cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystal Structure of Peroxide Stress Regulator from Streptococcus pyogenes Provides Functional Insights into the Mechanism of Oxidative Stress Sensing

Regulation of oxidative stress responses by the peroxide stress regulator (PerR) is critical for the in vivo fitness and virulence of group A Streptococcus. To elucidate the molecular mechanism of DNA binding, peroxide sensing, and gene regulation by PerR, we performed biochemical and structural characterization of PerR. Sequence-specific DNA binding by PerR does not require regulatory metal occupancy. However, metal binding promotes higher affinity PerR-DNA interactions. PerR metallated with iron directly senses peroxide stress and dissociates from operator sequences. The crystal structure revealed that PerR exists as a homodimer with two metal-binding sites per subunit as follows: a structural zinc site and a regulatory metal site that is occupied in the crystals by nickel. The regulatory metal-binding site in PerR involves a previously unobserved HXH motif located in its unique N-terminal extension. Mutational analysis of the regulatory site showed that the PerR metal ligands are involved in regulatory metal binding, and integrity of this site is critical for group A Streptococcus virulence. Interestingly, the metal-binding HXH motif is not present in the structurally characterized members of ferric uptake regulator (Fur) family but is fully conserved among PerR from the genus Streptococcus. Thus, it is likely that the PerR orthologs from streptococci share a common mechanism of metal binding, peroxide sensing, and gene regulation that is different from that of well characterized PerR from Bacillus subtilis. Together, our findings provide key insights into the peroxide sensing and regulation of the oxidative stress-adaptive responses by the streptococcal subfamily of PerR.
151. Day-to-day dynamics of associations between childhood adversity and cortisol diurnal rhythm in women diagnosed with breast cancer

A dysregulated cortisol diurnal rhythm is associated with a poorer prognosis for women with metastatic breast cancer. The purpose of this study was to investigate whether adversity experienced during childhood influences the dynamics of the cortisol rhythm in women newly diagnosed with early stage breast cancer. Women (N = 98) were evaluated after their diagnosis but before surgery. Women completed the Perceived Stress Scale and the Childhood Trauma Questionnaire to assess their levels of psychological stress and the degree of exposure to childhood adversity, respectively. Over two consecutive days, women collected saliva five times per day for cortisol measurement, while also completing sleep diaries to assess prior-night sleep quality, including nocturnal awakenings, and morning restfulness. Multilevel growth curve modeling was used to examine whether childhood adversity contributed to the day-to-day variations in the cortisol diurnal rhythm. Emotional and physical abuse were significant predictors of the cortisol quadratic slope, indicating that women who reported greater exposure to such childhood adversity had greater levels of cortisol at bedtime. These effects were independent of daily variation in prior-night sleep quality, perceived stress levels, as well as demographic and cancer disease factors. These findings demonstrate childhood adversity to be a preexisting risk factor for dysregulation of the cortisol diurnal rhythm in women experiencing the stress associated with breast cancer diagnosis. Such dysregulation may negatively impact cancer control.
Interval to testosterone recovery after hormonal therapy for prostate cancer and risk of death

Purpose To assess whether the risk of death is associated with the time to testosterone recovery (TTR) after radiotherapy (RT) and hormonal therapy (HT) for prostate cancer (PCa). Patients and Methods Between 1995 and 2001, 206 men with localized, unfavorable-risk PCa were randomized to receive RT or RT plus 6 months of HT. A multivariate postrandomization Cox regression analysis was used to assess whether the TTR in years was associated with the risk of death after adjusting for the known prognostic factors, age, Adult Comorbidity Evaluation-27 score, and the use of HT for recurrence. Results Of the 102 men randomized to receive RT and HT, 57 (56%) had a TTR of >2 years, and none of these men had died of PCa after a median follow-up of 7.6 years. As the TTR increased, the risk of death decreased significantly (adjusted hazard ratio, 0.60; 95% confidence interval, 0.43–0.84; p = .003). A significant interaction was noted between the TTR and the comorbidity score ( p = .002). The survival estimates were similar ( p = 0.17) across the TTR values in men with moderate to severe comorbidity; however, these estimates increased significantly ( p p = .006) as the TTR increased in men with no or minimal comorbidity. Conclusion The results of our study have shown that a longer TTR after RT plus 6 months of HT for unfavorable-risk PCa is associated with a lower risk of death in men with no or minimal comorbidity.
Validation of the Tufts Calcium Food Intake Frequency Questionnaire as a Measure of Calcium Intake in Men 65 Years of Age and Older

Abstract 84 healthy male outpatients were screened for a dietitian's interview during an osteoporosis prevention trial. Each participant had his dietary calcium separately analyzed using the HHHQ, Tufts and 3-Day food record. Demographic data were available in all 84 men, whereas dietary information was available for 82 subjects. Results: Mean value for subject age was 73±5.1yr.(mean±SD, range 65–88yr.), and that for body mass index (BMI) was 26.9 ±3.0kg/m2 (23.1-43). Average daily dietary calcium intake (mg/day) was 986±927 for the HHHQ (range 379–3904), 962±723 for Tufts (140–2712), and 948±711 for the 3-Day food record (213–1845). The average calcium intake using descriptive statistics for these three dietary intake forms were similar. Correlation Matrix revealed direct correlation's of Tufts with the HHHQ (0.523, p Conclusion: These data suggest that the Tufts Calcium Food Frequency Questionnaire is as reliable as the HHHQ and 3-Day Food Record in assessing daily Calcium intake in elderly men. Its advantage in being less time-consuming suggests that it will become a useful instrument in outpatient studies in men as well as in women.
Cytokinins in plant senescence: From spray and pray to clone and play

