cssi/SciSciGPT-SciSciNet huggingface dataset:
Catalytic and stoichiometric multielectron reduction of hydrazine to ammonia and acetylene to ethylene with clusters that contain the MFe3S4 cores (MMo, V). Relevance to the function of nitrogenase

Abstract A functional model for nitrogenase is currently sought in our laboratory in reactivity studies using various single cubane clusters that possess the [MFe 3 S 4 ] n + core, (MMo, n = 3; MV, n = 2). These clusters are used as catalysts for the reduction of enzymatically relevant substrates. Substrates such as hydrazine and acetylene are catalytically reduced by (NEt 4 ) 2 [(Cl 4 -cat) (CH 3 CN) MoFe 3 S 4 Cl 3 ], I , to ammonia and ethylene respectively, in the presence of added protons and reducing equivalents. Hydrazine also is catalytically reduced by the (NEt 4 ) [(DMF) 3 VFe 3 S 4 Cl 3 ] cubane under similar conditions. Gas chromatography was employed to monitor the reduction of acetylene to ethylene and a trace of ethane. Catalysis in excess of 100 turnovers (for hydrazine reduction) and in excess of 15 turnovers (in acetylene reduction) has been demonstrated over a period of 24 h. A study of the acetylene reduction reveals saturation kinetics to be operating at high substrate concentrations. A variable temperature kinetic study of acetylene reduction shows a moderate activation energy ( E act = 9(1) kcal mol −1 ) but a large entropy of activation ( ΔS ‡ = −32(2) cal K −1 mol −1 ) which extrapolates to a significant Gibbs free energy ( ΔG ‡ = 19(1) kcal mol −1 ). These results are consistent with an ordered transition state. Considerable evidence has been amassed which directly implicates the Mo and V atoms as the primary catalytic sites. Replacement of the Mo or V bound, kinetically labile, solvent molecules with non-labile ligands acts to suppress the observed rates of reaction. The Fe sites on I are totally inactive in the reduction of hydrazine, however they have been found to effect acetylene reduction albeit at a markedly reduced rate compared to the Mo site. Catalyst integrity has also been demonstrated by a variety of techniques, primarily EPR spectroscopy which identifies the characteristic S = 3 2 signals of the Mo and V cubanes after at least 18 h reaction time.
Presence and regulation of α-ketoglutarate dehydrogenase complex in a glutamate-producing bacterium, Brevibacterium flavum

The presence of α-ketoglutarate (α-KG) dehydrogenase complex in the glutamate-producing bacteria was demonstrated for the first time with Brevibacterium flavum. The partially purified enzyme, which was specific to KG and NAD+ with the usual requirements for other co-factors, was labile and stabilized by glycerol, Mg2+, and thiamine pyrophosphate. The enzyme showed an optimum pH of 7.6 and Kms of 80, 86, and 61 μm for KG, NAD+, and CoA, respectively, cis-Aconitate, succinyl-CoA, NADPH, NADH, pyruvate, and oxalacetate strongly inhibited the activity, while it was activated by acetyl-CoA, but not by AMP. Various inorganic and organic salts also inhibited the activity. When cells were cultured in glucose and acetate media, the specific activity of the cell extracts increased markedly and reached to a maximum at the late-logarithmic phase. Then, it decreased to the basal level. The addition of glutamate stimulated the synthesis of the enzyme.
Endothelin-1 Pulmonary Vasoconstriction in Rats with Diaphragmatic Hernia

Abstract Background. Pulmonary hypertension is an important cause of mortality in infants with congenital diaphragmatic hernia (CDH). Endothelin-1 has been implicated as a mediator of pulmonary hypertension. ET-A receptors are increased in the nitrofen model of CDH in rats. We hypothesized that vasoconstrictor responses to endothelin-1 are increased in pulmonary arterioles of rats with nitrofen-induced CDH. Materials and methods. CDH was induced in fetal rats by feeding nitrofen (2,4-dichlorophenyl- p -nitrophenyl ether) to pregnant rats at midgestation. Third-generation pulmonary arterioles were isolated on the final day of gestation. Arterioles were cannulated and perfused at constant pressure with a physiologic salt solution. Diameters of arterioles from control animals ( n = 8), CDH animals ( n = 5), and animals exposed to nitrofen but without CDH ( n = 4) were measured. Responses to endothelin-1 concentrations of 10 −12 to 10 −8 M were compared by Student's t test. Results. CDH arterioles constricted more than controls in response to endothelin-1 at concentrations of 10 −11 M (29 ± 11% vs 5 ± 3%, P = 0.02) and 10 −10 M (40 ± 14% vs 9 ± 6%, P = 0.04). The log concentration of endothelin-1 that induced half-maximal response (ED 50 ) was lower for CDH arterioles than for control arterioles (−10.3 ± 0.6 vs −9.1 ± 0.2, P = 0.03). Responses of arterioles from animals exposed to nitrofen but without CDH were not different from controls ( P ≥ 0.05). Conclusions. Exaggerated vasoconstrictor responses to endothelin-1 may contribute to pulmonary hypertension in CDH.
A unified RANS-LES model

