cssi/SciSciGPT-SciSciNet huggingface dataset:
Experimental modulation of PRPP availability for ribonucleotide synthesis from hypoxanthine in human skin febroblast cultures

Abstract The intracellular concentration of the cosubstrate 5-phosphoribosyl 1-pyrophosphate (PRPP) may be rate-limiting for the reactions, catalysed by hypoxanthine phosphoribosyltransferase, by which mammalian cells convert the purine bases hypoxanthine, xanthine, and guanine to their ribonucleotide derivatives. The rate of conversion of [14C]hypoxanthine to radioactive phosphorylated products by intact human diploid skin fibroblasts was measured in the presence of compounds previously reported to alter PRPP concentration in a variety of cell types Methylene blue, previously reported to increase PRPP concentration in a variety of cultured cells including skin fibroblasts, increased product formation from hypoxanthine, with maximum effect following 60 min preincubation with 0.4 mM. Incubation with adenine, orotic acid, allopurinol, or adenosine has been shown to decrease PRPP concentration. Of these compounds, only adenine and adenosine decreased the rate of ribonucleotide synthesis from hypoxanthine in cultured skin fibroblasts. This decrease probably resulted from decreased PRPP synthesis rather than increased PRPP utilization. The reaction products isolated from cells following incubation with either [14C]adenine or [14C]adenosine included adenosine monophosphate and adenosine diphosphate, both inhibitors of PRPP synthetase.
The Construct and Concurrent Validity of the Social Dimension of the Brown Locus of Control Scale

This paper presents data regarding the reliability and validity of a new locus of control scale. In addition to items measuring internality and powerful others externality, the scale has a conceptually new dimension referred to as external social.
Degradation of yeast cytochromes c dependent and independent on its physiological partners.

Altered iso-1- and iso-2-cytochromes c, with certain amino acid replacements, occur at diminished levels due to degradation in the yeast Saccharomyces cerevisiae. A subclass of the labile isocytochromes c are significantly protected from degradation by the presence of cytochromes a.a3 and c1, the physiological partners of cytochrome c. We have investigated the degradation that is dependent on physiological partners by examining the levels of iso-1-cytochrome c having all or most amino acid replacements at positions 6, 41, 52, and 78, in both rho+ strains and rho- strains, which lacks cytochrome a.a3. In addition, we have examined some of these replacements in strains also having the N52I replacement, which suppresses a variety of abnormal iso-1-cytochromes c, including those whose degradation is either dependent or independent on the physiological partners. Although some degree of preferential rho--dependent reductions was observed for iso-1-cytochromes c having replacements at each of the 6, 41, 52, and 78 sites, prominent effects of rho+/rho- ratios of approximately 100/0 to 30/0 were observed for iso-1-cytochromes c having replacements mainly at the 41, 52, and 78 sites, but not the G6 site. We suggest that prominent degradation dependent on physiological partners may be restricted to certain regions of the cytochrome c molecule. Furthermore, we suggest that the region of the largest confirmational difference between oxidized and reduced cytochrome c appears to be particularly protected by interactions with its physiological partners.
Ileocaecocystoplasty in urinary tract reconstruction in children.

Summary— Ten children have undergone lower urinary tract reconstruction by ileocaecocystoplasty. Four patients had previously been diverted and the other six were reconstructed because of intractable incontinence or deteriorating renal function. Continence was primarily achieved in eight patients and renal function improved or remained stable in all 10. Reflux was prevented by a plicated ileocaecal valve in five of eight patients. Continued pharmacological manipulation, intermittent self catheterisation and secondary surgical intervention were frequently necessary in these patients who required careful counselling and follow-up.
“Engulfed in a Whirlwind”: Diaghilev’s Dancers in the Postwar Ballets Russes

Abstract During Worl War I and the postwar period, the Ballets Russes bacame a truly international company, forced to absorb and adapt to the very latest trends in contemporary Western culture. This article describes the challenges facing dancers in the post-war period.
Uptake of calcium phosphate nanoshells by osteoblasts and their effect on growth and differentiation.

The influence of calcium phosphate nanoshell materials on the uptake, viability, and mineralization of human fetal osteoblast cultures was evaluated. Proliferation rates and alkaline phosphatase activity of the cultures were unaffected by the addition of nanoshells to the growth media, but mineralization levels were enhanced by nearly 40%, in contrast to media prepared without nanoshells, or with other calcium phosphate nanomaterials. Nanoshells were internalized by macropinocytosis, and migrated toward the cell nucleus at a rate of 0.34 μm hr−1. Dye-loaded nanoshells maintained high light emission intensity for over five days while inside the cells, where they could be used as intracellular markers for in vitro microscopic imaging. From these results, it appears that the CaP nanoshells could be developed into a safe sensor and delivery vehicle for osteoblast cell culture studies, whereas the carrier itself has intrinsic bioactivity and may itself upregulate the formation of new bone. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Restoring pristine Bi2Se3 surfaces with an effective Se decapping process

