cssi/SciSciGPT-SciSciNet huggingface dataset:
The predictor-corrector technique of track following

Abstract Track images of bubble chamber events are circular to a good approximation provided the optics are simple. All the early versions of track following algorithms in use with automatic measuring machines thus assumed circularity of the images to predict subsequent points of digitization. With the advent of large chambers and fish eye optics, track images are no longer circular and all the existing algorithms experience great difficulty in track following such images. In what follows, a method is described that does not assume circularity of the tracks. The algorithm may be easily generalized to as high order polynomials as required and is reversible. All that is assumed is that the tracks are continuous and differentiable.
Enhanced electron transfer activity of photosystem I by polycations in aqueous solution.

The use of proteins in advanced nanotechnological applications requires extended stabilization of the functional protein conformation and enhanced activity. Here we report that simple cationic poly...
Smad3 and Pitx2 cooperate in stimulation of FSHβ gene transcription

Abstract Activin is a member of the TGFβ superfamily of growth and differentiation factors that control a variety of cellular and physiological functions. The canonical intracellular pathway of this ligand is well established and involves Smad signaling molecules. The tissue- and cell-specificity of activin action is achieved by Smad interaction with various transcriptional co-factors in the nucleus. In the reproductive axis, activin induces biosynthesis and secretion of follicle stimulating hormone (FSH) through transcriptional control of FSHβ-subunit. Whereas it has been well demonstrated that this regulation is mediated by Smad pathway, the molecular mechanisms underlying gonadotrope-specific expression of the FSHβ gene are not fully understood. Previously, we have identified Pitx2 as a pituitary-expressed transcription factor involved in activin-dependent induction of the FSHβ promoter. Present data demonstrate that Pitx2 is not only sufficient, but also necessary for FSHβ gene transcription, as a siRNA-mediated downregulation of Pitx2 protein expression abrogates both Smad3- and activin-mediated stimulation of the FSHβ promoter. In addition, downregulation of Smad3 protein expression has a significant effect on Pitx2-dependent stimulation of the FSHβ promoter, suggesting that cooperation between these factors is necessary for full transcriptional activation of the FSHβ promoter. Furthermore, we show that Pitx2/Smad protein complexes assemble and can be co-immunoprecipitated. This interaction is mediated through the homeodomain of Pitx2 and is important for stimulation of FSHβ gene transcription. Overall, these data contribute to the emerging molecular mechanism underlying both basal and activin-dependent FSHβ gene regulation.
Evaluation of a solid-state photodiode-array spectrometer with optical-feedback stabilization

Abstract An optical-feedback system is adapted for stabilization of a rapid-scanning spectrometr based on a solid-state photodiote array detector and its performance is evaluated. A beam-splitter is used to divert a fraction of source intensity to a phototransistor, the signal from which is used to control the output from a programmable power supply that controls source intensity. Any tendency for source intensity to change with time is compensated by the feedback systems. The system reduces effects of short-term and long-term drift by more than an order of magnitude relative to the same system without optical feedback. Other features of the system including stray light and linearity are evaluated.
Calculation of hydraulic conductivities of horizons in some major soils in Wisconsin

Abstract Hydraulic conductivity between saturation and a tension of 100 cm water was calculated with moisture-retention data for nine soil horizons and compared with results from in situ measurements with the crust test. Agreement was good for sandy, apedal soil horizons with simple packing voids but only if matching factors were used. Results were unreliable in clayey, pedal soil horizons in which a few relatively large planar and tubular pores determine K in the measured tension range, whereas the greatest fraction of total porosity is composed of fine pores inside peds that hardly contribute to flow. Varying the number of pore classes (n) and the water-filled porosity at saturation made no significant difference in the calculations for the apedal soils, but drastically changed the shape of the calculated curves for the pedal soils. Matching factors based on Ksat measurement had to be used for all studied soil horizons, indicating that Marshall's pore-interaction model never predicted Ksat accurately.
Concentration-dependent accumulation of [3H]-deltamethrin in sodium channel Nav1.2/β1 expressing Xenopus laevis oocytes

Disruption of neuronal voltage-sensitive sodium channels (VSSCs) by pyrethroid insecticides such as deltamethrin (DLT) has been widely studied using Xenopus laevis oocytes transfected with VSSC. However, the extent of pyrethroid accumulation in VSSC-expressing oocytes is unknown. Therefore, accumulation of [(3)H]-DLT in non-transfected, sham (water)-transfected and VSSC (Na(v)1.2+beta(1))-transfected oocytes after a 1h exposure was measured using liquid scintillation counting. Successful transfection of Na(v)1.2+beta(1) VSSCs in X. laevis oocytes was confirmed by two-electrode voltage-clamp; inward, tetrodotoxin (TTX)-sensitive currents were obtained in 98% of all oocytes examined (n=60 in nine experiments). DLT (1.0 microM) induced tail currents in all VSSC-transfected oocytes; TTX also blocked these DLT-induced tail currents. In 0.1 microM DLT solution, non-transfected oocytes accumulated 0.098+/-0.01 ppm [(3)H]-DLT, sham-transfected oocytes accumulated 0.06+/-0.01 ppm DLT, and VSSC-transfected oocytes accumulated 0.050+/-0.009 ppm DLT. In 1.0 microM DLT solution, non-transfected oocytes accumulated 0.62+/-0.08 ppm DLT, sham-transfected oocytes accumulated 0.60+/-0.09 ppm DLT, and VSSC-transfected oocytes accumulated 0.51+/-0.07 ppm DLT. There was a significant difference in DLT accumulation between VSSC-transfected oocytes and non-transfected controls, where the transfected oocytes consistently had less accumulation.
The influence of bretylium on the action of reserpine and McNeil-A-343.