Large eddy simulation (LES) is computationally extremely expensive for the investigation of wall-bounded turbulent flows at high Reynolds numbers. A way to reduce the computational cost of LES by orders of magnitude is to combine LES equations with Reynolds-averaged Navier-Stokes (RANS) equations used in the near-wall region. A large variety of such hybrid RANS-LES methods are currently in use such that there is the question of which hybrid RANS-LES method represents the optimal approach. The properties of an optimal hybrid RANS-LES model are formulated here by taking reference to fundamental properties of fluid flow equations. It is shown that unified RANS-LES models derived from an underlying stochastic turbulence model have the properties of optimal hybrid RANS-LES models. The rest of the paper is organized in two parts. First, a priori and a posteriori analyses of channel flow data are used to find the optimal computational formulation of the theoretically derived unified RANS-LES model and to show that this computational model, which is referred to as linear unified model (LUM), does also have all the properties of an optimal hybrid RANS-LES model. Second, a posteriori analyses of channel flow data are used to study the accuracy and cost features of the LUM. The following conclusions are obtained. (i) Compared to RANS, which require evidence for their predictions, the LUM has the significant advantage that the quality of predictions is relatively independent of the RANS model applied. (ii) Compared to LES, the significant advantage of the LUM is a cost reduction of high-Reynolds number simulations by a factor of 0.07 Re 0.46 . For coarse grids, the LUM has a significant accuracy advantage over corresponding LES. (iii) Compared to other usually applied hybrid RANS-LES models, it is shown that the LUM provides significantly improved predictions.
Steroid hormones act directly to trigger segment-specific programmed cell death of identified motoneurons in vitro.

Abstract In larvae of the hawkmoth,Manduca sexta,accessory planta retractor (APR) motoneurons undergo a segment-specific pattern of programmed cell death at pupation. APR death is triggered hormonally by the prepupal peak of the ecdysteroid, 20-hydroxyecdysone (20-HE). Previous studies found no evidence that cellular interactions regulate the segmental pattern of APR deathin vivo.To test the hypothesis that 20-HE acts directly on APRs to trigger a cell-autonomous, segment-specific pattern of death, APRs were labeled with the fluorescent dyes DiI or DiA, removed from the nervous system before the prepupal peak, and placed in low-density cell culture. Physiological levels of 20-HE triggered the same segment-specific pattern of APR deathin vitroas seenin vivo,both in cultures containing a single APR and in cultures containing two APRs removed from the same donor animal. The presence or absence of contact with other cells did not influence the APRs’ responses to 20-HE. The death of APRs in culture was characterized by fragmentation or rounding up of the cell body and fragmentation of the neurites. These findings suggest that intrinsic segmental identity regulates whether these motoneurons live or die when exposed to a steroid hormone during development.
Hydrogenolysis: I. Nickel-kieselguhr as catalyst for the conversion of alcohols to ethers and hydrocarbons

Abstract The hydrogenolysis of alcohols in the presence of nickel-kieselguhr catalysts has been investigated in a micropulse reactor at 150–190 ° and at atmospheric pressure. Three main reactions occurred with primary aliphatic alcohols: reductive dehydroxymethylation, dehydroxylation, and the formation of ethers. The nickel-catalyzed conversion of alcohols to ethers is a novel reaction and can be applied even for the synthesis of neopentyl ether. The methods of preparation of nickel-kieselguhr affects the composition of the products. For the preferential formation of ethers the catalyst was prepared by precipitating the nickel from an aqueous nickel nitrate solution with ammonium carbonate. When potassium carbonate was used as the precipitating agent the yield of ether was lower. The intrinsic acidic sites of the catalyst appear to be responsible for the reductive dehydroxylation and for the formation of the ethers. Kieselguhr as such was not a catalyst for these reactions, while a nonsupported nickel under certain conditions could influence the ether formation.
Redefinition of the genus Phanuromyia Dodd (Hymenoptera: Scelionidae)

Abstract The concept of the Australian genus Phanuromyia Dodd is expanded to include 9 species: P. bidentata n. sp., P. flavescens (Dodd) new combination, P. hysteropteri (Bin) new combination, P. necopinata Dodd, P. obscuripes (Pelov) new combination, P. oocida (Pelov) new combination, P. pulcherrima (Dodd) new combination, P. rufobasalis Dodd, and P. sacchii (Ogloblin) new combination. Representatives have been found worldwide, but the greatest diversity is in the Old World. The known hosts are eggs of Issidae and Fulgoridae (Hemiptera: Fulgoromorpha). The genus is contrasted with the crassiclava species group of Telenomus, another group also known to attack species of fulgoromorphs.
Enhancing Career Motivation in Late Career

Career motivation is usually examined among young or mid‐career workers. The older worker is left alone. Unfortunately, in an environment in which the older person represents the fastest growing segment of the labour force, this critical resource is being frittered away. Examination of current practices suggests a large portion of older workers are persuaded by their employers′ actions that their careers are at an end. Alternatives to extend and increase this group′s career motivation are discussed.
Intercalated disc protein, mXinα, suppresses p120-catenin-induced branching phenotype via its interactions with p120-catenin and cortactin