Three approaches have been used to investigate the inhibitory role of the cytokinin class of phytohormones in plant senescence: external application of cytokinins, measurement of endogenous cytokinin levels before and during senescence, and manipulation of endogenous cytokinin production in transgenic plants. In transgenic plant studies, endogenous cytokinin levels are manipulated by expression of IPT, a gene encoding isopentenyl transferase. Transgenic plants expressing IPT from a variety of promoters exhibit developmental and morphological alterations and often display retarded leaf senescence. A recently developed autoregulatory senescence-inhibition system targets cytokinin production quantitatively, spatially and temporally, and results in transgenic plants that exhibit significantly delayed senescence without abnormalities. These transgenic studies not only confirm the regulatory role of cytokinins in plant senescence, but also provide a way to manipulate senescence for potential agricultural applications.
Philanthropic partnerships and the future of cancer research.

Complementing government and industry funding, philanthropies have made distinct contributions to altering the trajectory of cancer research. This Science and Society article aims to investigate the changing role of philanthropy in fostering cancer research, with emphasis on the work of non-profit institutions.
Increased milk production versus reproductive and energy status of high producing dairy cows.

Abstract Two groups of 10 Holstein cows were chosen by pairs from a 20-yr genetic selection project that used either breed average or breed high sires chosen only for Predicted Differences in milk production. Milk production (305-d mature equivalent) was 10,814 kg and 6912 kg for the high and average groups of cows. Days to first visual estrus and number of ovulations before first visual estrus were greater for the high versus the average group (66 vs. 43 d and 1.6 vs. .7 ovulations). No differences were significant between groups for the interval from parturition to uterine involution or for days to first ovulation. Energy balance was less for the high group during wk 1, 2, 10, and 11. Plasma glucose concentration was lowest during wk 2 for both groups, and nonesterified fatty acids and β-hydroxybutyrate were greatest for both groups during wk 1 and 2. Liver glycogen content was lower at d 15 postpartum for the high group, and liver triglyceride content was greater on d 30 for the high group. The data for reproductive functions support the concept that high milk production is antagonistic to expression of estrous behavior but not to reactivation of ovarian function.
[2,2'-(2,6,9,13-Tetra-azatetra-decane-1,14-di-yl)diphenolato]iron(III) iodide.

The title FeIII complex, [Fe(C22H32N4O2)]I, contains a six-coordinate FeN4O2 cation in which the ligand is a reduced Schiff base resulting from the NaBH4 reduction of the condensation product between salicylaldehyde and 1,5,8,12-tetra­azadodecane. In spite of the increased flexibility of the saturated backbone of the ligand compared to the Schiff base from which it was synthesized, the complex adopts a cis-FeN4O2 conformation for the phenolic O-atom donors, which contrasts with the trans conformation adopted by the analogous ClO4− salt [Yisgedu et al. (2009). J. Chem. Crystallogr. 39, 315–319]. In addition to extensive N—H⋯I hydrogen bonding between the amine H atoms and the anion there is a weak C—H⋯I inter­action.
The infrared spectrum of thioformaldehyde

Abstract The infrared spectrum of thioformaldehyde (H 2 CS) has been observed in the CH stretching region. The spectrum was obtained under conditions of high resolution and rotational analyses have been carried out on the three observed bands. The main results (in cm −1 ) for the excited states are: Band ν 0 A B C ν 5 3024.61 9.675 0.5893 0.5554 ν 1 2971.03 9.648 0.5907 0.5542 2ν 6 (?) 2877.11 9.821 0.5936 0.5533 Several local perturbations have been observed in the two fundamentals ν 5 and ν 1 . These are presumably caused by overtones and combinations of the lower lying fundamentals but it has not been possible to make specific assignments of the perturbing levels.
An experimental determination of optimum processing parameters for Al/SiC metal matrix composites made using ultrasonic consolidation

Ultrasonic consolidation, an emerging additive manufacturing technology, is one of the most recent technologies considered for fabrication of metal matrix composites (MMCs). This study was performed to identify the optimum combination of processing parameters, including oscillation amplitude, welding speed, normal force, operating temperature, and fiber orientation, for manufacture of long-fiber-reinforced MMCs. A design of experiments approach (Taguchi L25 orthogonal array) was adopted to statistically determine the influences of individual process parameters. SiC fibers of 0.1 mm diameter were successfully embedded into an Al 3003 metal matrix. Push-out testing was employed to evaluate the bond strength between the fiber and the matrix. Data from push-out tests and microstructural studies were analyzed and an optimum combination of parameters was achieved. The effects of process parameters on bond formation and fiber/matrix bond strength are discussed.
Aspects of Organoselenium and Organotellurium Chemistry

The Chemistry of several condensed selenophenes, and tellurophenes (1–4) will be presented. The synthesis of mixed selenium-tellurium fulvenes (5) and generation of 2,4-bis-methyleneditelluretane (6) will be discussed.
On the model controversy for substrate-induced spin-state transition in cytochrome P450: (a new perspective).