Abstract Injection of bretylium into rats produced little or no change in content of catecholamines in heart; reserpine produced a marked decrease. The depletion of catecholamines caused by reserpine was reduced or abolished after pretreatment of the animals with bretylium. Bretylium depressed the increase in arterial blood pressure and cardiac phosphorylase a activity produced by administration of McNeil-A-343.
Meta-Analyses of ALDH2 and ADH1B with Alcohol Dependence in Asians.

Meta-analyses were conducted to determine the magnitude of relationships between polymorphisms in 2 genes, ALDH2 and ADH1B, with alcohol dependence in Asians. For each gene, possession of 1 variant *2 allele was protective against alcohol dependence, and possession of a 2nd *2 allele did not offer significant additional protection. The protective effects of these 2 gene polymorphisms were independent. Diagnostic criteria, recruitment strategy, and Japanese ethnicity moderated the effect of ALDH2*2. Recruitment strategy and gender moderated the effect of ADH1B*2. These findings highlight the importance of methodological issues and potential gene-gene and gene-environment interactions that must be considered when examining relationships between genetic polymorphisms and phenotypes.
Molecular volume determines the activity of the halogenated alkane bromoform at wild-type and mutant GABAA receptors

The GABA(A) receptor is an important target for a variety of general anesthetics, including halogenated ethers such as isoflurane and halogenated ethers such as chloroform. Bromoform is a halogenated alkane that exhibits anesthetic properties and has been shown by X-ray crystallography to bind to model anesthetic targets. In this study we report the ability of bromoform to potentiate GABA-induced current in recombinant GABA(A) receptors composed of alpha(1)beta(2)gamma(2s) subunits. Recent studies have shown that specific point mutations in the transmembrane (TM) region of the GABA(A) receptor alpha-subunit can selectively abolish the modulatory activity of specific general anesthetics, and that molecular volume is a key determinant of anesthetic activity. The action of bromoform was examined in a series of mutant receptors and compared with the activity profiles of three other volatile anesthetics. The pharmacological profile of bromoform at the mutant receptors used in this study was similar to that seen with halothane, and distinct from that observed for isoflurane and chloroform. The molecular volume of bromoform is closest to that of halothane, and therefore our data are consistent with the idea that molecular volume is an important determinant of inhaled anesthetic activity at the GABA(A) receptor.
Two novel mutations of the vasopressin gene associated with familial diabetes insipidus and identification of an asymptomatic carrier infant.

Familial diabetes insipidus (FDI) is a syndrome of central vasopressin deficiency that is inherited in an autosomal dominant manner and that typically becomes clinically apparent in the first decade of life. Two novel mutations of the vasopressin gene have been identified in two previously unstudied kindreds with FDI. In each kindred, the inheritance of the FDI phenotype was consistent with an autosomal dominant mode of inheritance. In each proband, the diagnosis of central diabetes insipidus had been confirmed previously with a water deprivation protocol. After extraction of genomic DNA from each individual, the three exons of the vasopressin gene were separately amplified by PCR and directly sequenced using an automated dye termination method. In the proband and two other carriers of one kindred, a heterozygous C to T mutation was identified at nucleotide 1857. This is predicted to produce a serine to phenylalanine substitution at residue 56 of the vasopressin-related neurophysin peptide encoded by the ...
Arginine 25 and Arginine 28 of lactoferrin are critical for effective heparin neutralization in blood.

Abstract The interaction of lactoferrin with endogenous heparin-like molecules modulates glycosaminoglycan-mediated biological processes. We performed site-specific mutagenesis and expressed recombinant lactoferrin and lactoferrin mutants by the baculovirus insect cell expression system. Five basic residues at the lactoferrin N terminus; Arg 5, Arg 25, Arg 28, Lys 29, and Arg 31, were individually replaced by alanines. Heparin chromatography on fast-performance liquid chromatography system showed that the NaCl concentrations corresponding to the peak of each eluted recombinant protein from the column were 665, 620, 540, 550, 630, or 650 mM for wild-type recombinant lactoferrin, Arg 5, Arg 25, Arg 28, Lys 29, or Arg 31 recombinant lactoferrin mutant, respectively. We compared the ability of each mutated lactoferrin derivative to neutralize glycosaminoglycans in the thrombin serpin inhibition assays. In comparison to wild-type recombinant lactoferrin, all the mutants showed decreased ability to neutralize glycosaminoglycan in a dose-dependent manner. The mutations of lactoferrin at Arg 25 and Arg 28 demonstrated the most striking decrease in lactoferrin’s ability to neutralize various glycosaminoglycans in both enzymatic and plasma clotting-based experiments. Therefore, our results suggest that Arg 25 and Arg 28 are the critical basic residues at the lactoferrin N terminus responsible for heparin binding. The other basic residues on the N terminus, Arg 5, Lys 29, and Arg 31, also contribute to heparin binding by presenting an additional cationic motif.
Improving Supervisor Evaluations Through the Use of Self Determination Contracts