High quality thin films of topological insulators (TI) such as Bi2Se3 have been successfully synthesized by molecular beam epitaxy (MBE). Although the surface of MBE films can be protected by capping with inert materials such as amorphous Se, restoring an atomically clean pristine surface after decapping has never been demonstrated, which prevents in-depth investigations of the intrinsic properties of TI thin films with ex situ tools. Using high resolution scanning tunneling microscopy/spectroscopy (STM/STS), we demonstrate a simple and highly reproducible Se decapping method that allows recovery of the pristine surface of extremely high quality Bi2Se3 thin films grown and capped with Se in a separate MBE system then exposed to the atmosphere during transfer into the STM system. The crucial step of our decapping process is the removal of the surface contaminants on top of amorphous Se before thermal desorption of Se at a mild temperature (∼210 °C). This effective Se decapping process opens up the possibility of ex situ characterizations of pristine surfaces of interesting selenide materials and beyond using cutting-edge techniques.
Generation of protective immunity against an immunogenic carcinoma requires CD40/CD40L and B7/CD28 interactions but not CD4(+) T cells.

Interactions between CD40 and CD40L play a central role in the regulation of both humoral and cellular immunity. Recently, interactions between these molecules have also been implicated in the generation of protective cell-mediated tumor immunity. We have generated a tumor model in which a well-understood and clearly immunostimulatory antigen, influenza hemagglutinin has been transfected into the BALB/c-derived, MHC-class-I-positive, B7-deficient murine mammary carcinoma, MT901. In this model, expression of the influenza hemagglutinin antigen does not alter tumorigenicity in naive but serves as a tumor-rejection target in immunized mice. T-cell-depletion experiments indicate that successful tumor protection can occur following immunization in mice depleted of CD4+ but not CD8+ T cells, suggesting that tumor protection is largely CD8-mediated and CD4-independent. Interestingly, despite the ability of tumor protection to be generated in the absence of CD4+ T cells, effective immunization was clearly dependent on CD40/CD40L as well as CD28/B7 interactions.
DARPA, SDI, and GaAs

When silicon replaced germanium in the early 1960's as the semiconductor of choice for solid state devices, it converted the entire industry in just a few years because of two important characteristics. First, silicon has a higher energy bandgap, which permits silicon-based devices to operate over a wider temperature range (a feature especially important to the military). Second, and more important, silicon has a native oxide that provided for improved stability and planar, rather than mesa, type devices. Planar technology soon spawned integrated circuits. The integrated circuit in turn brought on the electronics revolution, allowing the complexity of circuits to increase by a factor of two every year (Moore's Law) and bringing us from single transistors to megabit memory chips.
Hepatitis C patients’ self‐reported adherence to treatment with pegylated interferon and ribavirin

Aliment Pharmacol Ther 28, 289–293 Summary Background Prior research on adherence to hepatitis C treatment has documented rates of dose reductions and early treatment discontinuation, but little is known about patients’ dose-taking adherence. Aims To assess the prevalence of missed doses of pegylated interferon and ribavirin and examine the correlates of dose-taking adherence in clinic settings. Methods One hundred and eighty patients on treatment for hepatitis C (23% co-infected with HIV) completed a cross-sectional survey at the site of their hepatitis C care. Results Seven per cent of patients reported missing at least one injection of pegylated interferon in the last 4 weeks and 21% reported missing at least one dose of ribavirin in the last 7 days. Dose-taking adherence was not associated with HCV viral load. Conclusions Self-reported dose non-adherence to hepatitis C treatment occurs frequently. Further studies of dose non-adherence (assessed by method other than self-report) and its relationship to HCV virological outcome are warranted.
Taxonomic placement of Calycogonium squamulosum (Melastomataceae: Miconieae)

Calycogonium squamulosum Cogn., a Puerto Rican endemic, is shown properly to be placed inHenriettea DC, (includingHenriettella Naud.), and this transfer is made. The species is allied to several other lepidote taxa ofHenriettea, e.g.,H. squamata (Alain) Alain andH. acunae (Alain) Alain (all endemic to the Oriente region of Cuba).Calycogonium squamulosum is also compared to the Hispaniolan endemic,Henriettea barkeri (Urban & Ekman) Alain [syn.H. elliptica (Urban) Alain], a species with stellate to stellate-strigose hairs.
Long-term efficacy of orbital decompression for compressive optic neuropathy of Graves' eye disease.

Abstract In a retrospective evaluation of the long-term effect of transantralethmoidal decompression for compressive optic neuropathy, the authors evaluated visual acuity, visual fields, color vision, and motility in 30 patients (52 orbits) for a median follow-up period of 2.5 years (range, 0.6 to 6.5 years). Patients with preoperative visual acuity of 20/40 or better uniformly remained in this category and demonstrated an earlier stabilization of vision than those with poorer preoperative visual acuity. Of the ten patients whose preoperative visual acuity was 20/50 to 20/100, 80% attained acuity of 20/40 or better. In patients whose visual acuity was 20/200 or less (n = 7), 57% attained an acuity of 20/40 or better. The most common visual field defect was generalized constriction, which was noted in 43 of the 52 eyes (83%). After decompression, the preoperative visual field defect had improved or completely resolved in all but one case. Dyschromatopsia, noted in 20 eyes preoperatively, cleared in 17 (85%) postoperatively. Although the study showed that surgical decompression is beneficial, some patients may require additional modalities of treatment.
Variables Affecting Fracture Toughness of Welds in T-K-Y Connections