Three models have been proposed for substrate-induced spin-state transition in cytochrome P450. These are referred to as two-three- and four-state models. In this communication the three models are reviewed with respect to their experimental basis and their ability to accommodate the results reported on the effects of substrates on spin-state and reduction of various P450′s. In addition, a new perspective is presented.
Antiemetics in children receiving cancer chemotherapy

Nausea and vomiting are debilitating side effects that often accompany the administration of chemotherapy and may lead to adverse physiological and psychological effects. Chemotherapy agents usually stimulate the chemoreceptor trigger zone, which then sends signals to the vomiting center in the medullary lateral reticular formation. The neurochemistry of vomiting involves serotonin and serotonin S3 receptors. Nausea and vomiting are difficult to treat once they have occurred, and prior poor antiemetic control may lead to future anticipatory nausea and vomiting. Thus, good antiemetic regimens must be prophylactic, scheduled, and individualized. Specific regimens must be adjusted to account for the emetogenic potential of the chemotherapy drug(s) being administered and the individual patient's preferences. The major classes of antiemetics include serotonin S3 receptor antagonists, phenothiazines and metoclopramide. Steroids are ineffective antiemetics alone but good potentiators of other antiemetics. We usually recommend a serotonin S3 receptor antagonist alone for less emetogenic regimens or in conjunction with dexamethasone for more emetogenic regimens. For breakthough vomiting, we usually add lorazepam and/or scopolamine.
Capacitation of bovine spermatozoa by lysophospholipids and trypsin.

Bovine spermatozoa were incubated in vitro with lysophosphatidylserine (LPS), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI), or trypsin. Capacitation of sperm was evaluated by penetration of the zonae pellucidae of dead bovine oocytes. Capacitation times could be shortened to 3 h or less by treatment of spermatozoa with each of these lysophospholipids (LPLs) (P less than .05). The maximum oocyte penetration percentages for individual LPLs were 40% for 10 microM LPS. 24% for 160 microM LPC, 31% for 320 microM LPE, and 19% for 320 microM LPI. Capacitation also was facilitated (P less than .01) by trypsin treatment of spermatozoa. Spermatozoa treated with 250 or 2,500 units/ml of trypsin penetrated more oocytes (17 and 18%) than spermatozoa treated with 0 or 25 units/ml of trypsin (0 and 3%). Spermatozoa treated with increasing concentrations of LPL showed a decrease in both the percentage of intact acrosomes and of progressively motile spermatozoa. Increasing levels of trypsin in the incubation medium also led to a decrease (P less than .05) in the percentages of intact acrosomes and a decrease (P less than .01) in the percentages of progressively motile spermatozoa. Percentages of live, ovulated oocytes fertilized by spermatozoa incubated for 1 h in LPS (86%, 6/7) were not different from those incubated for 24 h in control medium (71%, 5/7). Percentages of oocytes fertilized with both of these capacitation treatments were higher (P less than .05) than for oocytes exposed or killed or uncapacitated sperm. Rapid induction of capacitation and the acrosome reaction can be accomplished by exogenous treatment of bovine sperm with lysophospholipids or trypsin.
The Implications of the Nonlinear Paradigm for Integrated Environmental Design and Planning

The purpose of this article is to describe the potential implications of the "new sciences" such as chaos theory, self-organization theory, and complexity science to reconcile various different schools of philosophical thought in the environment development debate. Design, through the means of transdisciplinary analysis, here is conceived as a creative process that aids in the emergence of appropriate metaphors and models for the development of sophisticated environmental planning and policies. The epistemological and philosophical foundations of two broad paradigms of thought, the material and ecological paradigms, are examined to develop a more comprehensive approach to sustainable development. Surprisingly, this takes us into the terrain of Newtonian mechanics and principles of thermodynamics. The article then presents an alternative view of sustainability based on the emerging new science paradigm. Finally, the article examines some possible implicationsfor integrated environmental design and planning.
DNA-Linker-Induced Surface Assembly of Ultra Dense Parallel Single Walled Carbon Nanotube Arrays

Ultrathin film preparations of single-walled carbon nanotube (SWNT) allow economical utilization of nanotube properties in electronics applications. Recent advances have enabled production of micrometer scale SWNT transistors and sensors but scaling these devices down to the nanoscale, and improving the coupling of SWNTs to other nanoscale components, may require techniques that can generate a greater degree of nanoscale geometric order than has thus far been achieved. Here, we introduce linker-induced surface assembly, a new technique that uses small structured DNA linkers to assemble solution dispersed nanotubes into parallel arrays on charged surfaces. Parts of our linkers act as spacers to precisely control the internanotube separation distance down to <3 nm and can serve as scaffolds to position components such as proteins between adjacent parallel nanotubes. The resulting arrays can then be stamped onto other substrates. Our results demonstrate a new paradigm for the self-assembly of anisotropic colloidal nanomaterials into ordered structures and provide a potentially simple, low cost, and scalable route for preparation of exquisitely structured parallel SWNT films with applications in high-performance nanoscale switches, sensors, and meta-materials.
The regulation of ion channels and transporters by glycolytically derived ATP