Supervisor perceptions of employee competence in areas of work, social, and personal demands of the job often determine success or failure for the supported employee. This study involved three work...
A plastid segregation defect in the protozoan parasite Toxoplasma gondii

Apicomplexan parasites—including the causative agents of malaria (Plasmodium sp.) and toxoplasmosis (Toxoplasma gondii)—harbor a secondary endosymbiotic plastid, acquired by lateral genetic transfer from a eukaryotic alga. The apicoplast has attracted considerable attention, both as an evolutionary novelty and as a potential target for chemotherapy. We report a recombinant fusion (between a nuclear-encoded apicoplast protein, the green fluorescent protein and a rhoptry protein) that targets to the apicoplast but grossly alters its morphology, preventing organellar segregation during parasite division. Apicoplast-deficient parasites replicate normally in the first infectious cycle and can be isolated by fluorescence-activated cell sorting, but die in the subsequent host cell, confirming the ‘delayed death’ phenotype previously described pharmacologically, and validating the apicoplast as essential for parasite viability.
Monovalent Inactivated A/New Jersey/8/76 (Hsw1N1) Vaccine in Healthy Children Aged Three to Five Years

Single doses (50, 100, or 200 chick cell-agglutinating [CCA] units) of split-product or whole-virus (50 or 100 CCA units), monovalent inactivated A/New Jersey/8/76 (Hsw1n1) virus vaccine or placebo were given to healthy children aged three to five years in Maryland. Split-product vaccine was nonreactogenic but also virtually nonimmunogenic. Lower doses of whole-virus vaccine (50 CCA units of Merck, Sharp and Dohme [West Point, Pa.] and 50 or 100 CCA units of Merrell-National Laboratories [Cincinnati, Ohio] vaccine) were mildly reactogenic (approximately 25% of the children had low-grade fevers of 100 F-101 F). These dosage levels of whole-virus vaccine stimulated titers of greater than or equal to 1:20 in 68% and titers of greater than or equal to 1:40 in 37% of the children. Two inoculations of whole-virus vaccine (primary immunization followed by a booster one month later) were tolerated and induced titers of greater than or equal to 1:80 in 100% of the children.
Exploring Dynamic Redundancy to Resuscitate Faulty PCM Blocks

DRAM technology challenges have increased the necessity to adapt to the emerging memory technologies like Phase-Change Memory (PCM or PRAM). While such emerging technologies provide benefits like storage density, nonvolatility, and low energy consumption, they are constrained by limited write endurance that becomes more pronounced with process variation. In this article, we explore a novel PRAM-based main memory system which resuscitates a group of faulty pages in a cost-effective manner to significantly extend the PCM main memory lifetime while minimizing the performance impact. In particular, we explore three different dimensions of dynamic redundancy levels and group sizes, and design low-cost hardware and software support for our proposed schemes. We aim to have minimal hardware modifications (that have less than 1p on-chip and off-chip area overheads). Also, our schemes can improve the PRAM lifetime by up to 105× (times) over a chip with no error correction capabilities, and outperform prior schemes such as DRM and ECP at a small fraction of the hardware cost. The performance overhead resulting from our scheme is less than 8p on average across 21 applications from SPEC2006, Splash-2, and PARSEC benchmark suites.
Skin grafts for the salvage of degloved below-knee amputation stumps

We present a series of six patients in whom a traumatic below-knee amputation was associated with significant degloving, such that there was inadequate local skin to achieve primary stump closure. In each case, skin grafts were used to cover the stump muscle flaps. The patients ranged in age from 21 years to 73 years; the mean hospital stay was 72 days and the mean follow-up was 48 months. Despite an average of five procedures to achieve stump healing and an average of 118 days to first limb fitting, all patients have achieved independent mobility with their prosthesis. All have had minor stump problems necessitating periods of time off their prosthesis. Three patients have required minor stump-revision surgery. The advantages of a below-knee amputation over an above-knee amputation compensate for these problems. The forgiving nature of modern prostheses has contributed to acceptable results in these patients, who had what may previously have been considered insufficiently durable stump cover.
A Genome-wide Study Reveals Copy Number Variants Exclusive to Childhood Obesity Cases