The Xin repeat-containing proteins, Xinα (Xirp1) and Xinβ (Xirp2), localize to the intercalated discs (ICDs) of mammalian hearts. Mouse Xinα (mXinα) directly interacts with β-catenin and actin filaments, potentially coupling the N-cadherin/β-catenin complexes to the underlying actin cytoskeleton and modulating ICD integrity and function. Supporting this possibility, mXinα-null hearts develop ICD structural defects and cardiomyopathy with conduction defects. However, the underlying mechanisms leading to these defects remain unclear. Here, we showed that mXinα also interacted with p120-catenin and cortactin. Different from the β-catenin binding domain, there existed multiple p120-catenin binding sites on mXinα, while only the extreme N-terminus of mXinα containing a SH3-binding motif could interact with cortactin. In mouse heart, a significant fraction of cortactin was co-localized with N-cadherin to ICDs, whereas in mXinα-null heart, this fraction of cortactin was drastically reduced. Therefore, mXinα may modulate ICD integrity and function through its interactions with catenins and cortactin. Analyses of the in vivo consequence of p120-catenin and mXinα interaction revealed that force-expressed mXinα or its fragments significantly suppressed the p120-catenin-induced branching phenotypes. It is known that p120-catenin directly regulates Rho GTPases, leading to the branching phenotype. Thus, mXinα may sequester the p120-catenin from inhibiting RhoA activity and/or from activating Rac1 activity.
Pain and self-assessed health: does the association vary by age?

Abstract The association between pain and self-assessed health among adults age 20 and older is examined with data from the 2003–2004 National Health and Nutrition Examination Survey, a cross-sectional nationally representative survey of the civilian, non-institutionalized US population. Models emphasize whether and how the association differs across age cohorts. 5032 respondents age 20 and older were asked about their experience with pain. Responses are used to create two different pain measures: general and site-specific. Self-assessed health is categorized into groups that are ordered from fair/poor to excellent. Bivariate analyses and ordered logistic regressions reveal pain, measured both ways, have robust inverse associations with self-assessed health. Associations remain robust after adjusting for a series of health conditions and indicators plus demographic, socioeconomic and social support characteristics. Models test the effect of age by pain interactions on self-assessed health and confirm substantial variation across cohorts. Those of middle-age, 40–59, display the strongest association while self-assessed health is virtually unassociated among older–old, those 80 and older. Findings suggest that the way pain impacts self-assessed health varies by age cohort. Conclusions discuss the importance of considering pain as a health condition and the implications of the findings for well-being across age cohorts.
Aerobic oxidation of tetrahydrofuran by a series of iron (III) containing POSS compounds

Abstract A series of iron (III) containing POSS compounds, [Bu4N][(R)7Si7O12FeCl] (R = isobutyl- (1), ethyl- (2), phenyl- (3), and cyclopentyl- (4)) were investigated as potential catalysts for aerobic oxidation of tetrahydrofuran (THF). The oxidation products for this reaction were characterized by IR, GC and GC–MS. The major oxidation product was γ-butyrolactone (C4H6O2, GBL); while the two minor products were 2-hydroxy-THF and its tautomer, 4-hydroxybutanal. A third minor oxidative product is believed to be an isomer of dihydroxy-THF. THF free syntheses of 2–4 have been developed and all three compounds were characterized by elemental analysis, IR, and X-ray diffraction studies. The crystallographic data for 1–4 demonstrate a similar iron coordination sphere between the four compounds, but the different substitutents on the various POSS. The corresponding turnover numbers for the aerobic oxidation of THF suggest that smaller substitutents on the POSS ligands improve the stability of the catalytic species. When compared to other published catalytic iron systems, these turnover numbers appear to be the largest for the aerobic conversion of THF to GBL.
Measurement and Analysis of Tissue Temperature During Microwave Liver Ablation

We measured tissue temperature changes during ex vivo microwave ablation (MWA) procedures for bovine liver tissue. Tissue temperature increased rapidly at the beginning of the MW power application. It came to a plateau at 100 degC to 104 degC before it increased again. We split the changes of tissue temperature versus time into four phases. This suggests that tissue temperature changes may be directly related to tissue water related phenomena during MWA, including evaporation, diffusion, condensation and tissue water composition. An additional analysis indicated the lesion boundary at ~50 degC to 60 degC temperature. We also measured the water content of ablated tissue lesions and examined the relationship of tissue water content and tissue temperature by mapping temperature to remaining tissue water after ablation. The results demonstrate significant tissue water content changes and lead to a better understanding of tissue water movement
Stimulation of limb regeneration in the lizard Xantusia vigilis by means of ependymal implants.