Glycolysis is an evolutionary conserved metabolic pathway that provides small amounts of energy in the form of ATP when compared to other pathways such as oxidative phosphorylation or fatty acid oxidation. The ATP levels inside metabolically active cells are not constant and the local ATP level will depend on the site of production as well as the respective rates of ATP production, diffusion and consumption. Membrane ion transporters (pumps, exchangers and channels) are located at sites distal to the major sources of ATP formation (the mitochondria). We review evidence that the glycolytic complex is associated with membranes; both at the plasmalemma and with membranes of the endo/sarcoplasmic reticular network. We examine the evidence for the concept that many of the ion transporters are regulated preferentially by the glycolytic process. These include the Na+/K+-ATPase, the H+-ATPase, various types of Ca2+-ATPases, the Na+/H+ exchanger, the ATP-sensitive K+ channel, cation channels, Na+ channels, Ca2+ channels and other channels involved in intracellular Ca2+ homeostasis. Regulation of these pumps, exchangers and ion channels by the glycolytic process has important consequences in a variety of physiological and pathophysiological processes, and a better understanding of this mode of regulation may have important consequences for developing future strategies in combating disease and developing novel therapeutic approaches.
Relative potency estimates of acceptable residues and reentry intervals after nerve agent release

In the event of an unplanned release of a chemical warfare agent during any stage of the Chemical Stockpile Disposal Program, the potential exists for off-post contamination of drinking water, forage crops, grains, garden produce, and livestock. The more persistent agents, such as the organophosphate nerve agent VX, pose the greatest human health concern for reentry. A relative potency approach comparing the toxicity of VX to organophosphate insecticide analogues is developed and used to estimate allowable residues for VX in agricultural products and reentry intervals for public access to contaminated areas. Analysis of mammalian LD50 data by all exposure routes indicates that VX is 10(3) to 10(4) times more toxic than most commercially available organophosphate insecticides. Thus, allowable residues of VX could be considered at concentration levels 10(3) to 10(4) lower than those established for certain insecticides by the U.S. EPA. Evaluation of reentry intervals developed for these organophosphate analogues indicate that, if environmental monitoring cannot reliably demonstrate acceptable levels of VX, restricted access to suspect or contaminated areas may be on the order of weeks to months following agent release. Planning for relocation, mass care centers, and quarantine should take this time period into account.
The Purposeful-Action Sequence and the "Illusion of Control" The Effects of Foreknowledge and Target Involvement on Observers' Judgments of Others' Control Over Random Events

This study examined how features of both the situation and the target's behavior may lead observers to infer that a target has exerted control over a random event-in this case a roll of the dice in a game of backgammon. Observers read stories about a game of backgammon in which the male target either strongly wished for one particular outcome of the roll of the dice or was indifferent and in which either the target rolled the dice himself or a third party rolled the dice for him. Results showed that when the target desired a particular consequence of the dice roll in advance and rolled the dice himself, observers were more likely to see him as having exerted influence over the dice roll, were willing to wager more that he could roll the same number again, and rated luck as less influential in producing the dice roll outcome. These results are discussed from the perspective of illusory perceptions of control that might explain why observers inferred an actor's intentions from the actor's production of an e...
The Trials and Tribulations of Josef K. and Meursault

Kafka's and Camus' social criticism is epitomized in their condemnation of a specific institution: the trial. Though the former prefers satire to the latter's more direct approach, each levels a scathing attack on societal norms. While the satire in Der Prozess does not contribute much to the plot as a whole, serving primarily as a metaphor, in L'Etranger Camus is more successful in integrating his attack on bourgeois justice with his existential plot. Though Josef K. and Meursault have rather tragic roles to play, the two novels do not present a pessimistic view of man's fate. L'Etranger is even rather optimistic. Camus chooses to end, not with Meursault's nihilistic tirade or with his execution but on a note of tranquil reflection. Through their failure as individuals the two heroes offer positive hope to the rest of mankind. They are scapegoats who are sacrificed to save the reader from the same fortune. Both authors specifically address themselves to the latter and urge him to reflect on the problems dramatized in their works. That K. and Meursault are possessed by a strong desire to live at the end stresses the infinite value of life despite its tragic brevity.
Mission Trades for Aerocapture at Neptune

