at the University of North Texas has been used to generate molecule free mass spectra which can be directly compared with secondary-ion mass spectrometry (SIMS) data. Elemental fragments associated with molecular dissociation after passage through the accelerator are shown to constitute a source of system “background” which can be removed through clever selection of charge states.
Apolipoprotein E4 Domain Interaction Accelerates Diet-Induced Atherosclerosis in Hypomorphic Arg-61 Apoe Mice

Objectives— Apolipoprotein (apo) E4 is an established risk factor for atherosclerosis, but the structural components underlying this association remain unclear. ApoE4 is characterized by 2 biophysical properties: domain interaction and molten globule state. Substituting Arg-61 for Thr-61 in mouse apoE introduces domain interaction without molten globule state, allowing us to delineate potential proatherogenic effects of domain interaction in vivo. Methods and Results— We studied atherosclerosis susceptibility of hypomorphic Apoe mice expressing either Thr-61 or Arg-61 apoE ( Apoe T h/h or Apoe R h/h mice). On a chow diet, both mouse models were normolipidemic with similar levels of plasma apoE and lipoproteins. However, on a high-cholesterol diet, Apoe R h/h mice displayed increased levels of total plasma cholesterol and very-low-density lipoprotein as well as larger atherosclerotic plaques in the aortic root, arch, and descending aorta compared with Apoe T h/h mice. In addition, evidence of cellular dysfunction was identified in peritoneal Apoe R h/h macrophages which released lower amounts of apoE in culture medium and displayed increased expression of major histocompatibility complex class II molecules. Conclusions— These data indicate that domain interaction mediates proatherogenic effects of apoE4 in part by modulating lipoprotein metabolism and macrophage biology. Pharmaceutical targeting of domain interaction could lead to new treatments for atherosclerosis in apoE4 individuals.
Evidence of only one H-2D/L-related glycoprotein in H-2dm1 mutant cells.

SUMMARY Analyses of the H-2D/L-related glycoproteins from dm1 mutant cell extracts by sequential immunoprecipitation, by SDS gel electrophoresis and by tryptic peptide mapping indicate that dm1 cells express only a single glycoprotein with H-2D/L-related determinants. In contrast to the four H-2D/L-related antigens identified for the parental d haplotype viz. H-2Dd, H-2Md, H-2Ld and H-2Rd, separate and distinguishable “H-2Ddm1”, “H-2Mdm1”, “H-2Ldm1” and “H-2Rdm1” glycoprotein counterparts are apparently lacking in the dm1 mutant haplotype. Only a single H-2D/L-related glycoprotein is identified in dm1 extracts by standard serological methods and this glycoprotein is designated H-2D/Ldm1 because of its H-2Dd/H-2Ld hybrid characteristics, as recently shown by Burnside and colleagues (1984). Thus, the seemingly complex phenotype of the dm1 mutant appears to originate primarily from one molecule having properties of two (or more) molecules of the parental haplotype.
Flavor of Microwave- and Conventionally-Reheated Turkey

Abstract INTRODUCTION USE of precooked, frozen turkey products is increasing in both institutions and homes, primarily because they are convenient and economical. Often, undesirable flavors and aromas are observed in reheated turkey. In general, as meat flavor deteriorates, it loses its fresh, sweet, meaty-brothy flavor, and becomes neutral-flavored (Jones, 1960). With further deterioration, sourness and bitterness may develop, followed by staleness and, finally, rancidity. Stale and rancid flavors in meat have been explained partially by oxidation of unsaturated fatty acids in muscle tissue (Watts, 1962). Because turkey muscle contains more such lipids than other meats do, it is more susceptible to flavor deterioration. Microwaves heat meat much faster than gas or electric heat sources do. Since lipid oxidation is accelerated by exposure to heat, it was of interest to determine if less flavor deterioration occurred with microwave than conventional heating. The purpose of this study was to compare turkey reheated by…
The brain-derived neurotrophic factor receptor TrkB is critical for the acquisition but not expression of conditioned incentive value