The experiments reported in this paper demonstrate that ependymal cells can stimulate a regenerative outgrowth when implanted into the limb of a lizard. Simple limb amputation, amputation followed by a sham operation, and amputation followed by the implantation of a cartilage tube from a tail regenerate were ineffective in causing the hind limbs of Xantusia vigilis to regenerate. However, amputation followed by the implantation of a cartilage tube containing ependyma caused regenerative outgrowths in 82% of the treated limbs. These results show that ependymal cells, in addition to initiating tail regeneration in their normal location, can when transplanted to the limb, initiate limb regeneration.
Operations in the homology spectral sequence of a cosimplicial infinite loop space

Consider the mod 2 homology spectral sequence associated to a cosimplicial space X. We construct external operations whose target is the spectral sequence associated to EΣ2×Σ2(X×X). If X is a cosimplicial E∞-space, we couple these external operations with the structure map EΣ2×Σ2(X×X)→X to produce internal operations in the spectral sequence. In the sequel we show that they agree with the usual Araki–Kudo operations on the abutment H∗(TotX).
Immunosenescence of the Equine Immune System

It is widely recognized that advanced age is associated with alterations in immunological responses that likely contribute to increased morbidity and mortality in the elderly population. This decreased efficacy of the immune system with age is referred to as 'immunosenescence' and has been reported for a number of species. Similar age-related changes are seen in horses and are manifested as decreased responsiveness to vaccination in vivo and diminished proliferative responses to mitogens in vitro. The underlying mechanism responsible for these impaired immunological responses remains unknown. This paper reviews some of our recent findings on immunosenescence in horses. Recent results on the immune response of aged horses to vaccination with a novel recombinant influenza vaccine are also discussed.
The OECD and the local: PISA-based Test for Schools in the USA

The Organization for Economic Cooperation and Development (OECD) has recently piloted the Program for International Student Assessment (PISA)-based Test for Schools in the USA. In this paper, I contend that by connecting directly with local school boards this new initiative has the potential to further promote the OECD's educational agenda in local policy debates. I begin to develop this argument by providing an overview of the OECD and its work. I then lay out a theoretical framework around global governance and knowledge production within the context of the OECD. Next, I provide a brief overview of the traditional PISA study and compare it to the new PISA-based Test for Schools initiative. This context provides the foundation for a discussion of the ways in which a school-based international assessment can operate as a governance tool, allowing international organizations to have greater influence in the formation and implementation of local educational policies.
IN TOUCH AT LAST

Earlier this year Science asked readers to imagine what life would be like in the year 2050. As described in the editorial on page 1851, we now present the first of four installments of these fictional essays.
Effects of stimulus ear presentation on the voice reaction time of adult stutterers and nonstutterers

Abstract The initial and optimum voice reaction times (VRT) to auditory stimuli presented separately to the left and right ears of ten adult stutterers and ten nonstutterers was investigated. Subjects initiated the neutral vowel sound /Λ/ in response to one hundred 4000 Hz tones of 2.5 sec in duration. The silent intervals between the tones varied randomly. The stimulus cues were divided into five equal response sets of 20 tones each with 10 tones in each set being presented to the right ear and 10 tones to the left ear alternating back and forth. No significant differences were reported between the VRTs for cues presented to the left or right ears for either group. However, the stutterers exhibited voice reaction times which were significantly longer and more variable than those of the nonstutterers. The between- group differences were observed for what appeared to be the “optimum” level of voice initiation for the experimental task. These results lend to the speculative hypothesis that the observed difficulty for adult stutterers to promptly and consistently initiate vocalization may in part be attributable to inherent rather than learned factors.
MicroRNA expression patterns in medullary and extramedullary plasmacytoma

Plasmacytomas are localized tumors of monoclonal plasma cells without evidence of significant bone marrow infiltration or systemic myeloma, comprising ∼2–10% of all plasma cell neoplasms.1 Medullary plasmacytomas classically occur in the bone of the vertebrae or skull, whereas extramedullary plasmacytomas occur in the soft tissues, most frequently in the head and neck region involving the sinuses or rhinopharynx.1 Both medullary and extramedullary plasmacytomas occur in males more often than in females with a median age at diagnosis of 54 years.1 Furthermore, plasmacytomas in general are fairly radiosensitive, such that the current treatment of choice is localized radiation therapy except in cases of neurologic compromise or bone instability that require surgical resection.2 There is no evidence thus far that adjuvant systemic chemotherapy offers additional clinical benefit.2 Despite these similarities, medullary and extramedullary plasmacytomas are considered distinct clinical entities owing to differences in their predisposition to evolve into multiple myeloma (MM). Medullary plasmacytomas are traditionally thought to have a higher risk of progression, also with a lower 5-year survival rate of 33% once they have progressed to MM (as opposed to 5-year survival rate of 100% in extramedullary plasmacytomas that progress to MM).2 Yet, very little is known regarding genetic or molecular factors that distinguish these two groups of plasmacytomas and influence their clinical outcome.
Amplification effect of platelet type nanoparticles on the orientation behavior of injection molded nylon 6 composites