The prevalence of obesity in children and adults in the United States has increased dramatically over the past decade. Genomic copy number variations (CNVs) have been strongly implicated in subjects with extreme obesity and coexisting developmental delay. To complement these previous studies, we addressed CNVs in common childhood obesity by examining children with a BMI in the upper 5th percentile but excluding any subject greater than three standard deviations from the mean in order to reduce severe cases in the cohort. We performed a whole-genome CNV survey of our cohort of 1080 defined European American (EA) childhood obesity cases and 2500 lean controls (< 50th percentile BMI) who were genotyped with 550,000 SNP markers. Positive findings were evaluated in an independent African American (AA) cohort of 1479 childhood obesity cases and 1575 lean controls. We identified 17 CNV loci that were unique to at least three EA cases and were both previously unreported in the public domain and validated via quantitative PCR. Eight of these loci (47.1%) also replicated exclusively in AA cases (six deletions and two duplications). Replicated deletion loci consisted of EDIL3, S1PR5, FOXP2, TBCA, ABCB5, and ZPLD1, whereas replicated duplication loci consisted of KIF2B and ARL15. We also observed evidence for a deletion at the EPHA6-UNQ6114 locus when the AA cohort was investigated as a discovery set. Although these variants may be individually rare, our results indicate that CNVs contribute to the genetic susceptibility of common childhood obesity in subjects of both European and African ancestry.
Measurement of differential rupture durations as constraints on the source finiteness of deep-focus earthquakes

[1] The physical mechanism of deep earthquakes can be constrained by identifying their fault planes. Resolving the fault plane ambiguity is a classical problem in seismology, and we present a method to distinguish the fault plane using observations of source finiteness. Source finiteness is observable on seismograms at different azimuths and distances, for single-event ruptures, as variations in the apparent rupture duration and, for complex ruptures, as differences in the traveltime delay between subevents. For each earthquake, the rupture duration (or traveltime delay) will be shortest in the direction of rupture propagation and longest in the opposite direction. Rather than measuring the actual rupture duration at each station, we use a cross-correlation technique that includes a stretching factor to measure the differential rupture duration between each pair of stations. These differential measurements then allow us to identify the rupture direction, rupture velocity, and fault plane for each earthquake. First, we test the method on two synthetic earthquakes, which represent earthquakes composed of one and two events. The method works well for both examples, although attenuation can bias the determined rupture direction for the single-event case. Next, we apply this method to P waves from broadband seismograms from four intermediate- and deep-focus earthquakes composed of two subevents: the 23 January 1997 Bolivian earthquake (MW 7.1, 276 km depth), the 27 October 1994 earthquake south of the Fiji Islands (MW 6.7, 549 km depth), the 21 July 1994 Japan Sea earthquake (MW 7.3, 471 km depth), and the 11 November 1998 Fiji Islands earthquake (MW 6.3, 149 km depth). Each focal mechanism contains a subvertical and a subhorizontal nodal plane. For three of the events, our analysis shows that rupture propagated subhorizontally, and we identify the subhorizontal nodal plane as the fault plane. For the smallest event, the rupture azimuth, but not the rupture dip, is well constrained, and we cannot conclusively identify the fault plane. Rupture velocities vary from 0.18 to 0.63 of the local P wave velocity.
The location of the feature [continuant] in feature geometry

Abstract A consensus is emerging from the recent work on the hierarchical representation of phonological features (i.e., on Feature Geometry) by such researchers as Clements (1985), Halle (1986), Sagey (1986b), and Archangeli and Pulleyblank (1986) that, on the one hand, place of articulation features group together under the Place node, and, that, on the other hand, laryngeal features group together under the Laryngeal node. However, there is very little consensus on where manner of articulation features belong. In this paper we focus on the manner of articulation feature [continuant]. After reviewing various proposals concerning the location of [continuant] in Feature Geometry, it is argued based on assimilation and deletion phenomena from the Dravidian language Pengo that [continuant] is located under the Supralaryngeal node.
A discrete approach to designing optimal hedging-point control policies for production-inventory systems with general stochastic behavior

The hedging-point policy for a production-inventory system is investigated under the effect of probabilistic machine breakdowns and repairs assuming general discrete distributions for the repair time and the time to failure. Using a methodology whereby inventory levels can assume only discrete values, an optimal safety stock size that minimizes the total expected cost per unit time is determined.
Aggregation and soil organic matter accumulation in cultivated and native grassland soils

Tillage intensity affects soil structure and the loss of soil organic C and N. We hypothesized that no-tillage (NT) and conventional tillage (CT) differentially affect three physically defined particulate organic matter (POM) fractions. A grassland-derived Haplustoll was separated into aggregates by wet sieving. Free light fraction (LF) and intra-aggregate POM (iPOM) were isolated. Natural abundance 13 C was measured for whole soil C, free LF C, and iPOM C. The mean residence time of soil C under CT (44 yr) was 1.7 times less than in NT (73 yr). The amount of free LF C was 174, 196, and 474 g C m -2 for CT, NT, and NS, respectively. Total iPOM C amounts in CT, NT, and NS were 193, 337, and 503 g C m -2 , respectively. The level of fine iPOM C (53-250 μm) level in macroaggregates (250-2000 μm) obtained after slaking was five times greater in NT vs. CT and accounted for 47.3% of the difference in total POM C between NT and CT. The amount of coarse iPOM C (250-2000 μm) was only 2.4 times greater and accounted for only 21% of the difference in total POM C. Sequestration of iPOM was observed in NT vs. CT, but free LF was not influenced by differential tillage. We conclude that differences in aggregate turnover largely control the difference in fine iPOM in CT vs. NT and consequently SOM loss is affected by both the amount of aggregation and aggregate turnover.
Peroxidase-dependent oxidation of tyrosine or dopa to melanin in neurons