Stimuli paired with reward acquire incentive properties that are important for many aspects of motivated behavior, such as feeding and drug-seeking. Here we used a novel chemical-genetic strategy to determine the role of the brain-derived neurotrophic factor (BDNF) receptor TrkB, known to be critical to many aspects of neural development and plasticity, during acquisition and expression of positive incentive value by a cue paired with food. We assessed that cue's learned incentive value in a conditioned reinforcement task, in which its ability to reinforce instrumental responding later, in the absence of food itself, was examined. In TrkB (F616A) knock-in mice, TrkB kinase activity was suppressed by administering the TrkB inhibitor 1NMPP1 during the period of initial cue incentive learning only (i.e. Pavlovian training), during nose-poke conditioned reinforcement testing only, during both phases, or during neither phase. All mice acquired cue-food associations as indexed by approach responses. However, TrkB (F616A) mice that received 1NMPP1 during initial cue incentive learning failed to show conditioned reinforcement of nose-poking, regardless of their treatment in testing, whereas administration of 1NMMP1 only during the testing phase had no effect. The effects of 1NMPP1 administration were due to inhibition of TrkB(F616A), because the performance of wild-type mice was unaffected by administration of the compound during either phase. These data indicate that BDNF or NT4 signaling through TrkB receptors is required for the acquisition of positive incentive value, but is not needed for the expression of previously acquired incentive value in the reinforcement of instrumental behavior.
Trench-parallel flow and seismic anisotropy in the Mariana and Andean subduction systems

Shear-wave splitting measurements above the mantle wedge of the Mariana1 and southern Andean2,3 subduction zones show trench-parallel seismically fast directions close to the trench and abrupt rotations to trench-perpendicular anisotropy in the back arc. These patterns of seismic anisotropy may be caused by three-dimensional flow associated with along-strike variations in slab geometry1,2,3,4,5. The Mariana and Andean subduction systems are associated with the largest along-strike variations of slab geometry observed on Earth6,7 and are ideal for testing the link between slab geometry and solid-state creep processes in the mantle. Here we show, with fully three-dimensional non-newtonian subduction zone models, that the strong curvature of the Mariana slab and the transition to shallow slab dip in the Southern Andes give rise to strong trench-parallel stretching in the warm-arc and warm-back-arc mantle and to abrupt rotations in stretching directions that are accompanied by strong trench-parallel stretching. These models show that the patterns of shear-wave splitting observed in the Mariana and southern Andean systems may be caused by significant three-dimensional flow induced by along-strike variations in slab geometry.
Disruption of the active site solvent network in carbonic anhydrase II decreases the efficiency of proton transfer

The importance of maintaining the active site water network for efficient proton transfer was investigated by substituting amino acids of varying size at position 65 in carbonic anhydrase II (including four amino acids found in other CA isozymes, F, L, S, and T, and two amino acids that do not occur naturally at position 65, G and H) and measuring the rate constants for the proton transfer reactions in the variant carbonic anhydrases. Intramolecular proton transfer between zinc-bound water and H64 is significantly inhibited by the introduction of bulky residues at position 65; kcat for CO2 hydration decreases up to 26-fold, comparable to the observed decrease in intramolecular proton transfer caused by removal of H64 [Tu, C., Silverman, D. N., Forsman, C., Jonsson, B.-H., & Lindskog, S. (1989) Biochemistry 28, 7913-7918]. Intermolecular proton transfer between protonated H64 and external buffer is also inhibited, although to a lesser degree. Furthermore, an alternative proton transfer pathway, consisting of an active site solvent-mediated proton transfer from zinc-water to imidazole buffer, is inhibited in the A65F, A65L, and A65H CAII variants. Therefore, the active solvent bridge between zinc-bound water and H64 is disrupted by substitutions at position 65. The inhibition of proton transfer reactions correlates with the disruption of the crystallographically observed solvent network in the CA active site and rotation of the proton acceptor, H64 [Scolnick, L. R., & Christianson, D. W. (1996) Biochemistry 35, 16429-16434], suggesting that this solvent network, including water molecules 292, 264, and 369, or a structurally related network, forms the proton transfer pathway in CAII for both intramolecular proton transfer and stimulation of proton transfer in imidazole buffers.
Reactive oxygen species and the hypomotility of the gall bladder as targets for the treatment of gallstones with melatonin: a review