Abstract The effect of platelet type nanoparticles and processing conditions; mold temperature and injection speed, on the development of local microstructure in injection molded nylon 6 parts was investigated. The molded parts exhibit two crystal forms (α and γ) of nylon 6 in varying proportions from skin to core. The γ crystals preferentially grow near the surface regions and α crystal fraction increases with distance from the surface in all molded parts. However, the spatial variation of crystal phases across the thickness in nanocomposites differs from that of unfilled nylon 6. Nanoplatelets induce high levels of orientation of the polymer matrix throughout the thickness of the molded part even at high mold temperatures where nonisothermal effects are highly suppressed and confined to very close proximity of surfaces. These high chain orientation levels observed in nanoparticle filled systems is a result of the shear amplification effect that occurs in small spaces between adjacent nanoparticles of differing velocity. The local preferential crystalline orientation of nylon 6 resin and nanoparticles across the thickness of the molded parts are investigated using a series of structure characterization techniques including microbeam wide angle X-ray, SAXS and TEM.
Synthesis of [1-14C]1,2-cyclohexanedione bis(4-diethylenoxythiosemicarbazone) and preliminary biodistribution studies of this potential antitumor agent.

A new compound, [1-14C]1,2-cyclohexanedione-bis(4-diethylenoxythiosemicarbazone) was found to have significant antitumor activity (% T/C = 245) when tested against sarcoma-180 ascites tumor in mice and thus may be a potentially useful drug. The compound can be easily labeled with 14C by employing the straightforward synthetic procedures detailed in this article. Results of the synthesis and purification are presented. Preliminary biodistribution studies of the labeled compound in both normal and tumor bearing mice were performed. The compound, when administered i.p., is rapidly absorbed and localized into most tissues. Urinary and biliary excretion are its major routes of elimination. Based on these studies, continued evaluation is recommended.
Wave erosion of a massive artificial coastal landslide

The Lone Tree landslide is located on the coast north of San Francisco, California, and is unusual in that it is positioned within the San Andreas fault zone. Its material ranges from mud through to boulders, which makes the slide particularly susceptible to mass movement. Movement of its western half increased following the Loma Prieta earthquake in 1989, closing an important highway for over a year, at which time a large cut-and-fill operation was undertaken to remove the upper portion of the slide so it would create no future disruption. Material cut from the upper slide was dumped below the highway, with the debris extending into the ocean. This created an artificial debris fill that is equivalent to a massive natural landslide, and a unique opportunity to monitor its erosion. Rainfall quickly eroded a series of rills into the face of the artificially created landslide, but the concentration of gravel and cobbles armoured these small channels, greatly reducing the rate of subsequent erosion. Waves cut away the toe, and the focus of this paper is on the development of a model to analyse the frequency of wave attack in terms of tide levels and wave conditions. A beach consisting of cobbles and boulders formed at the toe of the debris, offering partial protection and reducing the rate of continued erosion. In the short term, armouring of the rills and the development of a fronting beach have reduced the overall erosion of the debris and the transfer of sediment to the ocean. In the longer term, the formation of secondary slumps can be expected to renew the erosion. Eventually the morphology of the debris fill should approach the configuration of the natural landslide, an unmodified portion of which remains adjacent to the artificial fill. © 1998 John Wiley & Sons, Ltd.
Tritium release from lithium aluminate: can it be improved?

Lithium aluminate is an attractive material (in terms of its chemical, mechanical and irradiation properties) for breeding tritium in fusion reactors; however, its tritium release characteristics are not as good as those of other candidate materials. To investigate whether tritium release from lithium aluminate can be improved, we have studied the tritium release from irradiated samples of pure lithium aluminate, lithium aluminate doped with Mg, and lithium aluminate with a surface deposit of platinum. The release was studied by the temperature programmed desorption (TPD) method. Both the platinum coating and magnesium doping were found to improve the tritium release characteristics, as determined by TPD. Tritium release shifted to states with lower activation energies for the altered materials.
The effect of chemical-vapor-deposition conditions on the properties of carbon-carbon composites

Abstract Properties are given for as-deposited and heat-treated carbon-felt, carbon-matrix composites infiltrated at deposition temperatures of 1100 and 1400°C, and pressures of 20 and 630 Torr. A thermal stress figure of merit was calculated for each material, with the heat-treated composite infiltrated at 1400°C and 630 Torr yielding the highest value. As with most graphitizing carbon materials, heat-treatment resulted in a decrease of the flexural strengths and moduli. The strength-to-modulus ratios, however, increased, being highest for deposition conditions of 1400°C and 630 Torr. Heat-treatment also resulted in an increase in thermal conductivity and a decrease in thermal expansion. These changes were related to the degree of crystallinity and to the formation of cracks within the matrix.
The effect of surface chemistry on the formation of thin films of native fibrillar collagen.