Peroxidase activity was demonstrated in guinea pig frontal lobe by histochemical methods, and was correlated with peroxidase-dependent enzymatic synthesis of melanin from tyrosine or dopa. Peroxidase activity and peroxidase-dependent melanin synthesis appeared to be mainly in lysosomes of neurons. These findings open the possibility that peroxidase may have a role in catecholamine, lipofuscin and neuromelanin synthesis in the brain.
Enhancement of chicken lymphocyte activation and lymphokine release by avian influenza virus.

Abstract We had previously found that inactivated avian influenza virus (AIV) could enhance the response of chicken lymphocytes to mitogen or antigen activation. An investigation into the possible mechanisms of this enhancement was undertaken. Peripheral blood lymphocytes (PBL) were incubated with AIV expressing different hemagglutinin (HA) types (H1–H13) along with doses of concanavalin A (Con A) which induce maximum (0.5 μg) or submaximum (0.125 μg) PBL activation. The lymphocyte activation was measured 72 h later. All of the HA types except H13 enhanced the Con A response. Diminished but significant enhancement could be observed when AIV administration was delayed by as much as 48 h of the 72-h incubation time. The AIV A/ck/Ala/75 (H4N8) was also examined for its effect on interleukin 2 (IL 2) synthesis by Con A-activated PBL and was found to modestly increase the synthesis of this lymphokine. All of the AIV hemagglutinin types agglutinated the PBL with titers slightly lower than that observed for the chicken erythrocyte agglutination. These results indicate that the AIV-induced enhancement of Con A responsiveness by chicken PBL is due, at least partly, to increased synthesis of IL 2 and that the effect may be due to some viral component other than the agglutinin.
Unexpected variation in lignin

Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Pines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. These results argue in favor of an increased potential for genetic modification of lignin and indicate that our knowledge of the biosynthesis of lignin is far from complete.
Human umbilical cord blood-derived mast cells: a unique model for the study of neuro-immuno-endocrine interactions.

Findings obtained using animal models have often failed to reflect the processes involved in human disease. Moreover, human cultured cells do not necessarily function as their actual tissue counterparts. Therefore, there is great demand for sources of human progenitor cells that may be directed to acquire specific tissue characteristics and be available in sufficient quantities to carry out functional and pharmacological studies. A case in point is the mast cell, well known for its involvement in allergic reactions, but also implicated in inflammatory diseases. Mast cells can be activated by allergens, anaphylatoxins, immunoglobulin-free light chains, superantigens, neuropeptides, and cytokines, leading to selective release of mediators. These could be involved in many inflammatory diseases, such as asthma and atopic dermatitis, which worsen by stress, through activation by local release of corticotropin-releasing hormone or related peptides. Umbilical cord blood and cord matrix-derived mast cell progenitors can be separated magnetically and grown in the presence of stem cell factor, interleukin-6, interleukin-4, and other cytokines to yield distinct mast cell populations. The recent use of live cell array, with its ability to study such interactions rapidly at the single-cell level, provides unique new opportunities for fast output screening of mast cell triggers and inhibitors.
Mass balance model estimation of phosphorus concentrations in reservoirs

: Mass balance models have been common tools in lake quality management for some years. However, verification for use on reservoirs, especially in the Western United States, has been seriously lacking, In this study, such a verification is attempted using data from the U.S EPA National Eutrophication Survey. Several models from the literature are compared for accuracy in application to the western reservoir data. Model standard error and correlation between estimated and observed reservoir phosphorus concentrations are the Criteria used for comparison. Standard errors am further used to calculate uncertainty of trophic state classification based on estimated phosphorus concentration. The model proposed by Dillon and Rigler (1974) proved most accurate, with a correlation coefficient of 0.86 and standard error of 0.2, based on logarithmic transformed values. Deficiencies in the other models appear to & from coefficients fit to lake data and from inappropriate model formulation.
Development of the personal aldehydes and ketones sampler based upon DNSH derivatization on solid sorbent

This paper presents the design and evaluation of a tube-type diffusive sampler, the Personal Aldehydes and Ketones Sampler (PAKS). The sampler employs dansylhydrazine (DNSH)-coated solid sorbent to collect aldehydes and ketones (carbonyls). The DNSH-carbonyl derivatives are analyzed using a sensitive HPLC-fluorescence technique. The PAKS was evaluated using test atmospheres containing eight carbonyls for a range of face velocity, temperature, relative humidity, concentration, and sampling duration. The PAKS was also evaluated in the field by comparing results obtained from the PAKS method to those from a conventional DNPH method. The evaluation results indicate that the PAKS is a valid passive sampler for 24−48-h collection of carbonyls in indoor, outdoor, or personal air. The fluorescence detection of DNSH-carbonyl derivatives substantially enhances the sensitivity of the PAKS method as compared to the DNPH method when the sampling rates for the two methods are comparable. The PAKS exposure detection lim...
Monocrotaline pyrrole-induced changes in angiotensin-converting enzyme activity of cultured pulmonary artery endothelial cells.