Fracture toughness of tubular welded joints is one of the critical factors affecting the structural integrity and reliability of offshore structures, such as platforms and subsea pipelines. The factors affecting the design fracture toughness of these structures are related to, both, the welding process as well as the chemical composition of the weld metal.The welding process in this application typically comprises of depositing weld metal in the tubular joints of varying thicknesses through series of weld passes. The number of weld passes required for welding these joints subjects the weld metal to repetitive cycles of heating and cooling. The effect of the thermal cycling introduces significant heterogeneity in the microstructure. This is further exacerbated by the presence of micro-alloying elements such as Niobium (Nb) and Vanadium (V) that form complex carbides, nitrides and carbo-nitrides during post weld heat treatment (PWHT).The focus of this work is to evaluate the effect of micro-alloying elements on the ductile to brittle transition temperature and the mode of fracture at temperatures relevant to offshore applications. A threshold Nb and V level has been determined for achieving acceptable weld metal toughness. The improvement in the fracture toughness using this approach has been quantified by Charpy V-Notch (CVN) and Crack Tip Opening Displacement (CTOD) measurements. The Ductile to Brittle Transition Temperature (DBTT) has been shown to be shifted to lower temperatures by 25 °C after post weld heat treatment in the welds where the total amount of Nb and V are controlled to less than 40 ppm.A wet precipitate extraction technique was used to extract precipitates from the welds to establish the presence of fine Nb rich precipitates in the welds with the higher DBTT. The weld deposited with controlled levels of Nb and V was further tested in different joint configurations and base plate thickness. The fracture toughness was evaluated by CTOD testing of the weld in two different thicknesses (50 mm and 70 mm). Increased specimen thickness resulted in lower CTOD values.Copyright © 2014 by ASME
Digital image analysis of coating defects

Abstract A simple, low cost, easy to use computer-based Digital Image system has been developed for characterizing defects which occur in various types of organic films. The system uses an optical microscope, high resolution TV camera, frame grabber to display the image on Macintosh computer and software to analyze and characterize the image. All components are commercially available. Using this system, many different defects which are typically seen in organic coatings and the support on to which they are coated, such as spots, bubbles, reticulation streaks and pinholes can be rapidly characterized. Quantitative information about the defect, such as size and frequency can be rapidly obtained to assist in determining the cause. Images obtained of the defects can also be enhanced to obtain characterization information not easily seen in the defect. The system has applications in the R and D laboratory for understanding defect mechanisms, in trouble-shooting plant and end-use problems and in the control laboratory. It can also be used to provide routine quantitative testing information on defects that have been typically evaluated by subjective tests and comparison with go/no-go standards. The system is easier to use than viewing with a glass or conventional microscope and a permanent record of the defects can easily be stored and retrieved in a computer database to assist in troubleshooting.
Theoretical examination of destination loyalty formation

Purpose – The purpose of this paper is to identify the most critical antecedents of destination loyalty formation (DLF) and to develop a series of propositions for the relationships among the antecedents of loyalty formation and their direct and indirect impacts on loyalty formation. Design/methodology/approach – This conceptual paper provides a comprehensive review of the previous studies that examined destination loyalty and posits a framework of tourist DLF titled Destination Loyalty Formation. Findings – In the proposed conceptual model, the sequential relationships among the antecedents of tourist destination loyalty postulate that previous experiences are the most influential driver that could manipulate tourist destination loyalty. Place attachment and involvement constitute the second most influential factors of DLF. In addition to the above two variables, destination image is proposed to have direct and indirect effects on perception of service quality and satisfaction. Meanwhile, service quality...
Sodium Channel Subtypes in the Rat Display Functional Differences in the Presence of Veratridine

The alkaloid neurotoxin veratridine has the unique property of functionally distinguishing sodium channel subtypes in the rat through differences in single channel conductances, channel substates and probability of channel opening. Veratridine-activated cardiac sodium channels from rat ventricular muscle displayed a single channel conductance of 8.4 pS with no evidence of subconductance states or channel subtypes. Rat skeletal muscle sodium channels displayed both high (8.5 pS) and low conductance (4.7 pS) openings as well as a lower probability of opening (approximately 50%) at depolarized potentials than shown with brain or cardiac sodium channels (90-95%). Rat brain veratridine-activated sodium channels displayed primarily subconductance states at depolarized potentials (3-6 pS) and full conductance of approximately 9.5 pS at hyperpolarized potentials.
Optimisation of frequencies of a two-span shaft system joined with a hinge

A driveshaft with discontinuities (i.e. joints) is a major component in various industries. A multi-piece driveshaft in automotive applications is joined using constant velocity or universal joints or a combination of both. This article presents an exact solution for the vibration of a two-piece driveshaft with an intermediate single joint. The joint is modelled as a frictionless internal hinge. The Euler-Bernoulli beam theory is used. Lumped masses are placed on each side of the joint to represent the joint mass. Equations of motion are developed using the appropriate boundary conditions and then solved using exact solutions. Natural frequencies and modes shapes are obtained. Numerical results obtained here are compared with those obtained using experimental and analytical tools (e.g. finite elements). Parametric studies are performed and optimisation studies are conducted to maximise bending frequencies. Effects of many parameters are examined.
Inactivation of methicillin, oxacillin and ancillin by Staphylococcus aureus.