Abstract In this study, we used well-defined, homogeneous, gradient and patterned substrates to explore the effects of surface chemistry on the supramolecular structure of adsorbed type I collagen. Type I collagen (320 μg/mL) was allowed to adsorb onto self-assembled CH3-, COOH-, NH2- and OH-terminated alkylthiolate monolayers at 37 °C. Atomic force microscopy, ellipsometry and phase microscopy indicated that large supramolecular collagen fibril structures (approximately 200 nm in diameter, several microns long) assembled only at the hydrophobic CH3-terminated surfaces. By varying the surface energy using a mixture of OH- and CH3-terminated thiols during monolayer formation, we found that large fibril assembly occurred at surfaces with a water contact angle above 83°, but not on surfaces with a water contact angle below 63°. Examining a surface with a linear hydrophobicity gradient revealed that the assembly of large collagen fibrils requires a hydrophobic surface with a water contact angle of at least 78°. Collagen fibril density increased over a narrow range of surface energy and reached near-maximum density on surfaces with a water contact angle of 87°. These studies confirm that the supramolecular structure of adsorbed collagen is highly dependent on the underlying substrate surface chemistry. We can take advantage of this dependency to pattern areas of fibrillar and non-fibrillar collagen on a single surface. Morphology studies with vascular smooth muscle cells indicated that only collagen films formed on hydrophobic substrates mimicked the biological properties of fibrillar collagen gels.
Pharmacokinetic modeling of bidirectional transfer during peritoneal dialysis

A pharmacokinetic model and distributional clearance terms to describe bidirectional peritoneal transfer were used to examine cefamandole pharmacokinetics in five uninfected patients with end-stage renal disease who were receiving continuous ambulatory peritoneal dialysis. Each patient received intravenous and intraperitoneal 1 gm doses of drug, and serum and dialysate samples were collected over three dialysis dwell periods. The mean systemic availability of cefamandole after intraperitoneal dosing was 0.71 ± 0.1. No significant differences in the serum-to-peritoneal fluid and peritoneal fluid-to-serum distributional clearances were observed. The time dependence of peritoneal dialysis clearance was examined. The amount of drug found in the dialysate divided by the corresponding serum AUC was empirically found to estimate the time-averaged peritoneal dialysis clearance. A mass balance-area method to calculate distributional clearance was developed that obviates more complicated computer fitting of the data. We present a comprehensive modeling approach that should be useful in the examination of the kinetics of drugs during continuous ambulatory peritoneal dialysis. Clinical Pharmacology and Therapeutics (1986) 40, 209–218; doi:10.1038/clpt.1986.165
Use of SF6 to label drilling air in unsaturated, fractured rock studies: risk of over-purging

Abstract Sulfur hexafluoride was injected as a tracer gas into the air stream during air-drilling of a borehole in the unsaturated zone of a partially-welded, fractured tuff at Apache Leap, Arizona. One-meter intervals were later isolated at multiple depths and pumped to purge drilling air from each interval. The volume of air purged (at 1 atm, 20 °C), ranged from a low of 0.3 m 3 in an unfractured interval, to a high of 252 m 3 in a highly fractured interval. The concentration of SF 6 remained high throughout the purge in all intervals and often increased over time. Measurements of δ 13 C, 14 C and CO 2 concentration indicated that atmospheric air was eventually drawn into several of the intervals in spite of the fact that SF 6 concentrations remained high. Possible explanations include mixing of atmospheric air drawn through fractures with partially-purged matrix air, and delayed removal of SF 6 relative to atmospheric gases due to adsorption of SF 6 within the tuff matrix, dissolution into pore water, or diffusion from dead-end pores with restricted openings. In this system, following a long delay between drilling and purging, it was found that the risk of contamination from surface air by over-purging was substantially greater than the risk of contamination from residual drilling air by under-purging.
First Observations of Mercury's Plasma Mantle by MESSENGER†

We present the first observations of Mercury's plasma mantle, a primary region for solar wind entry into the planetary magnetosphere, located in the high-latitude magnetotail. MESSENGER observations from two orbits on 10 November 2012 have been analyzed. The main plasma mantle features are (1) a steady decrease in proton density as MESSENGER moved deeper into the magnetotail; (2) frequent flux transfer events throughout the magnetosheath and into the magnetotail, suggesting that these events are the primary source for solar wind plasma injection; (3) a diamagnetic depression, due to the presence of plasma, as pressure balance is maintained; and (4) a clear proton velocity dispersion, resulting from lower-energy protons being transported deep into the magnetosphere as higher-energy protons escape downtail. From these velocity dispersions we infer cross-magnetosphere electric potentials of 23 kV and 29 kV, consistent with estimates determined from measurements of magnetopause reconnection rate and tail loading and unloading events.
High Dimensional Stochastic Simulation and Electric Ship Models

Determination of statistical moments requires the numerical computation of integrals, but as the number of random dimensions increases, computational cost grows dramatically. There is great interest in the large scale complex systems encountered in the all-electric ship, and to deal with the large dimension, we present the sparse grid technique based on Smolyak's algorithm for evaluating mid-dimensional integrals. We compare its performance with collocation (full grid) and Monte Carlo methods, first focusing on a now standard package of six test integrals proposed by Genz. We then apply these methods to a validated electric ship model to compute mean and variance behaviors, given variation in physical parameters, both individually and in ranked sets.
SIP-RLTS: An RFID Location Tracking System Based on SIP