1 Changes in the structural and functional integrity of endothelium have been recognized as relatively early features of delayed and progressive pulmonary vascular injury caused by the pyrrolizidine alkaloid, monocrotaline (MCT). Although a number of investigators have evaluated angiotensin-converting enzyme (ACE) activity in the lungs of rats treated with MCT, the exact nature of changes in activity of this enzyme and the role they may play in MCT pneumotoxicity remain controversial. 2 We examined the direct effects of monocrotaline pyrrole (MCTP), a toxic metabolite of MCT, on cultured endothelial cell ACE activity. Post-confluent monolayers of porcine or bovine pulmonary artery endothelial cells (PECs or BECs, respectively) were treated with a single administration of MCTP at time 0; then they were examined for their ability to degrade the synthetic peptide, [3H]-benzoyl-Phe-Ala-Pro. 3 In PECs, which are relatively insensitive to the direct cytolytic effects of MCTP, monolayer ACE activity was unchanged initially but gradually decreased within 4 days after treatment with a high concentration of MCTP (150 μm). This decrease was transient, and PEC monolayer ACE activity returned to the control value by 10 days post treatment. 4 BEC monolayer ACE activity was also unchanged initially but rapidly declined within 4 days after MCTP treatment and remained depressed throughout the post treatment period. BECs were quite sensitive to the cytolytic effects of MCTP and the decline in ACE activity occurred coincident with the decrease in monolayer cellularity and appearance of marked cytotoxicity. 5 We conclude that high concentrations of MCTP decrease endothelial ACE activity. The decline in ACE activity is delayed and the magnitude and duration of the decrease corresponds to the degree of MCTP-induced cytotoxicity. This suggests that altered endothelial ACE activity is unlikely to be a direct effect of MCTP on the enzyme but may reflect the delayed cell injury which results from exposure to this compound.
Assessment of a thermoplasticized gutta-percha delivery system to effectively obturate canals with varying preparation dimensions.

Abstract The purpose of this study was to measure the ability of a thermoplasticized-injectable (TPI) gutta-percha (GP) delivery system to fill a prepared root canal to working length and replicate intracanal defects (coronal, middle, apical) as a function of root canal preparations with varying lateral dimensions. Three split-tooth models with 0.06 taper and different apical gauge preparations, 0.30 mm (group A), 0.40 mm (group B), and 0.50 mm (group C), were used. Obturations were evaluated using an ordinal scale (0-4) based on how much each intracanal defect was replicated. Coronal and middle defects were completely replicated 100% of the time, regardless of the preparation. However, there was a significant difference (p ≤ 0.05) between apical defect replication with more accurate replication in groups B and C. There was also a significant difference (p ≤ 0.05) in working length replication; groups A and B, respectively, exhibited 1.20 and 0.52 mm mean underfill, and 0.52 mm mean extrusion was associated with group C. These results suggest group B with a 0.40-mm apical gauge preparation might yield better intracanal defect and working length replication when using TPI GP in the clinical situation.
Historians and American Communism: An Agenda

There have been, Roger Keeran says in the Introduction to his Communist Party and the Auto Workers Unions, three broad assumptions governing the study of the Party's role in labor: "The Communists were not legitimate trade unionists. They were not an important influence in the labor movement. And they were not good Communists."1 These are, he might have added, also rough stages in the historical development of the political analysis which the writers brought to the subject. The hard-bitten Socialist opponents, from Benjamin Stolberg to Irving Howe, could not forgive the Communists' influence on many unions nor forget the "totalitarian" intent which threatened workaday unionism. Their successors, including prominent sociologists and labor and industrial relations theorists, more often tended to brush off the party influence as an incidental to a system which righted itself (after an initial phase of excitement) into corporate-style blocs of in fluence. Then came the New Left scholars of the 1960s-70s. These last affected sympathy for the ultra-revolutionary commitments of the Party in its "Third Pe riod" (1928-35) as against the more liberal Popular Front, for Trotskyism or Spontaneism against the Party's Center-Le ft strategy within the CIO, and in gen eral for a revolutionary alternative that the Party did not represent.2 None of these types of formulations stand up to the evidence, Keeran properly concludes. Now what?
The preparation and chemical characteristics of hemoglobin-free ghosts of human erythrocytes