A detailed Neptune aerocapture systems analysis and spacecraft design study was performed to improve our understanding of the techonology requirement for such a hard mission. The primary objective was to engineer a point design based on blunt body aeroshell technology and quantitatively assess feasibility and performance. This paper reviews the launch vehicle, propulsion, and trajectory options to reach Neptune in the 2015-2020 time frame using aerocapture and all-propulsive vehicles. It establishes the range of entry conditions that would be consistent with delivering a - 1900 kg total entry vehicle maximum expected mass to Neptune including a - 790 kg orbiter maximum expected mass to the science orbit. Two Neptune probes would be also be delivered prior to the aerocapture maneuver. Results show that inertial entry velocities in the range of 28 to 30 km/s are to be expected for chemical and solar electric propulsion options with several gravity assists (combinations of Venus, Earth and Jupiter gravity assists). Trip times range from approximately 10-11 years for aerocapture orbiters to 15 years for all-propulsive vehicles. This paper shows that the use of aerocapture enables this mission given the payload to deliver around Neptune compared to an all-propulsive orbit insertion approach. However, an all-propulsive chemical insertion option is possible for lower payload masses than the one needed for this science mission. Both approaches require a Delta IV heavy class launch vehicle.
Tunnel kiln for firing large refractory products

A tunnel kiln has been put into operation for firing large products in which cycles were worked out for firing blocks for the glass industry. When these products are being fired in the tunnel kiln loss is reduced by a factor of 10 compared with loss obtained when firing them in round furnaces. There are appreciable reductions in labor expenditure, and the working conditions are improved. Setting and unloading are mechanized.
Experimental study of spinning combustion in a mesoscale divergent channel

Abstract Quasi-steady and unsteady propagations of methane and propane–air premixed flames in a mesoscale divergent channel were investigated experimentally and theoretically. The emphasis was the impact of variable cross-section area and the flame-wall coupling on the flame transition between different regimes and the onset of flame instability. Experimentally, for the first time, spinning flames were observed in mesoscale combustion for both lean and rich methane and propane–air mixtures in a broad range of equivalence ratios. The spinning flames rotated in either clockwise or counterclockwise direction with equal probability. The results showed that for a fixed equivalence ratio, there was a critical flow rate, above which flame starts to spin. The spin frequency was approximately proportional to the flame speed. It was also found that the spinning flame only occurred after the transition from fast flame regime to slow flame regime. The flame propagation speed and the effective Lewis number were obtained analytically. Experimental observation and theoretical analysis suggested that regardless of the magnitude of mixture Lewis numbers, the flame-wall coupling will significantly increase the effective Lewis number and lead to a new mechanism to promote the thermal diffusion instability.
Physical and Biochemical Properties of Porcine Muscle as Affected by Exogenous Epinephrine and Prednisolone

SUMMARY— The effects of intramuscular ante-mortem epinephrine of prednisolone plus epinephrine injection upon some physical and biochemical properties of porcine longissimus dorsi muscles were studied. Rate of post-mortem muscle pH decline, ultimate muscle pH, Munsell value and transmission value were not significantly (P > .05) altered by epinephrine or prednisolone plus epinephrine injection. Significantly (P < .05) higher total phosphorylase activity and slightly greater phosphorylase a and % phosphorylase u (% of total phosphorylase activity) were observed in the muscles of epinephrine injected pigs. Neither total phosphorylase nor phosphorylase a was related to rate of pH decline or incidence of pale, soft, exudative muscle development. Muscle concentrations of AMP and IMP were not significantly (P > .05) different between treatments. IMP concentration was highly related to rate of pH fall. Correlation coefficients between longissimus dorsi muscle pH and IMP levels were −.93 and −.94 at 1.5 and 45 min post-mortem, respectively. Prednisolone treatment resulted in higher initial and ultimate muscle glycogen levels than those from the control or epinephrine injected pigs.
Moment-Based Acceleration for Neutral Gas Kinetics with BGK Collision Operator

In this work, we present a moment-based accelerator algorithm for a Picard iteration applied to a neutral gas dynamics Boltzmann transport equation with a Bhatnagar-Gross-Krook collision operator. Traditional approaches relying on either explicit or Picard iteration schemes (i.e., source iteration) are severely limited for investigating time-scales much larger than the collisional relaxation time-scale, τ. We have developed a nonlinear accelerator algorithm that allows one to step over this stiff collision time scale and follow the hydrodynamic time scale of the problem when appropriate. The new algorithm relies on formulating a nonlinear, coupled system comprised of a high-order (HO) kinetic equation and a low-order (LO) fluid moment equation system. The HO equation provides self-consistent closures to the LO fluid equations, while the latter provides the required implicit-moment variables to evaluate the collision operator. We characterize the performance of the new algorithm on a Sod shock tube and a s...
Ribozyme-mediated cleavage of a substrate analogue containing an internucleotide-bridging 5'-phosphorothioate: evidence for the single-metal model.