Radio Frequency Identification (RFID) technology has recently being favorably considered as a cost-effective alternative for indoor location tracking. However, most current implementations use active tags and conventional middleware, which are more expensive, complicate to use, and may not work with other pervasive devices such as IP Multimedia systems or cell phones. In this paper, we propose an RFDD-enabled location tracking system, SIP-RLTS, based on Session Initiation Protocol (SIP). Our proposed solution can be used for both Push and Pull location tracking modes and can be used with either active or passive tags. The use of SIP infrastructure, coupled with the proposed location-oriented middleware extension, Ontology infrastructure and semantic integration, making SIP-RLTS a more cost-effective solution for the next generation communication services.
Codon-Optimized Fluorescent Proteins Designed for Expression in Low-GC Gram-Positive Bacteria

Fluorescent proteins have wide applications in biology. However, not all of these proteins are properly expressed in bacteria, especially if the codon usage and genomic GC content of the host organism are not ideal for high expression. In this study, we analyzed the DNA sequences of multiple fluorescent protein genes with respect to codons and GC content and compared them to a low-GC gram-positive bacterium, Bacillus anthracis. We found high discrepancies for cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), and the photoactivatable green fluorescent protein (PAGFP), but not GFP, with regard to GC content and codon usage. Concomitantly, when the proteins were expressed in B. anthracis, CFP- and YFP-derived fluorescence was undetectable microscopically, a phenomenon caused not by lack of gene transcription or degradation of the proteins but by lack of protein expression. To improve expression in bacteria with low genomic GC contents, we synthesized a codon-optimized gfp and constructed optimized photoactivatable pagfp, cfp, and yfp, which were in contrast to nonoptimized genes highly expressed in B. anthracis and in another low-GC gram-positive bacterium, Staphylococcus aureus. Using optimized GFP as a reporter, we were able to monitor the activity of the protective antigen promoter of B. anthracis and confirm its dependence on bicarbonate and regulators present on virulence plasmid pXO1.
The Sums of Alternating Series of Odd Powers of the Reciprocals of Odd Positive Integers

This paper is an extension of a recent work done by the author [4] and here the sums of alternating series of odd powers (up to fifteen) of the reciprocals of odd positive integers are computed. Following this method, the sum of the series of any higher power could be calculated. In the process of computing these sums, the sums of the series of even powers of reciprocals of odd positive integers have been reestablished and enabled the author to compute the values of Riemann’s zeta function for even positive integers.
Leukocyte adhesion: an exquisite balance of hydrodynamic and molecular forces.

Leukocyte adhesion to the vascular endothelium involves a disruptive force exerted on the leukocyte by the flow of the blood and an adhesive force that forms at the leukocyte-endothelial interface. The relative strengths of these two competing forces govern leukocyte adhesion.
A three-dimensional model for analyzing the effects of salmon redds on hyporheic exchange and egg pocket habitat

A three-dimensional fluid dynamics model is developed to capture the spatial complexity of the effects of salmon redds on channel hydraulics, hyporheic exchange, and egg pocket habitat. We use the ...
An Analysis of U.S. Road Fatalities per Population: Changes by Age From 1958 to 2008

Objective: This article presents a time-series analysis of changes in road safety in the United States from a public-health point of view. Method: A 50-year period was examined, from 1958 to 2008. The emphasis was on the changes by decades in fatalities per population across different age groups. Results: First, from 1958 to 2008, the overall fatality rate per population decreased by 40 percent. Second, the decrease in the rate was age dependent (with the largest decreases for the youngest and the oldest, and the smallest decreases for the middle-aged). Third, the overall fatality rate increased from 1958 to 1968, but it decreased for each of the 4 following decades. Fourth, the changes in the rate for each decade were age dependent. Fifth, the patterns of these age-dependent changes varied across the decades. Conclusions: Examples of interventions that are likely to have age-dependent effects consistent with the obtained differential age changes in the fatality rate are discussed. However, other interven...
Geoscience salaries up by 10.8

According to a recent salary survey of over 4000 scientists in all fields by Research and Development (March 1984) geoscientists ranked fourth place for 1984. Mathematics, aeronautical engineering, and metallurgy had higher median salaries, but the discipline of geoscience had a higher median salary than that of physics, chemical engineering, mechanical engineering, electrical engineering, ceramics, chemistry, industrial engineering, biology, and other fields of research and development. The 1984 median salary for geoscientists was $40,950, up from the median value by 10.8%. In 1983, geoscience was ranked in ninth place. The geoscientist profile for 1984 was not unusual. The median age was 47.5 years, and the median years of experience was 18. Geoscientists are the best educated. Eighty-two percent of the geoscientists polled had advanced degrees beyond the bachelor's degree. Fifty-six percent of the geoscientists had the Ph.D. degree.
Estimating motion of constant acceleration from image sequences