Abstract The effects of the ionic strength and pH of the hemolyzing solution on the hemoglobin content of human erythrocyte ghosts were studied in phosphate buffers and found to have a pronounced influence upon hemoglobin binding in the ghosts. Buffer concentrations between 10 and 20 ideal milliosmolar (imOsm), at pH values 5.8 – 8.0, resulted in maximum hemoglobin removal from ghosts. The pH optimum for hemoglobin binding to ghosts was between 5.8 and 5.9 in a 20 imOsm buffer. The influence of these variables suggest an electrophysical interaction of hemoglobin with membrane constituents. This study provides a basis for comparison of existing methods for ghost preparation, as well as a means for prediction of the conditions required for preparation of ghosts containing any desired amount of hemoglobin. Conditions were found that allowed the preparation of hemoglobin-free ghosts by single-stage hemolysis and washing. Hemoglobin-free ghosts were prepared in 20 imOsm phosphate buffer at pH 7.4. Essentially all the lipid was recovered in the ghosts, but non-hemoglobin nitrogen-containing substances were lost. The pyridine hemochromogen method for hemoglobin determination was adapted for the measurement of very small quantities of hemoglobin through use of the Soret band (418 mμ) for absorbancy measurements.
On interactional expertise: Pragmatic and ontological considerations

This paper is a critical examination of Harry Collins's investigation into a third form of knowledge, “interactional expertise.” We argue that although Collins makes a genuine contribution to the phenomenological literature on expertise, his account requires further critical evaluation and response due to pragmatic and ontological considerations. We contend that by refining (in some questionable ways) the category of interactional expertise so as to create epistemological equivalence between activists, sociologists, critics, journalists, and some science administrators, Collins potentially undermines the value that a more rigorously construed concept of interactional expertise might have. We further show that Collins misunderstands the nature of embodiment in a way that is exacerbated by the sociological perspective that he adopts.
Operant behavioral analysis of memory loss in monkeys with prefrontal lesions.

Abstract The effects of dorsolateral prefrontal cortical ablation were examined in rhesus monkeys preoperatively trained to perform two versions of an indirect spatial delayed-response task. In one task (DR I), the stimulus keys that signaled the position of the reward were accessible throughout a trial. Thus, the monkeys could orient to the positive side (‘rehearse’) by continuing to press the correct key during the delay. The other task, DR II, was designed to disrupt bodily orientation and to prevent ‘rehearsal’. In this task the monkeys were required to press an extraneous upper key during the delay. After bilateral ablation of the prefrontal cortex, 3 out of the 4 monkeys easily regained preoperative levels of performance on the DR I task, but all subjects were markedly impaired in the DR II task on which they exhibited strong position preferences. These deficits were ameliorated by eliminating the position biases through training with short delay intervals followed by gradual increments in delay length. Analysis of the location of key presses during each phase of delayed-response trials showed that the monkeys press the correct key in the cue period even when they subsequently made incorrect responses. A consistent finding was that operated monkeys shifted their response to the incorrect key early in the delay period regardless of its duration, whenever the correct side was the nonpreferred side. These results support the idea that delayed-response deficits in monkeys with prefrontal lesions may be due in part to a defect in registering or encoding the correct spatial position in memory rather than to a loss in storage or retrieval processes.
Thermodynamic Studies on the Cataract-Associated Mutant, E107a, of Human Gamma-D Crystallin: Molecular Basis for Cataract Formation

The E107A mutation in human gammaD-crystallin (HGD) is associated with nuclear cataract. The concentration of crystallins in the lens is extremely high, approaching that within protein crystals. The composition in the lens nucleus, i.e. the central core, is such that the alpha- and gamma crystallin weight fractions are comparable. In earlier studies we showed that mutations in HGD dramatically compromised protein solubility, while maintaining the overall protein structure. In contrast, in the E107A mutation neither the structure (circular dichroism and tryptophan fluorescence emission) and stability (thermal denaturation), nor the solubility are affected significantly. However, as expected, the mutation raises the pI by ∼1 pH unit, i.e. from 7.4 to 8.4. The increase in pI suggested a change in the interaction of E107A with alpha crystallin, which is negatively charged at neutral pH. To determine changes in such interaction, we compared the liquid-liquid phase boundaries in binary mixtures containing either HGD or E107A, and alpha crystallin. Our preliminary studies show that while the phase-separation temperatures of mixtures in the two cases (i.e. HGD+alpha and E107A+alpha) remain comparable, the nature of the paired compositions of the two phases in equilibrium are distinct. In particular, the tie-line slopes are altered in the direction predicted to correspond to increased alpha-gamma attraction, on the basis of molecular dynamics simulation and thermodynamic perturbation theory (1). Thus, it appears that increased attractive interactions between the E107A mutant of HGD and alpha crystallin could destabilize the crystallin mixture in the lens nucleus, and lead to increased light scattering and cataract.(1) N. Dorsaz, G. M. Thurston, A. Stradner, P. Schurtenberger and G. Foffi, J. Phys. Chem. B 113:1693-1709 (2009)Supported by: NIH Grant EY 18249-01 (G.T.) and EY 10535 (J.P.)
Synthesis and crystal structure refinement of Cu(I)Ti2(PO4)3