Free radical-mediated damage of the gall bladder epithelium predisposes to the development of both gall bladder inflammation and gallstone formation, which often coexist. Melatonin, a pineal and gut secretory product, due to its antioxidant activity along with its effect on the aging gall bladder myocytes, inhibits gallstone formation. Melatonin reduces the biliary levels of cholesterol by inhibiting cholesterol absorption across the intestinal epithelium and by increasing the conversion of cholesterol to bile acids. The incidence of gallstones is increasing and is expected to rise dramatically with the increase in the longevity and the risk factors such as obesity. The change in the prevalence of cholelithiasis is associated with a proportionate rise in the incidence of cholangiocarcinoma. In an attempt to improve the quality of life of the rapidly increasing aging population, this article reviews up-to-date information on the pathophysiology of the gall bladder function and discusses the development of new therapies with potential good patient compliance and lower cost than the current treatments.
Potential therapeutic role of glutamate transporter 1 for the treatment of alcohol dependence.

Introduction Evidence has demonstrated that deficits in glutamate transmission impair neurocircuits involved in drug abuse or drug-seeking behaviour and affect many aspects of neuroplasticity associated with alcohol and drug addiction. Alcohol-seeking behaviour is promoted by increased glutamate transmission in key regions of the mesocorticolimbic reward circuit, including the nucleus accumbens and prefrontal cortex. Glutamate transmission or glutamate uptake is regulated by a number of glutamate transporters in the brain regions. Among these glutamate transporters, glutamate transporter 1 (GLT1; its human homolog is the excitatory amino acid transporter 2, EAAT2) regulates the removal of majority of the extracellular glutamate. The role of GLT1 has been tested in alcohol and other drugs of abuse models with dysfunction in glutamate transmission. We recently reported that treatment of alcohol-preferring rats with compounds ceftriaxone and GPI-1046, known to upregulate GLT1 levels, showed reduction in alcohol intake and attenuation of relapse-like ethanol-drinking behaviour. Furthermore, we demonstrated that upregulation of GLT1 was associated with attenuation of cue-induced cocaine relapse. Together, we suggest that GLT1 is considered as a potential therapeutic target for the treatment of drug dependence, including alcohol. The aim of this critical review was to discuss the potential therapeutic role of GLT1 for the treatment of alcohol dependence. Conclusion Dysfunction of glutamate transmission has been suggested to impair neurocircuits involved in alcohol dependence, which affect neuroplasticity that is associated with ethanol intake.
High-frequency limit of the bremsstrahlung spectrum

The bremsstrahlung cross-section at the high-frequency limit of the spectrum has been evaluated to the first three nonvanishing orders inαZ for high-energy incident electrons. The power series inαZ which occurs in the cross-section apparently converges rapidly enough to yield accurate results over a wide range of values ofZ. The values obtained for the cross-section are somewhat smaller than those predicted by the lowest-order (Fano) theory and are in good agreement with recent experimental measurements.
Operational regimes of rich methane and propane/oxygen flames in mesoscale non-adiabatic ducts

Abstract An experimental investigation was conducted of the oscillatory flames observed in narrow circular ducts in order to determine the mode of oscillation as a function of equivalence ratio and flow speed for fuel-rich methane–oxygen and propane–oxygen mixtures. In order to study flame stabilization in narrow ducts of diameter on the order of the quenching diameter, premixed fuel and oxygen were burned in an optically accessible straight quartz tube with an inner diameter of a few mm, one end of which was open to the atmosphere. Methane–oxygen and propane–oxygen flames were examined and compared, and various oscillating and steady flame formations were observed. It was observed that for methane the boundaries between behavioral regimes were dependent almost exclusively on equivalence ratio, with the boundary equivalence ratio values remaining nearly constant for different Reynolds numbers; for propane the boundaries were dependent on both equivalence ratio and Reynolds number, with the limit equivalence ratio values decreasing with increasing Reynolds number. The effect of tube length on oscillatory behavior and stability was also examined by experimenting in 35, 70, and 210 mm long tubes. Increasing the tube length decreased the stability of oscillations for both fuels, although the effect was less intense for propane. It was also observed that oscillations were only established in mesoscale ducts made of low conductivity materials, a result that was rationalized in terms of the pertaining Biot and Fourier numbers.
Fair Use, Intellectual Property, and New Media