Presents a model-based algorithm for estimating motion from monocular image sequences. The authors first present a two-view motion algorithm and then extend it to multiple views. The two-view algorithm requires generally 6 pairs of point correspondences to give unique solution of the motion parameters. However, when the used points lie on a Maybank quadric, the algorithm requires 7 pairs of point correspondences to give double solutions. Object-centered motion representations and a motion model of constant acceleration are used to estimate motion parameters from long image sequences. The algorithm guarantees globally optimal solution. Since the algorithm does not involve structure parameters, it contains the least number of unknowns and is hence more efficient and robust than the existing ones. Experimental results with real image data are presented. The same method can be applied to solve for motions described by second or higher orders of polynomials. >
Novel applications of the Onyx liquid embolic system: illustrative review of treating peripheral vascular, genitourinary, and gastrointestinal pathologies

indications and contraindications for lymphangiography.2. Understand the roles of lymphoscintigraphy and lymphangiography and how the two studies can combine to further enhance the quality of patient care. Background: Background: Previously the primary imaging technique to evaluate lymph nodes for cancer and infection, lymphangiography has been overtaken by cross-sectional and nuclear imaging. It however remains important in patients with chylous ascites and/or effusions for surgical planning or direct percutanous intervention. Clinical Findings/Procedure Details: Technique: Traditional technique involves four basic steps. 1) Injection of blue dye in the web spaces of the hands or feet. 2) Cutdown and cannulation of a blue lymphatic duct. 3) Slow injection of fat-based dye. 4) Periodic fluoroscopy, radiography and/or CT. Intranodal technique involves three basic steps. 1) Ultrasoundguided puncture of a groin lymph node. 2) Slow injection of fatbased dye. 3) Periodic fluoroscopy, radiography and/or CT. Complications: Severe complications are extremely rare. Minor complications include dye reaction and infection at the injection site. Conclusion and/or Teaching Points:
The Effects of the Moms and Teens for Safe Dates Program on Dating Abuse: a Conditional Process Analysis

Moms and Teens for Safe Dates (MTSD) is a dating abuse (DA) prevention program for teens exposed to domestic violence. In a randomized controlled trial (RCT), MTSD prevented certain types of DA victimization (psychological and physical) and perpetration (psychological and cyber) among teens with higher, but not lower, exposure to domestic violence. We built on these findings by using moderated mediation analysis to examine whether level of teen exposure to domestic violence conditioned the indirect effects of MTSD on these types of DA through targeted mediators. MTSD consisted of six mailed activity booklets. Mothers who had been former victims of domestic violence delivered the program to their teens. Mother and teen pairs were recruited into the RCT through community advertising and completed baseline and 6-month follow-up interviews (N = 277 pairs). As expected, MTSD had significant favorable effects for teens with higher but not lower exposure to domestic violence on several mediators that guided program content, including teen conflict management skills and mother-perceived severity of DA, self-efficacy for enacting DA prevention efforts, and comfort in communicating with her teen. MTSD had significant main effects on other mediators including teen feeling of family closeness and cohesion and mother-perceived susceptibility of her teen to DA. As expected, all significant indirect effects of MTSD on DA outcomes through mediators were for teens with higher exposure to domestic violence. Findings have implications for developing DA victimization and perpetration prevention programs for teens with high exposure to domestic violence.
A theory of competitive analysis for distributed algorithms

We introduce a theory of competitive analysis for distributed algorithms. The first steps in this direction were made in the seminal papers of Y. Bartal et al. (1992), and of B. Awerbuch et al. (1992), in the context of data management and job scheduling. In these papers, as well as in other subsequent sequent work, the cost of a distributed algorithm is compared to the cost of an optimal global-control algorithm. In this paper we introduce a more refined notion of competitiveness for distributed algorithms, one that reflects the performance of distributed algorithms more accurately. In particular, our theory allows one to compare the cost of a distributed on-line algorithm to the cost of an optimal distributed algorithm. We demonstrate our method by studying the cooperative collect primitive, first abstracted by M. Saks, N. Shavit, and H. Woll (1991). We provide the first algorithms that allow processes to cooperate to finish their work in fewer steps. Specifically, we present two algorithms (with different strengths), and provide a competitive analysis for each one. >
Public perception of and reaction to multi‐channel cable television service

Cable subscribers and nonsubscribers were compared on a variety of behavioral and attitudinal measures across time. The anticipation was that experience with cable television service involving imported broadcast channels, cable networks, pay cable, and local origination would lead to a more positive evaluation with time. The opposite results were found.
Does an Increase in the Medicaid Reimbursement Rate Improve Nursing Home Quality

Objectives Numerous studies have documented poor nursing home quality over the last 3 decades. Previous research has questioned the effectiveness of Medicaid reimbursement policy in improving quality in the presence of certificate-of-need (CON) and construction moratoria regulation. This study evaluated how the Medicaid reimbursement rate may influence a home's decision to provide quality under CON and moratoria. Methods Linking national data from the On-Line Survey, Certification, and Reporting system, the Area Resource File, and aggregate reimbursement information, the author examined the effect of Medicaid reimbursement on a range of quality measures in the context of CON and moratoria. Results An increase in Medicaid reimbursement improved quality as measured by professional staffing, but there was not a statistically significant effect when quality was measured by nonprofessional staffing, various procedural measures, or regulatory deficiencies. However, this study did not support previous research showing a negative effect of Medicaid reimbursement on nursing home quality in the context of CON laws. Discussion This study supports recent trends suggesting that nursing home CON laws may be lessening in importance for the nursing home market. Nevertheless, further work is necessary to determine the quality returns to increased Medicaid reimbursement.