SummaryEach of the 3 semisynthetic penicillins–ancillin, methicillin and oxacillin–was studied for inactivation by a penicillinase-producing strain of Staphylococcus aureus. Starting with 108 viable staphylococcal units per ml and a concentration of each penicillin 15 times the minimum inhibiting (and bactericidal) concentration (MIC) for 105 organisms per ml in the same medium, these penicillins were inactivated at 37°C at a much more rapid rate than in the same medium at the same temperature without organism, or with the same number of organisms at 4°C,† or in a non-nutrient medium† (buffer, pH 6.4) at 37°C. The inactivation of each of these penicillins was accompanied first by a steady fall in the number of viable staphylococci until the concentration of drug fell below the “usual MIC,' after which there was demonstrable multiplication of the organisms. The organisms that survived and multiplied were no less susceptible than the parent strain to the action of the penicillin to which they had been exposed.
Lipreading in School-Age Children: The Roles of Age, Hearing Status, and Cognitive Ability.

Purpose The study addressed three research questions: Does lipreading improve between the ages of 7 and 14 years? Does hearing loss affect the development of lipreading? How do individual differences in lipreading relate to other abilities? Method Forty children with normal hearing (NH) and 24 with hearing loss (HL) were tested using 4 lipreading instruments plus measures of perceptual, cognitive, and linguistic abilities. Results For both groups, lipreading performance improved with age on all 4 measures of lipreading, with the HL group performing better than the NH group. Scores from the 4 measures loaded strongly on a single principal component. Only age, hearing status, and visuospatial working memory were significant predictors of lipreading performance. Conclusions Results showed that children's lipreading ability is not fixed but rather improves between 7 and 14 years of age. The finding that children with HL lipread better than those with NH suggests experience plays an important role in the devel...
Association of pre-pregnancy BMI and postpartum weight retention with postpartum HbA1c among women with Type 1 diabetes.

Aim To examine the association of pre-pregnancy BMI and postpartum weight retention with postpartum HbA1c levels in women with Type 1 diabetes. Methods We longitudinally evaluated 136 women with Type 1 diabetes who received prenatal, pregnancy, and postpartum care through Joslin Diabetes Center's Diabetes and Pregnancy Program between 2004 and 2009. Weight, BMI and HbA1c concentrations were assessed before the index pregnancy and repeatedly monitored after delivery until 12 months postpartum. We used linear mixed models to assess the association of postpartum HbA1c with pre-pregnancy BMI and postpartum weight retention. Results The mean HbA1c concentration increased from 49 mmol/mol (6.6%) at 6 weeks postpartum to 58 mmol/mol (7.5%) by 10 months postpartum, a level similar to the mean pre-pregnancy HbA1c concentration. Postpartum weight retention showed a linearly decreasing trend of 0.06 kg/week (P < 0.0001), with −0.1 kg average postpartum weight retention by 1 year postpartum. Compared with women with a pre-pregnancy BMI ≥ 25 kg/m2, women with a lower pre-pregnancy BMI maintained a 3.4 mmol/mol (0.31%) lower HbA1c concentration, after adjusting for several sociodemographic, reproductive and diabetes-related factors (P = 0.03). There was a suggestion of a time-varying positive association between HbA1c and postpartum weight retention, with the most significant difference of 3.7 mmol/mol (0.34%; P = 0.05) at 30 weeks postpartum among women with postpartum weight retention ≥ 5 kg vs those with postpartum weight retention < 5 kg. Conclusions Pre-pregnancy BMI and postpartum weight retention were positively associated with HbA1c during the first postpartum year in women with Type 1 diabetes. Interventions to modify the behaviours associated with these body weight factors before pregnancy and after delivery may help women with Type 1 diabetes maintain good glycaemic control after pregnancy.
H. saimiri tyrosine-kinase interacting protein inhibits Tat function: A prototypic strategy for restricting HIV-1-induced cytopathic effects in immune cells