Moderator: Shawn Martin, Scholarly CommunicationsLibrarian, University of PennsylvaniaPanelists: Jack Lerner, Clinical Associate Professor of Law,University of Southern California; Kevin Smith, Sch...
Spatial patterns of overstory trees in late- successional conifer forests

We analyzed spatial patterns of overstory trees in late-successional Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes forests and late-successional Pseudotsuga menziesii (Mirb.) Franco forests ...
Favorable Response to Analgesics Does Not Predict a Benign Etiology of Headache

Background.—Distinguishing between primary and secondary headaches (HAs) is essential for the safe and effective management of patients with HA. A favorable response to analgesics may be observed with both classes of HAs and therefore is not a good predictor of who needs further evaluation. Objective.—To systematically review the data that a favorable response to analgesics including triptans should not be used to exclude a serious secondary cause of HA. Design.—PubMed search of English-language articles between 1980 and 2007 and reference lists of these articles. Two authors independently reviewed articles for study results and quality. Inclusion was based on 100% agreement between authors. We included articles that described secondary HAs as (1) having a favorable response to analgesics and/or (2) having a favorable response to sumatriptan. Of the 548 studies identified by our search strategy, 18 were included in our final analysis. Results.—Seven of the 18 studies found that 46/103 patients (44%) described a significant or complete resolution of secondary HA from medications such as anti-emetics and nonsteroidal anti-inflammatory drugs (NSAIDs). Eleven of the 18 articles including 25/25 patients (100%) described a significant or complete resolution of secondary HA from sumatriptan, a serotonin 5HT agonist. Conclusions.—A favorable response to analgesics including triptans should not be used to exclude a serious secondary cause of HA.
Lack of soybean root elongation responses to micromolar magnesium additions and fate of root-exuded citrate in acid subsoils.

Additions of micromolar concentrations of magnesium (Mg) to hydroponics enhance aluminum (Al) tolerance of soybean by increasing citrate secretion from roots and external complexation of toxic Al species. The objective of this study was to assess the ameliorative effect of Mg additions on soybean root elongation into mineralogically different acid soils. Roots of soybean seedlings grew for 28 days into acid soils treated with three Mg levels in their soil solution (Control, 150 and 300 μM) and lime. Root growth in the acid soils and aboveground dry matter responses to the Mg treatments were less than for the lime treatments. Citrate fate in the acid soils revealed that 66–99% of added citrate was either adsorbed or biodegraded, suggesting that root secreting citrate in the soil abundant with Al and iron (Fe) hydroxides potentially reduces the availability to complex rhizotoxic Al. A calcium (Ca) deficiency may have constrained root growth response to the Mg-treated soils.
A coordinate measuring machine with parallel mechanisms

Widely used in manufacturing industry, coordinate measuring machines(CMM) are traditionally designed with a serial structure, which is composed of a serial chain of three mutually perpendicular prismatic joints to achieve three degrees of freedom in motion. There exist some shortcomings such as error accumulation and low stiffness in this kind of structure. This paper introduces a CMM with a parallel structure, which is more accurate and robust compared to the serial one, and studies some important issues in designing and developing this type of CMM, including the closed-form forward and inverse solutions, workspace analysis, and system calibration.
Vitamin A Status in Mice Affects the Histone Code of the Phosphoenolpyruvate Carboxykinase Gene in Liver