An oligonucleotide substrate containing a 5‘-bridging phosphorothioate linkage adjacent to a ribonucleotide has been used to investigate the cleavage mechanism of the hammerhead ribozyme and to probe the catalytic role of the metal cofactor(s). Specifically, we tested the hypothesis that a second metal interacts with the 5‘-leaving group to facilitate the cleavage event. To this end, we have examined the ribozyme-mediated cleavage activity of the phosphorothioate substrate at pH 7.5 with a series of divalent metals in both the presence and absence of the polycation spermine. The cleavage products are found to be the same as for the native sequence under a variety of reaction conditions. The influence of divalent metal ion concentration, temperature, and pH on the cleavage rate has also been examined for both the oxo linkage and the thio analogue. Spermine (but not spermidine or NaCl) is shown to support efficient cleavage of the thio analogue in the absence [5 mM ethylenediaminetetraacetic acid (EDTA)] of...
Anisotropic growth of reactor fuel pin cladding

Abstract Anisotropic growth of 316 stainless steel reactor fuel pin cladding was found to occur after irradiation in the Experimental Breeder Reactor-II (EBR-II). Pressurized tube specimens were irradiated to a peak fluence of 10 23 n / cm 2 ( E >0.1 MeV ) at temperature ranging from 430°C to approximately 590°C. Growth was observed in both the annealed and 20% cold worked conditions and was found to decrease with increasing hoop stress. The anisotropic growth is more pronounced in the cold worked condition. The growth is attributed to a preferred orientation of Burgers vectors in the preirradiated cold worked dislocation structure.
Surgery for aortic stenosis in children: a 40-year experience.

Abstract Background Aortic stenosis (AS) is encountered in approximately 5% of children with heart disease. The indications for surgery and the surgical techniques for AS are well established. This report focuses on the early and long-term outcomes in children with AS over a 40-year period. Methods Included in this study were 508 patients ranging in ages from 1 day to 19 years, who were operated on for AS between 1960 and 2002 . Eighty-one percent (414 of 508) of the patients had left ventricular outflow tract obstruction (LVOTO) at a single level: 40 supravalvar, 242 valvar (critical AS in 85 neonates and young infants and in 157 older children), and 132 subvalvar. Nineteen percent (94 of 508) of the patients had LVOTO at more than one level. Associated congenital cardiac defects were found in 32% of the patients. Results The overall hospital mortality rate was 8% (40/508) with neonates with critical AS having the highest mortality (33%). The late mortality was 4% for the entire group. Follow-up was 95% complete. The mean follow-up was 8.5 ± 7.1 years. In the subgroup with multilevel LVOTO (n = 94), the average intraoperative peak systolic left ventricular-aortic gradient decreased from 80 to 22 mm Hg after repair but increased progressively to 74 ± 36 mm Hg ( p Conclusions Surgical relief of LVOTO in infants and children can be accomplished with low mortality and morbidity. Neonates with critical AS have significantly higher mortality and morbidity due to their complex anatomy and their critical presentation that affects outcome. Aortic valvotomy delays valve replacement in a significant percentage of children. The Ross procedure and mechanical aortic valve replacements have had a low mortality and morbidity in our series. Valve replacement will eventually be required in most children presenting with valvar AS and multilevel LVOTO while repair of discrete subaortic stenosis and supravalvar AS may not require reoperation in most patients. Children with LVOTO should have lifetime follow-up.
Pulmonary angiogenesis in a rat model of hepatopulmonary syndrome.

Background & Aims Hepatopulmonary syndrome (HPS), defined as intrapulmonary vasodilation, occurs in 10%–30% of cirrhotics and increases mortality. In a rat model of HPS induced by common bile duct ligation (CBDL), but not thioacetamide (TAA)-induced nonbiliary cirrhosis, lung capillary density increases, monocytes accumulate in the microvasculature, and signaling factors in the angiogenesis pathway (Akt and endothelial nitric oxide synthase [eNOS]) are activated. Pentoxifylline (PTX) directly decreases lung endothelial Akt and eNOS activation, blocks intravascular monocyte accumulation, and improves experimental HPS; we evaluated whether pulmonary angiogenesis develops in this model. Methods TAA- and PTX-treated animals were evaluated following CBDL. Lung angiogenesis was assessed by quantifying factor VIII-positive microvessels and levels of von Willebrand factor (vWf), vascular endothelial cadherin (VE-cadherin), and proliferating cell nuclear antigen (PCNA). Angiogenic factors including phospho-Akt, phospho-eNOS, vascular endothelial growth factor (VEGF)-A, and phospho-VEGF receptor-2 (p-VEGFR-2) were compared and monocyte accumulation was assessed. Results Following CBDL, but not TAA exposure, rats developed HPS that was temporally correlated with increased numbers of lung microvessel; increased levels of vWf, VE-cadherin and PCNA; and activation of Akt and eNOS. Angiogenesis was accompanied by increased pulmonary VEGF-A and p-VEGFR-2 levels, with VEGF-A staining in accumulated intravascular monocytes and alveolar endothelial cells. Following CBDL, PTX-treated rats had reduced numbers of microvessels, reduced lung monocyte accumulation, downregulation of pulmonary angiogenic factors, and reduced symptoms of HPS. Conclusions A specific increase in pulmonary angiogenesis occurs as experimental HPS develops, accompanied by activation of VEGF-A-associated angiogenic pathways. PTX decreases the angiogenesis, reduces the symptoms of HPS, and downregulates VEGF-A mediated pathways.
The growing role of computers in american federal tax compliance and administration