Abstract Herpesvirus saimiri (HVS)-transformed human T cells become permissive for X4 and R5 strains of human immunodeficiency virus type 1 (HIV-1), evidence that HVS-encoded proteins associated with T cell transformation enhance HIV-1 replication. Analyzing the contribution of transformation-associated bicistronic HVS open reading frames (ORF) to HIV-1 replication revealed expression of the second ORF saimiri transformation-associated protein type C (StpC) conferred the permissive phenotype to T cells. In contrast, expression of the first HVS ORF tyrosine-kinase interacting protein (Tip) in the absence of StpC enhanced restriction of HIV-1 replication in T cell lines and peripheral blood mononuclear cells. Understanding the mechanism whereby Tip enhanced restriction of HIV-1 replication may uncover unique pathways that could be targeted therapeutically. Here we report that Tip restricts HIV-1 replication in a monocyte-derived cell line and restricts reactivation of replication of HIV-1 in a T cell line harboring provirus. In this report, we begin to unravel the molecular underpinnings of Tip-mediated restriction. Tip mediates both lymphocyte-cell-specific kinase (Lck)-dependent and -independent effects on HIV-1 replication. We also provide evidence that Tip-mediated restriction is in part due to inhibition of Tat transactivation of the HIV-1 long terminal repeat (LTR). Expression of Tip in T cells increased activation of Stat1 and Stat3, as well as activation of protein kinase RNA-dependent (PKR/p68) and interferon-γ production. Taken together, these results provide evidence that Tip restricts HIV-1 replication and reactivation by inhibiting HIV-1 transcription while inducing an intercellular antiviral state. We propose that genetically engineered vectors driving Tip expression could provide a prototypic strategy for restricting HIV-1 replication and reactivation in diverse cell lineages.
Myxoma virus combined with rapamycin treatment enhances adoptive T cell therapy for murine melanoma brain tumors

Adoptive transfer of tumor-specific T cells has shown some success for treating metastatic melanoma. We evaluated a novel strategy to improve adoptive therapy by administering both T cells and oncolytic myxoma virus to mice with syngeneic B16.SIY melanoma brain tumors. Adoptive transfer of activated CD8+ 2C T cells that recognize SIY peptide doubled survival time, but SIY-negative tumors recurred. Myxoma virus killed B16.SIY cells in vitro, and intratumoral injection of virus led to selective and transient infection of the tumor. Virus treatment recruited innate immune cells to the tumor and induced IFNβ production in the brain, resulting in limited oncolytic effects in vivo. To counter this, we evaluated the safety and efficacy of co-administering 2C T cells, myxoma virus, and either rapamycin or neutralizing antibodies against IFNβ. Mice that received either triple combination therapy survived significantly longer with no apparent side effects, but eventually relapsed. Importantly, rapamycin treatment did not impair T cell-mediated tumor destruction, supporting the feasibility of combining adoptive immunotherapy and rapamycin-enhanced virotherapy. Myxoma virus may be a useful vector for transient delivery of therapeutic genes to a tumor to enhance T cell responses.
Labor Migration Amongst Hierarchically Competing and Intervening Origins and Destinations

A spatial interaction methodology is developed for modeling flows in a hierarchical system. A competing and intervening destinations framework is employed to model and predict US state-to-state labor migration. This analysis is used to assess the importance of geographic variables in explaining variations in regional labor flows. Empirical findings suggest that US labor migration is largely explained by Newtonian and systemic forces—size, distance, locational accessibility, and intervening opportunities in a spatial hierarchy. It is also suggested that lagged migration or migrant stock is a product of the combined effect of these forces.
Particle swarm optimization-based parameter identification applied to permanent magnet synchronous motors

The high-performance application of high-power permanent magnet synchronous motors (PMSM) is increasing. PMSM models with accurate parameters are significant for precise control system designs. Acquisition of these parameters during motor operation is a challenging task due to the inherent nonlinearity of motor dynamics. This paper proposes an intelligent model parameter identification method using particle swarm optimization (PSO). PSO, an intelligent computational method based on stochastic search, is shown to be a versatile and efficient tool for this complicated engineering problem. Through both simulation and experiment, this paper verifies the effectiveness of the proposed method in identification of PMSM model parameters. Specifically, stator resistance and load torque disturbance are identified in this PMSM application. Though PMSM is presented, the method is generally applicable to other types of electrical motors, as well as other dynamic systems with nonlinear model structure.
Preservation and Self-Absorption: Italian Colonisation and the Walled City of Tripoli, Libya

Scholars periodically return to the study of how French administrators and architects handled urban settings in North Africa, beginning with the occupation of Algiers in 1830. Italian occupation of Libya began much later, in 1911, but in the thirty-two years of their effective rule, Italians also had sufficient time to be both destructive and constructive in significant ways. In this chapter, I discuss attitudes to the walled city of Tripoli on the part of military personnel, government bureaucrats, and planners—the people who decided how to reshape Tripoli, and whose voices fill the documents in the archives of the colonial administration. In these policies, I read what looks like Italian actions leading to the relative preservation of Tripoli’s walled city as a series of planning choices that were, in reality, more passive than active. There was no detailed program to preserve old Tripoli, but decisions were made to shore it up just enough so that the city would require the least attention and investment possible. The Italian treatment of Tripoli’s walled city is thus a negative instance of preservation policy, or a case of preservation by default.
What can dynamic therapies contribute to behavior therapy

The present paper approaches the question in the title in two ways. First, it shows how behavior therapists' attitudes toward psychoanalysis may be based on unfamiliarity with modern developments in psychoanalytic throught that correct some of the features to which they most object. Second, the paper illustrates how the use of psychodynamic concepts can aid the behavior therapist in dealing with commonly encountered clinical difficulties. Clinical examples both amplify the specific clinical use of psychodynamic concepts in a behavioral context and illustrate how evidence for such notions can be obtained from the phenomena observed in clinical work.
Characterization of sealed radioactive sources: uncertainty analysis to improve detection methods