Vitamin A deficiency decreases hepatic phosphoenolpyruvate carboxykinase (PEPCK) gene expression in mice, and expression is restored with retinoic acid (RA) treatment in vivo. In the studies reported here, we examined changes in histone modification and coregulator association with the regulatory domains of the PEPCK gene in response to alterations in vitamin A status. We identified nuclear receptors that bind to retinoic acid response elements (RAREs) in the PEPCK promoter by electrophoretic mobility shift assay and verified these in vivo using chromatin immunoprecipitation in mouse liver. Hypothetically, nuclear receptors at PEPCK RAREs recruit specific coactivator molecules that contribute to the acetylation of core histones and/or serve as bridging molecules between nuclear receptors and basal transcription factors at the transcription start site. We identified 3 coactivator molecules, cAMP-response element binding protein (CBP), steroid receptor coactivator (SRC)-1, and peroxisome-proliferator activated receptor (PPAR)-gamma-coactivator (PGC)-1alpha, that bound in association with the PEPCK RAREs in vivo. Furthermore, there was differential binding of these coactivators in vitamin A-deficient mice. Related to this, specific lysine residues were acetylated on histones H3 and H4 at the 3 RAREs of the PEPCK promoter, consistent with the action of the above coactivators, and acetylation of certain lysines was significantly decreased with vitamin A deficiency. These results demonstrate the associated changes that occur in nuclear receptor binding, coactivator recruitment, and histone acetylation in response to vitamin A status, identified at specific RAREs in the PEPCK gene in vivo.
Catabolite repression in the hyperthermophilic bacterium Thermotoga neapolitana is independent of cAMP.

Thermotoga neapolitana is a hyperthermophilic bacterium whose phylogenetic lineage includes the most primitive of the bacterial heterotrophs. It is not known whether Thermotoga exhibits preferences for growth substrates or regulates the synthesis of degradative enzymes. We have found that T. neapolitana exhibits diauxic growth in medium containing 300 μM glucose and 1 mM lactose. We measured the activity of β-galactosidase and β-glucosidase in extracts prepared from cells grown on defined media and found that cells grown on 0.5% lactose, galactose or cellobiose contained β-galactosidase specific activities of 1.19, 1.78 and 1.34 U (mg protein)-1, respectively. Cells grown on 0.5% glucose, maltose, fructose, sucrose, xylose, ribose or starch had no measurable β-galactosidase activity. β-Glucosidase activity was found only in cells grown on cellobiose. Cells grown on the combination of 0.5% lactose or galactose and 0.05% glucose had no detectable β-galactosidase activity, whereas up to 0.5% glucose did not prevent expression of β-galactosidase or β-glucosidase activity in cells induced with 0.5% cellobiose. These activities are catalysed by separate enzymes as determined by resolution of their activities on 6% native polyacrylamide gels. Therefore, only β-galactosidase synthesis induced by lactose is subject to catabolite repression. To determine the mechanism of catabolite repression, the levels of cAMP were measured in T. neapolitana cells grown on various defined media using an enzyme-immunoassay. The cAMP levels ranged from 44 to 280 fmol (mg protein)-1 irrespective of the carbon source used. By comparison, Escherichia coli grown on lactose contained 5.1 pmol (mg protein)-1. Like Gram-positive bacteria, T. neapolitana displays a cAMP-independent mechanism for catabolite repression and this may represent the more ancient mode of regulation.
Broadcast encryption's bright future

As a vehicle for content protection, broadcast encryption promises more flexible and resilient security compared with traditional public key cryptography techniques.
Plankton and primary production in aquatic systems of the Central Amazon basin

Abstract 1. Three aquatic environments of the Central Amazon Basin were sampled during the low water phase: Rio Solimo˜es (Amazon), Rio Negro and Lago Junauaca´. 2. In the nutrient-rich Rio Solimo˜es, primary productivity averaged 0.063 g C/m2 per day, but net growth of phytoplankton is impossible because of the depth, poor light penetration and current-driven turbulence. 3. In the chemically-poor Rio Negro, a daily cycle of ΣCO2 was caused by photosynthetic demand in surface waters, and primary productivity averaged 0.19 g C/m2 per day. 4. In Lago Janauaca´. a lake bordering the Solimo˜es, nutrients were low in concentration and intensively recycled; large phytoplankton populations produced up to 3.5 g C/m2 per day (average = 2.2). 5. The 10 m annual change in water level of the Amazon River provides and drains most of the water in lakes along the river. During storage of river water in the lakes the particulates settle and the dissolved inorganic nutrients are converted to organic forms by intense phytoplankton growth. These lakes may be a major source of organic matter for the river ecosystem.
Singlet Oxygen Chemistry in Water: A Porous Vycor GlassSupported Photosensitizer