Computers have had a significant impact on reducing both compliance and administrative costs under the American Federal Internal Revenue Code. Computer assisted legal research systems have vastly facilitated legal research for both taxpayer and tax collecting officials. Tax evasion and under-reporting have been brought under better control with the assistance of computers. At present successful experiments are being conducted under which returns prepared by the taxpayer with the assistance of computers are being filed in electronic format so as to allow for virtual instant processing by tax collecting officials. Taxpayers have also found computers to be of considerable assistance in preparing tax returns and developing tax saving strategies.
Autoradiographic studies of t12/t12 mouse embryos†

SUMMARY High-resolution autoradiographic studies were used to determine whether t 12 /t 12 and Z"' 32 //" 32 mouse embryos synthesize the excessive lipid which distinguishes these embryos prior to their death. The studies show that the t n homozygotes synthesize neutral lipid which is stored in intracellular lipid droplets. Cholesterol and phospholipid precursors are not incorporated into these droplets.
Gamma-Ray Burst Spectral Evolution Through Crosscorrelations of Discriminator Light Curves

Gamma-ray burst spectra usually show hard-to-soft evolution within intensity spikes and from spike to spike. The techniques used to study spectral evolution often lack sufficient temporal resolution to determine the nature of this evolution. By comparing the auto- and crosscorrelations between the time histories of the BATSE Large Area Detector discriminator rates I have characterized the spectral evolution of a sample of 209 bursts. I find that hard-to-soft evolution is ubiquitous, and only ~10% of the bursts show clear soft-to-hard evolution.
NANOSCALE VOID GROWTH IN MAGNESIUM: A MOLECULAR DYNAMICS STUDY

Molecular dynamics calculations were carried out in single crystal magnesium specimens to reveal the dependence of strain rate, temperature, and orientation of the crystal on damage evolution as defined by pore growth. Two specific crystallographic orientations [0001] and were examined. During a [0001] tensile test, twin boundaries developed at the void surface leading to a constraint on the crystallographic orientation. On the other hand, during the tensile deformation, emission of shear loops in the prismatic slip planes arose when void growth initiated. Furthermore, analysis of the damage components (nucleation, growth and coalescence) revealed that a large number of small voids nucleated that rapidly grew and fractured the specimens independent of the temperature and the strain rate.
Water-vapour maser emission from galactic nuclei

We report here the progress of a survey of galactic nuclei for water-vapour maser emission at 22.235 GHz. We observed 29 late-type galaxies in November 1982, January 1983, and September 1983 using the 40-m radio telescope of the Owens Valley Radio Observatory (OVRO) equipped with a travelling-wave maser receiver1. We have detected maser emission from four nuclei: NGC4258 (M106), NGC1068 (M77), NGC3034 (M82), and NGC6946. The masers in NGC4258 and NGC1068 are extremely luminous; NGC1068 has the most luminous water-vapour maser yet reported—350 L⊙ assuming isotropic emission. We suggest that the extremely bright nuclear masers indicate an ongoing burst of star formation, and therefore provide a useful probe of the physical conditions of the starburst phenomenon.
Exploring self‐management characteristics in youths with type 1 diabetes mellitus: does membership in a glycemic control category matter?†

Kichler JC, Kaugars AS, Ellis J, Alemzadeh R. Exploring self-management characteristics in youths with type 1 diabetes mellitus: does membership in a glycemic control category matter? Background: Hemoglobin A1c (HbA1c) levels have been shown to worsen in adolescence and be related to long-term diabetes complications. Although categories of diabetes control (e.g., ideal, satisfactory, and poor) are routinely used in clinical practice, research has not fully explored whether these categories meaningfully distinguish between different self-management characteristics. Objectives: This study examines potential differences in self-management characteristics for youths and their caregivers for three different categories of diabetes control (e.g., ideal, satisfactory, and poor control). Methods: A total of 69 adolescents (35 M/34 F) with type 1 diabetes mellitus (T1DM) (aged 12–17 yr) and their caregivers completed questionnaires of readiness to change the balance of responsibility for diabetes tasks, family responsibility in diabetes management, and self-efficacy for diabetes. A medical record review yielded demographic information, most recent HbA1c level, and health care utilization over the past year. Results: Youths in the three different categories of diabetes control demonstrated no significant differences on measures of self-management characteristics. Maternal caregivers from the satisfactory control category and youths in the poor control category demonstrated the most consistent responses across various self-management characteristics. Conclusions: Youths classified in different categories of glycemic control may not be as different in their self-management characteristics as was presumed. Moreover, associations among self-management characteristics were not universal across responders. Therefore, individual assessments of youths' and caregivers' self-management characteristics need to occur independent of the youths' membership in a certain category of diabetes control.
Symmetry in Nonlinear Hydrologic Dynamics under Uncertainty: Ensemble Modeling of 2D Boussinesq Equation for Unsteady Flow in Heterogeneous Aquifers