A radioactive 137Cs source has been analyzed for the radioactive parent 137Cs and stable decay daughter 137Ba. The ratio of the daughter to parent atoms is used to estimate the date when Cs was purified prior to source encapsulation (an “age” since purification). The isotopes were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) after chemical separation. In addition, Ba was analyzed by isotope dilution ICP-MS (ID-ICP-MS). A detailed error analysis of the mass spectrometric work has been undertaken to identify areas of improvement, as well as quantifying the effect the errors have on the “age” determined. This paper reports an uncertainty analysis to identifying areas of improvement and alternative techniques that may reduce the uncertainties. In particular, work on isotope dilution using ICP-MS for the “age” determination of sealed sources is presented. The results will be compared to the original work done using external standards to calibrate the ICP-MS instrument.
A novel micro glow plug fabricated from polymer-derived ceramics: in situ measurement of high-temperature properties and application to ultrahigh-temperature ignition

Abstract This work describes the design, fabrication, modeling, characterization and testing of a new class of MEMS: micro igniters for ultrahigh-temperature (exceeding 1000 °C) ignition applications. Micro glow plugs (MGPs) were fabricated from polymer-derived silicon carbon–nitride (SiCN), which is a recently-developed and highly refractory ceramic derived from a liquid polymer precursor. SiCN has been shown to possess outstanding mechanical robustness, corrosion resistance, and thermal shock resistance at ultrahigh-temperatures, making it an ideal material for harsh environment applications. The micro glow plug achieved temperatures of up to 1450 °C, with a response time of
Murine models of susceptibility to tuberculosis.

Summary Approximately one third of the world’s population is infected with Mycobacterum tuberculosis, yet each year a small proportion of those individuals progress to an active disease state. Early identification and treatment of such individuals is essential to reduce transmission; however, genetic and immunological correlates of disease progression have not been well established in man. The murine model has been a central tool for the elucidation of protective immune mechanisms that are essential for controlling M. tuberculosis infection. Additionally, the study of inbred mice has revealed significant divergence in the susceptibility and disease progression of individual mouse strains to an infection with M. tuberculosis. The continued study of genetically disparate mouse strains has the potential to identify immune mechanisms that correlate with increasing susceptibility to tuberculosis. These mechanisms will be highly applicable to studies in man and assist in the early detection of individuals that are more vulnerable to the development of reactivation tuberculosis.
Regulation of α-Smooth Muscle Actin Expression in Granulation Tissue Myofibroblasts Is Dependent on the Intronic CArG Element and the Transforming Growth Factor-β1 Control Element

Myofibroblasts are specialized contractile fibroblasts that are critical in wound closure and tissue contracture. Generation of contractile force is correlated with the expression of α-smooth muscle actin (α-SMA); however, little is known regarding molecular mechanisms that control activation of α-SMA in myofibroblasts in granulation tissue. The aims of the present studies were to identify sufficient promoter regions required for α-SMA expression in myofibroblasts in vivo and to determine whether activation of α-SMA expression in myofibroblasts in vivo is dependent on an intronic CArG [CC(A/T)6GG] and a transforming growth factor-β1 control element (TCE) that are required for α-SMA expression in smooth muscle cells. A Lac Z transgene construct from −2600 through the first intron was expressed in myofibroblasts within granulation tissue of cutaneous wounds in a pattern that closely mimicked endogenous α-SMA expression. Mutation of either the intronic CArG element or the TCE completely inhibited transgene expression in myofibroblasts in granulation tissue and responsiveness to transforming growth factor-β1 in cultured transgenic fibroblasts. These same elements were also critical in regulating α-SMA expression during skeletal muscle repair but not during skeletal muscle development. Taken together, these results provide the first in vivo evidence for the importance of the intronic CArG and TCE cis-elements in the regulation of α-SMA expression in myofibroblasts in granulation tissue.
Characteristics of normal corneal topography using the EyeSys corneal analysis system

Abstract Purpose: To study the parameters of corneal topography of normal eyes using the Corneal Analysis System (CAS, EyeSys Technologies) to determine the types and frequency of patterns and parameters. Setting: University of Illinois Eye Center, Chicago, Illinois, USA. Methods: Three independent, masked judges, using a forced-choice paradigm, classified corneal topography patterns into six categories on one randomly selected, normal eye of 100 persons who did not wear contact lenses. The patterns were defined by using the midpoint dioptric bin and a 0.50 diopter (D) steeper bin. Results: The pattern frequency using the mid-dioptric bin was teardrop (6%), amorphous (11%), round (11%), symmetric bow tie (17%), asymmetric bow tie (1%), kidney (22%), and oval (32%). Mean refractive and keratometric cylinders, respectively, were teardrop (0.13 and 0.15 D), amorphous (0.15 and 0.49 D), round (0.18 and 0.56 D), oval (0.21 and 0.56 D), kidney (0.51 and 0.72 D), and bow tie (1.18 and 1.82 D). Pattern frequency using the 0.50 D steeper bin was round (2%), oval (5%), teardrop (6%), kidney (15%), amorphous (17%), asymmetric bow tie (17%), and symmetric bow tie (37%). Mean refractive and keratometric cylinders, respectively, were round (0.13 and 0.32 D), amorphous (0.25 and 0.38 D), kidney ' (0.11 and 0.42 D), oval (0.40 and 0.59 D), teardrop (0.08 and 0.75 D), and bow tie (0.65 and 1.09 D). Mean flat and steep contours were 41.76 D (95% confidence interval [CI], 38.68 to 44.84 D) and 44.15 D (95% CI, 41.00 to 47.31 D), respectively. Mean contour range was 2.40 D (95% CI, 0.61 to 4.17 D). Conclusion: The data suggest that for 95% of normal corneas, corneal contours will be steeper than 38.50 D, flatter than 47.50 D, and have a contour range less than 4.25 D when using the EyeSys CAS.
CTCF binding sites promote transcription initiation and prevent DNA methylation on the maternal allele at the imprinted H19/Igf2 locus