Singlet molecular oxygen [1O2 (1Δg)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by monitoring the time-resolved 1O2 (1Δg) phosphorescence at 1270 nm. Indirect analysis of 1O2 generation was also carried out with the photooxidation of trans-2-methyl-2-pentenoate anion, which afforded the corresponding hydroperoxide. Sensitizer-1-impregnated PVG gives rise to a new singlet oxygen generator but more importantly provides a heterogeneous system for use in water.
Magnetic backprojection imaging of the vascular lumen

Current injected into a phantom model generated a magnetic field which was distorted above a simulated atherosclerotic lesion. The output of a Hall effect magnetic sensor was used in a backprojection to reconstruct the centroid of the simulated blood flow and thus localize the modeled atherosclerotic plaque region. >
Expression and Targeting of Secreted Proteins from Chlamydia trachomatis

ABSTRACT Chlamydia trachomatis is an obligate intracellular pathogen that replicates in a vacuole termed the inclusion. Many of the interactions of chlamydiae with the host cell are dependent upon bacterial protein synthesis and presumably exposure of these proteins to the cytosol. Because of the dearth of genetic tools for chlamydiae, previous studies examining secreted proteins required the use of heterologous bacterial systems. Recent advances in genetic manipulation of chlamydia now allow for transformation of the bacteria with plasmids. We describe here a shuttle vector system, pBOMB4, that permits expression of recombinant proteins under constitutive or conditional promoter control. We show that the inclusion membrane protein IncD is secreted in a type III-dependent manner from Yersinia pseudotuberculosis and also secreted from C. trachomatis in infected cells where it localizes appropriately to the inclusion membrane. IncD truncated of the first 30 amino acids containing the secretion signal is no longer secreted and is retained by the bacteria. Cytosolic exposure of secreted proteins can be confirmed by using CyaA, GSK, or microinjection assays. A protein predicted to be retained within the bacteria, NrdB is indeed localized to the chlamydia. In addition, we have shown that the chlamydial effector protein, CPAF, which is secreted into the host cell cytosol by a Sec-dependent pathway, also accesses the cytosol when expressed from this system. These assays should prove useful to assess the secretion of other chlamydial proteins that are potentially exposed to the cytosol of the host cell.
Intergenerational Equity and Resource Use

. Is it “fair” for one generation to use up, wholly or to a degree, resources which cannot be replaced? By evaluating projects involving non-replaceable resources with discount rates are future benefits undervalued?Discounted net present value is found to be a poor allocator of scarce resources. Another choice rule, Page and Ferejohn's Dominance Rule, also contains flaws. A “partitioned” approach, dividing the time horizon into sections, is an improvement and has advantages. While this third approach has basic uncertainties, it may be used to meet nondeferrable decisions while problems of equity and preference are being studied.
Data in the First Mile

Inmany disadvantaged communities worldwide, local low-resource organizations strive to improve health, education, infrastructure, and economic opportunity. These organizations struggle with becoming data-driven, because their communities still live outside of the reach of modern data infrastructure, which is crucial for delivering effective modern services. In this paper, we summarize some of the human, institutional and technical challenges that hinder effective data management in “first mile” communities. These include the difficulty of deploying, cultivating and retaining expertise; oral traditions of knowledge acquisition and exchange; and mismatched incentives between top-down reporting requirements and local information needs. We propose a set of directions, drawing from projects that we have implemented. They include 1) separating the capture of data from its structuring, 2) applying intelligent automation to mitigate human, institutional and infrastructural constraints, and 3) deploying services in cloud infrastructure, opening up further opportunities for human and computational value addition. We illustrate these ideas in action with several projects, including Usher, a system for automatically improving data entry quality based on prior data, and Shreddr, a hosted paper form digitization service. We conclude by suggesting next steps for engaging in data management problems in the first mile.
Area detectors for neutron protein crystallography