In this paper, the probabilistic symmetry analysis approach proposed in the previous paper by Cayar and Kavvas in 2009 is adopted and applied to the analysis of nonlinear two-dimensional (2D) groundwater flow subject to random hydraulic conductivity field. The resulting model has the form of a two-dimensional Fokker-Planck equation (FPE). Following the methodology reported by Cayar and Kavvas in 2009, the 2D Boussinessq equation for unconfined groundwater flow in a heterogeneous aquifer is transformed to a system of ordinary differential equations (ODEs) through Lie group symmetry analysis in order to eliminate the spatial derivatives occurring in the governing equation. Next, these derived stochastic ODEs are ensemble averaged with second-order cumulant expansion and converted into a linear, deterministic partial differential equation. This new equation is called the FPE, and describes the evolution of the probability density function (PDF) of the hydraulic head, thereby, describing the ensemble behavior...
Depressed plasma retinol-binding protein (RBP) in cystic fibrosis (CF)

Decreased plasma levels with normal or increased liver stores of vitamin A were reported previously in CF patients orally supplemented with water-miscible vitamin A. These findings suggested a defect in the mechanism by which vitamin A is transported from the liver in patients with CF. Plasma levels of RBP, the specific carrier protein for vitamin A, have been measured by radioimmunoassay in 69 samples from 49 CF patients and in 96 normal age-matched controls. Mean RBP levels (± SEM) in CF, 24.4 ± 1.3 μg/ml, were significantly (p < .001) lower than in normal controls, 37.3 ± 1.3 μg/ml. In normal children 14 years and under, plasma RBP and vitamin A levels showed a signification (p < .001) correlation with age; in contrast no age-related rise was observed in CF children of comparable age. Saturation of RBO with vitamin A was less than normal (p < .004), and the levels of plasma prealbumin (the protein normally complexed with RBP) were decreased (p < .001) in the CF group 15 years and older compared with controls. Depressed plasma RBP levels were not correlated with plasma G.O.T. or albumin levels. These results suggest that a defect in the hepatic production and/or secretion of RBP occurs in CF.
Adaptive Neurocontrollers for Vibration Suppression of Nonlinear and Time Varying Structures

Neural network based control systems with online adaptation are capable of coping with system uncertainty, nonlinearity, and variations with time. The current article presents a comparison of neurocontrollers with a standard LQR control system for vibration reduction. Controller performances are tested using an experimental setup employing a cantilevered plate with surface bonded PZT actuators. The large accelerations due to sinusoidal (first and second mode) disturbances cause geometric nonlinearity. Time variations of system dynamics (by adding mass or attaching modification plate) and external excitations are investigated. The results are presented in both time and frequency domains and the measurement uncertainties are identified. The results show that neural adaptive predictive controller is very promising in terms of control effectiveness and control effort in the vibration suppression of nonlinear, time varying smart structures.
Intraaortic Balloon Pumping Through the Common Iliac Artery: Management of the Ambulatory Intraaortic Balloon Pump Patient

Indications for use of the intraaortic balloon pump have expanded as advances in the treatment of heart disease have continued. The intraaortic balloon pump is the most widely used circulatory assist device inserted as short term or long term therapy. Because the percutaneous femoral artery approach requires bedrest, new techniques for intraaortic balloon pump insertion that allow greater mobility are being developed for patients who require long term ventricular support. The goal of ambulation in these patients is to prevent potential complications associated with prolonged immobility. This paper reviews the use of the common iliac artery as an alternate site for intraaortic balloon pump insertion that allows the patient to ambulate and exercise. Pre and post procedure management as well as potential complications of intraaortic balloon pump insertion are discussed.
Efficient designs for animal carcinogenicity experiments

In a typical carcinogenicity study, animals, usually rats or mice. are divided into a control and two to three dose groups of 50 or more by randomization. A chemical is administered at a constant daily dose rate for a major portion of the lifetime of the test animals, for example, two years. In general, such an experiment is expensive and time consuming In this paper, we propose an efficient design with reduced sample size and/or shortened study duration. An equal number of animals per dose group is considered in this study. A power study of the age-adjusted trend test, for the turnor incidence rate for single-sacrifice experiments proposed by Kodell et al. (Drug Information Journal, 1997) is conducted. A Monte Carlo simulation study is performed to compare the performance of the trend test for the standard design and various reduced designs. Based on the Kodell et al. test, the 21-month study duration with sample size 50 per group is recommended as the best, reduced design over the traditional 2-year stu...
Pressure Ulcers: Prevention and Management

Objective To describe important aspects of pressure ulcer prevention and management, especially in elderly patients. Design We reviewed pertinent published material in the medical literature and summarized effective strategies in the overall management of the elderly population with pressure ulcers. Results Pressure ulcers are commonly encountered in geriatric patients. The development of a pressure ulcer is associated with an increased risk of death. Certain well-recognized risk factors, such as immobility and incontinence, may predispose to the development of pressure ulcers; consequently, risk factor modification is an important aspect of prevention and treatment. For existing lesions, various innovative patient support surfaces and wound care products have been developed to alleviate pressure and to facilitate wound healing. The use of a particular product should be based on the clinical setting and the limited scientific evidence available. With treatment, most pressure ulcers eventually heal. Conclusion Pressure ulcers are often, but not always, preventable. The occurrence of such an ulcer signals the possible presence of chronic comorbid diseaseand should prompt a search for underlying risk factors in patients for whom ulcer treatment is considered aDPropriate.