Imprinting at the H19/Igf2 locus depends on a differentially methylated domain (DMD) acting as a maternal-specific, methylation-sensitive insulator and a paternal-specific locus of hypermethylation. Four repeats in the DMD bind CTCF on the maternal allele and have been proposed to recruit methylation on the paternal allele. We deleted the four repeats and assayed the effects of the mutation at the endogenous locus. The H19DMD-DeltaR allele can successfully acquire methylation during spermatogenesis and silence paternal H19, indicating that these paternal-specific functions are independent of the CTCF binding sites. Maternal inheritance of the mutations leads to biallelic Igf2 expression, consistent with the loss of a functional insulator. Additionally, we uncovered two previously undescribed roles for the CTCF binding sites. On the mutant allele, H19 RNA is barely detectable in 6.5 d.p.c. embryos and 9.5 d.p.c. placenta, for the first time identifying the repeats as the elements responsible for initiating H19 transcription. Furthermore, methylation is abruptly acquired on the mutant maternal allele after implantation, a time when the embryo is undergoing genome-wide de novo methylation. Together, these experiments show that in addition to being essential for a functional insulator, the CTCF repeats facilitate initiation of H19 expression in the early embryo and are required to maintain the hypomethylated state of the entire DMD.
Diffusion in the laminar boundary layer with a variable density

The problem of isothermal diffusion in a variable molecular-weight binary gas mixture is considered for the case when the process occurs in a laminar boundary layer. Viscosity and diffusion coefficient are assumed constant. Solutions are given for both forced and free convection at large Schmidt numbers and large mass transfer rates toward the surface. Use of the molar average velocity considerably simplifies the results. These results suggest that the constant density solution in terms of mole fractions, evaluated at free stream conditions, may be a good approximation for variable density. This technique, improved by an approximate correction derived herein, is shown to agree reasonably well with the results of exact numerical solutions of the boundary layer equations.
A modification of the POSSUM surgical audit system for the minimally invasive therapy community

SummaryThe POSSUM system has the potential to be the universally accepted basic surgical audit system. Some modifications are suggested to enhance POSSUM'S sensitivity.
Continuous non-invasive cardiac output measurements in the neonate by electrical velocimetry: a comparison with echocardiography

Objective Electrical velocimetry (EV) is a noninvasive method of continuous left cardiac output monitoring based on measurement of thoracic electrical bioimpedance. The objective was to validate EV by investigating the agreement in cardiac output measurements performed by EV and echocardiography. Design In this prospective observational study, left ventricular output (LVO) was simultaneously measured by EV (LVO ev ) using Aesculon and by echocardiography (LVO echo ) in healthy term neonates during the fi rst 2 postnatal days. To determine the agreement between the two methods, we calculated the bias (mean difference) and precision (1.96◊SD of the difference). As LVO echo has its own limitations, the authors also calculated the ‘true precision’ of EV adjusted for echocardiography as the reference method. Results The authors performed 115 paired measurements in 20 neonates. LVO ev and LVO echo were similar (534±105 vs 538±105 ml/min, p=0.7). The bias and precision of EV were 4 and 234 ml/min, respectively. The authors found the true precision of EV to be similar to the precision of echocardiography (31.6% vs 30%, respectively). There was no difference in bias and precision between the measurements obtained in patients with or without a haemodynamically signifi cant patent ductus arteriosus. Conclusions EV is as accurate in measuring LVO as echocardiography and the variation in the agreement between EV and echocardiography among the individual subjects refl ects the limitations of both techniques.
Hydrocortisone activation of human herpesvirus 8 viral DNA replication and gene expression in vitro.