Abstract Single crystals of the Nasicon-type compound, Cu(I)Ti 2 (PO 4 ) 3 were grown hydrothermally at 500°C under 3 kbar pressure. The crystal structure was solved by means of single crystal x-ray diffraction and refined to R = 0.027. Although the [Ti 2 P 3 O 12 ] −1 framework in CuTi 2 (PO 4 ) 3 is identical to Zr, P framwork in NaZr 2 (PO 4 ) 3 , the Cu atoms are shifted away from the M1 sites (3) occupied by Na in latter structure. The Cu atoms in CuTi 2 (PO 4 ) 3 are three-fold coordinated and are located near the bottle-neck in the path between M1 and M2 sites of the Nasicon structure.
Optimal recovery paths for perturbations of trophic level bioeconomic systems

Abstract This paper examines optimal recovery paths following perturbations (e.g., El Nino) in a coupled ecosystem. A simple 2-trophic level model is developed in which the harvested species also feeds upon a prey species. As might be expected, it is optimal to refrain from harvesting when both species are severely impacted by the perturbation. Perhaps surprising, however, is the result that it may sometimes be optimal to reduce the harvested species even more following some perturbations. Generally speaking, the less impacted are primary (harvested) species relative to secondary species, the more likely it will be that a pre-recovery harvesting phase is necessary.
A Cross-country Test of the Permanent Income Hypothesis

The Permanent Income Hypothesis (PIH) predicts an income innovation has the same size effect on consumption as on permanent income, an implication we examine with a cross-country test proposed by Kormendi & LaHaye (1984). The data from industrial countries support PIH but data from developing countries do not. Also, however, data from countries with high quality national income accounts support PIH whereas data from countries with low quality accounts do not. The stage of economic development and data quality are highly correlated. The evidence suggests that the results may be driven primarily by data quality differences rather than systematically different behaviour between industrial and developing countries.
Optimized piranha etching process for SU8-based MEMS and MOEMS construction.

We demonstrate the optimization of the concentration, temperature and cycling of a piranha (H2O2:H2SO4) mixture that produces high yields while quickly etching hollow structures made using a highly crosslinked SU8 polymer sacrificial core. The effects of the piranha mixture on the thickness, refractive index and roughness of common micro-electromechanical systems and micro-opto-electromechanical systems fabrication materials (SiN, SiO2 and Si) were determined. The effectiveness of the optimal piranha mixture was demonstrated in the construction of hollow anti-resonant reflecting optical waveguides.
Separation from siblings: Associations with placement adaptation and outcomes among adolescents in long-term foster care

Abstract Although practice guidelines support the placement of siblings in the same foster home whenever possible, sibling groups are frequently separated. Little empirical knowledge is available to understand why siblings are separated or how different sibling placement patterns are related to children's placement adaptation and permanency outcomes. These questions were investigated using data from a study involving telephone interviews with the caseworkers and foster parents of a cross-sectional sample of 197 randomly selected young adolescents in long-term, traditional family foster care. Placement outcomes, including placement disruption, reunification, and adoption, were followed prospectively for five years. Results of multivariate analyses indicate that adolescents who were placed alone after a history of joint sibling placements were at greater risk for placement disruption than those who were placed with a consistent number of siblings while in foster care. This association was mediated by a weaker sense of integration and belonging in the foster home among youth placed alone with a history of sibling placements. Unexpectedly, youth placed alone, either throughout their stay in foster care or after a history of sibling placements, were less likely to exit to adoption or subsidized guardianship than youth with consistent joint sibling placements.
Involvement of coated vesicles in the initiation of fast axonal transport

The present study examines whether coated vesicles play a role in the intrasomal transit of newly synthesized fast-transported proteins. Coated vesicles isolated from bullfrog brain were shown to have a protein composition and ultrastructure similar to purified bovine brain coated vesicles. Bullfrog brain was then used as unlabeled carrier for the isolation of coated vesicles from dorsal root ganglia labeled with [3H]leucine. Fast-transported [35S]methionine-labeled proteins were generated in separate preparations from sciatic nerve, and co-electrophoresed on two-dimensional gels with [3H]proteins of the coated vesicle fraction. The [35S]Met fluorographic X-ray film pattern was used as a guide to remove gel regions which were tested for the presence of 3H. By this means, 45 of 67 individual fast-transported proteins examined were found to contain significant levels of 3H. The fact that these proteins have similar net charge and molecular weight characteristics to the mature fast-transported proteins with which they co-migrated, suggests that such species have already undergone post-translational modifications prior to becoming associated with coated vesicles. Since most modifications of this type occur in the Golgi apparatus, it appears that the majority of fast-transported proteins are isolated in association with a population of post-Golgi coated vesicles. The role of coated vesicles is incorporated into a model describing the pathway taken by fast-transported proteins during the initiation of fast axonal transport.
A Stroke of Insight

For years, intravenous tissue plasminogen activator (t-PA) has been the only effective acute stroke therapy. However, the treatment landscape for acute ischemic stroke has evolved rapidly in the past decade. With the advent of neuroendovascular therapies, large vessel strokes are now being treated