The main problem in neutron protein crystallography is the low flux of present reactor based or pulsed neutron sources. This low flux is however well matched with presently available multiwire area detectors. One way to increase the flux at the sample is to increase the wavelength bandwidth. The conventional technique uses a monochromator with a bandwidth of the order of 1%. This bandwidth can be increased by using a multilayer monochromator composed of different 'd' spacings. This provides a large delta lambda increasing the flux manifold. In this case a reflection in diffraction condition is scanned by the wavelength bandwidth and not by rotation of the reciprocal lattice point through the Ewald sphere. In order to collect most of the simultaneous diffraction a large cylindrical area detector covering an angular width of 120 degree(s) with a height of approximately 20 cm is needed. Such a detector should have a spatial resolution of 1.1 mm, an efficiency of 80% at 2.0 A and a counting rate of one million events per second. This detector will be subdivided into 4 sectors that will be decoded simultaneously into a Motorola based computer system. This data acquisition system allows time slicing and this detector is therefore useful for similar experiments using pulsed neutron sources.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A nonlocally weighted soft-constrained natural gradient algorithm for blind separation of reverberant speech

A nonlocally weighted soft-constrained natural gradient iterative method is introduced for robust blind separation in reverberant environment. The nonlocal weighting of the iterations promotes stability and convergence of the algorithm for long demixing filters. The scaling degree of freedom is controled by softconstraints built into the auxillary difference equations. The small divisor problem of iterations in silence durations of speech is resolved. Computations on synthetic speech mixtures based on measured binaural room impulse responses show that the algorithm achieves higher signal-to-inteference ratio improvement than existing method (natural gradient time domain algorithm) in an office size room with reverberation time over 0.5 second.
Outcomes of reinterventions after subintimal angioplasty

Objective With increased use of subintimal angioplasty (SIA), the role of reintervention after recurrence is currently unknown. To more clearly define the technical feasibility, patency, and clinical outcomes of reinterventions after SIA, we reviewed our cumulative experience. Methods A retrospective review of patient information (including demographics, indications, procedures, noninvasive arterial studies, and postprocedural events) was performed on those patients undergoing reintervention after a primary subintimal angioplasty in the infrainguinal vessels. Continuous and noncontinuous data were compared using the Student t -test and the z test, respectively. Patency was calculated by Kaplan-Meier analysis. Survival curves were compared using log-rank and Wilcoxon testing for univariate analysis and Cox hazard-regression analysis for multivariate analysis. Results From December 2002, through July 2006, 495 SIAs were performed for infrainguinal disease in 482 patients. Of this cohort, 121 patients (25%) required 188 consecutive reinterventions. Each patient underwent an average of 1.5 ± 0.8 (range, 1-7) reinterventions during this study. We analyzed only the outcomes of 124 consecutive, first reinterventions. Mean interval time between primary SIA and the first reintervention was 7.8 ± 6.8 months (range, 1 day-31 months). Indications for reintervention were clinical only (recurrence of symptoms or worsening exam), diagnostics only (recurrence based on peripheral vascular lab studies), or both in 18%, 25%, and 52% of patients, respectively. Technical success was achieved in 94% (n = 117) of the procedures. Repeat SIA technique was utilized in 68% (n = 84) of reinterventions and other endovascular therapies (32%; n=40), of which the majority were transluminal angioplasty, for the remaining reinterventions. Mean follow-up was 8.6 months (range, 0-34 months). The patency rate at 1 year for the first reintervention was 33%. One-year patency rates for reinterventions performed within 3 months of the primary SIA were worse than those performed after 3 months (22% vs 34%; P = .04). In addition, patients treated for claudication had better 1-year patency than those treated for critical limb ischemia (37% vs 27%; P = .03). Other demographic or procedural variables did not significantly affect patency. In patients with critical limb ischemia (CLI), limb salvage rate at 1 year was 71%. Conclusion Endovascular reintervention after SIA is a safe and technically feasible procedure for recurrences and offers good limb salvage rate. Early reinterventions performed within 3 months of the original SIA portend a worse outcome. In addition, reinterventions are less durable in patients with CLI compared with claudication. Finally, by identifying a recurrent stenosis instead of an occlusion, close surveillance may contribute to improved overall outcome.
Making empirical progress in observational ecology

Epistemology, the theory of how knowledge arises, is an issue that ecologists and environmental scientists may not often consider in their work. However, beliefs about epistemology play a direct role in how they conduct research and, consciously or not, the conclusions made through analysis reflect some form of epistemology. I argue that the Popperian epistemology by which most environmental scientists are trained is generally incompatible with research on observational data and that observation-based studies can be improved by modifying Popper's notion of falsification.