Background. Patients undergoing chronic steroid therapy for organ transplantation are at increased risk for development of human herpes virus 8(HHV-8)-associated Kaposi's sarcoma (KS). It has also been reported that following steroid withdrawal, KS lesions often undergo partial or complete regression. Methods. We have examined the effect of corticosteroid treatment on HHV-8 replication, gene expression, and lytic protein expression in BCBL-1 cells in vitro. BCBL-1 cells were collected after culture for 24-72 hr with hydrocortisone (HC) 1-5 μM, phorbol ester 20 ng/ml (positive control), and culture medium only (negative control). HHV-8 genomic conformation was examined by Gardella gel analysis, mRNA expression of viral cyclin (v-Cyc), viral Bcl-2 (v-Bcl-2), viral macrophage inflammatory protein-I (v-MIP-I), viral interferon regulatory factor-1(v-IRF-1), and viral tegument protein (TP) was examined by RT-PCR Southern blot. Viral protein expression within the cells was examined by indirect immunofluorescence using 5 different HHV-8 positive antisera from 4 renal transplant recipients and 1 patient with classic KS. Results. Gardella gel analysis revealed that HC induced an accumulation of the linear replicative genomic form of the virus in a time-dependent fashion. Southern blot analysis of the RT-PCR products revealed that HC induced increased expression of v-IRF-1, v-Bcl-2, and TP mRNA, with little discernible effect on v-Cyc, and v-MIP-I. Immunofluorescence revealed that HC induced increased numbers of cells expressing lytic antigens. Conclusions. These data indicate that hydrocortisone acts directly on BCBL-1 cells to activate the lytic cycle of HHV-8 and provide further support for the hypothesis that HHV-8 is activated in corticosteroid-treated immunocompromised patients.
The Reconstruction of Failure: Ideologies of Educational Failure in Their Relation to Social Mobility and Social Control

This paper seeks to explain the use of ideologies concerning failure or non-failure in American education in terms of the struggle of sponsoring and professional groups to establish or maintain position on the social scene and, correspondingly, to gain control over those clienteles which are relevant to the particular drives for social or professional mobility. The author argues that the prevalence of theories that students should not fail is linked to the development of efforts for continuous control over such clienteles. However, she suggests that ultimately both the grounds on which such control is legitimated (especially ideologies of social mobility) and the reactions of students themselves may operate as constraints on the nature of the social control which it sought.
Demonstration of a high-resolution optical interrogation method for sampled fiber Bragg sensor

Fiber Bragg gratings are high-performance devices contained inside optical fibers for rapid and remote measurement of strain and temperature and, in certain setups, for reagentless and reusable chemical sensing. Existing interrogation methods for these fiber devices, however, require sensitive photonics components such as tunable lasers with moving parts that are not well suited for harsh environments, particularly under the vibration of mobile platforms. Presented here is an experimental proof of concept for a novel fiber grating interrogation method centered around the use of a compact, discretely-tunable, all-solid-state laser and a fiber Bragg superstructure device.
Comparison of selective retinoic acid receptor- and retinoic X receptor-mediated efficacy, tolerance, and survival in cutaneous t-cell lymphoma.

Primary cutaneous T-cell lymphomas are non-Hodgkin's lymphomas with varied clinical presentation and prognosis. The most common subtypes of cutaneous T-cell lymphomas are the epidermotropic variants mycosis fungoides and Sezary syndrome. Treatment of mycosis fungoides has encompassed a variety of modalities including the use of retinoids with several studies evaluating their efficacy. The reported benefits and duration of response have varied in published data. The biological effect of retinoids is mediated by specific receptor families, retinoic acid receptor (RAR) and retinoic X receptor (RXR), with subsequently altered gene expression. There are no data available on cutaneous T-cell lymphomas that compare RAR and RXR retinoids. The objective of our retrospective, nonrandomized, single-center study was to compare the response, survival outcomes, and toxic effects in our phase II trial of the RAR-specific retinoid, all-trans retinoic acid, with clinical use of the RXR-specific retinoid, bexarotene, in patients with mycosis fungoides/Sezary syndrome who have relapsed. There was no statistical difference in response rates (12% vs 21%), response duration (20.5 vs 7.3 months), event-free survival time (4 vs 5 months), or median survival when corrected for length of follow-up. Both have favorable toxicity profiles that can be managed with medications. The toxicity profile caused by bexarotene seems to be more limited to laboratory values and better tolerated, although generally associated with more severe grades of toxicity. In conclusion, both retinoids have modest objective response rates and, therefore, most likely will have limited impact as monotherapeutic agents. However, the immunomodulatory effects of RAR and RXR retinoids provide a rational basis for using retinoids in combination with other biologic immune response modifiers, phototherapy, or cytotoxic chemotherapy.
Time of supplemental feeding alters the effects of cocaine on lever pressing of rats

The present experiment assessed the effects of cocaine on the lever pressing of 4 rats maintained during 15-min sessions by a fixed-ratio 50 schedule of food reinforcement. Across phases, supplemental food was provided either immediately or 2 hr after sessions. Two rats began the experiment in the delayed-feeding condition, and 2 began the experiment in the immediate-feeding condition. Rates of lever pressing of 2 rats sometimes decreased to low levels near the ends of sessions when supplemental feeding was provided immediately, but were consistently high throughout sessions when supplemental feeding was delayed. Cocaine (1.0 to 17.0 or 30.0 mg/kg) was administered intraperitoneally 15 min prior to test sessions. In most cases, cocaine suppressed response rates at lower doses under immediate-feeding conditions. Decreases in overall response rates were correlated with dosedependent increases in the time rats spent not responding. It is suggested that delaying the time of postsession feeding increased response strength, as indicated by greater resistance to the rate-suppressive effects of cocaine.