cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis, characterization, and X-ray crystal structure of the octabromodiosmate(III) salt [(C5Me4H)2OsBr]2[Os2Br8] and its conversion to [(C5Me4H)2OsBr][Os2HBr4(cod)2]

Abstract Treatment of hexabromoosmic acid, H 2 OsBr 6 , with 4 equiv. of tetramethylcyclopentadiene (C 5 Me 4 H 2 ) in tert -butanol at reflux for 8 h affords the unusual salt [(C 5 Me 4 H) 2 OsBr] 2 [Os 2 Br 8 ], 1 , which is the bis(tetramethylcyclopentadienyl)bromoosmocinium(IV) salt of the octabromodiosmate(III) dianion. The brown color of the salt suggests that the anion adopts an eclipsed conformation ( D 4 h symmetry) and this conclusion has been confirmed by a single-crystal X-ray diffraction experiment. The X-ray crystal structure indicates that the osmium atoms in the [ Os 2 Br 8 2 - ] anion are disordered over two sites. The bromine atoms show no evidence of disorder and are disposed in a quasi-cubic arrangement; the two Os–Os vectors are almost exactly orthogonal to each other and each vector points toward a different pair of opposite square faces of the Br 8 cube. The Os–Os bond distances are 2.219(5) and 2.229(1) A; the average Os–Br distance in the anion is 2.417(2) A. Treatment of [(C 5 Me 4 H) 2 OsBr] 2 [Os 2 Br 8 ] with excess 1,5-cyclooctadiene in ethanol at gentle reflux for 3 h affords [(C 5 Me 4 H) 2 OsBr][Os 2 HBr 4 (cod) 2 ], 2 . An X-ray crystallographic study was carried out on a sample in which the cation was a mixture of [(C 5 Me 4 H) 2 OsBr + ] and [(C 5 Me 4 H) 2 OsH + ]. The results demonstrate that the anion adopts a confacial bioctahedral structure in which the hydride ligand and two bromides bridge between the two osmium centers. The C C bonds of the cod ligands are trans to the bridging bromide groups. The Os–Os bond distance in the anion is 2.874(1) A. The average Os–Br distance is 2.596(2) A for the bridging bromides and 2.565(2) A for the terminal bromides. Compound 2 is the first example of an anionic diosmium complex containing a bridging hydride. The reaction of 1 with cod also results in the formation of bis(tetramethylcyclopentadienyl)osmocene, (C 5 Me 4 H) 2 Os, 3 , which has been isolated and characterized. Treatment of (C 5 Me 4 H) 2 Os with 1.0 equiv. of HBF 4 · Et 2 O affords the osmocinium salt [(C 5 Me 4 H) 2 OsH][BF 4 ].
Testing the role of chain connectivity on the stability and structure of dihydrofolate reductase from E. coli: fragment complementation and circular permutation reveal stable, alternatively folded forms.

The effects of chain cleavage and circular permutation on the structure, stability, and activity of dihydrofolate reductase (DHFR) from Escherichia coli were investigated by various spectroscopic and biochemical methods. Cleavage of the backbone after position 86 resulted in two fragments, {1–86} and {87–159}, each of which are poorly structured and enzymatically inactive. When combined in a 1 : 1 molar ratio, however, the fragments formed a high-affinity (Ka = 2.6 × 107 M−1) complex that displays a weakly cooperative urea-induced unfolding transition at micromolar concentrations. The retention of about 15% of the enzymatic activity of full-length DHFR is surprising, considering that the secondary structure in the complex is substantially reduced from its wild-type counterpart. In contrast, a circularly permuted form with its N-terminus at position 86 has similar overall stability to full-length DHFR, about 50% of its activity, substantial secondary structure, altered side-chain packing in the adenosine binding domain, and unfolds via an equilibrium intermediate not observed in the wild-type protein. After addition of ligand or the tight-binding inhibitor methotrexate, both the fragment complex and the circular permutant adopt more native-like secondary and tertiary structures. These results show that changes in the backbone connectivity can produce alternatively folded forms and highlight the importance of protein-ligand interactions in stabilizing the active site architecture of DHFR.
A communication requirement within a biochemistry course

intent on exposing students to more and more “facts” that written and oral components are rarely incorporated. At Clemson University there is a campus-wide effort to incorporate written and oral components into all courses. which has drawn the attention of Time magazine [l]. Below
Co-movements of major European community stock markets: A vector autoregression analysis

Since 1980, as most advanced economies deregulated their capital markets, removed barriers to international investments, and improved the accessibility to information, investors in many countries have adopted a global view. These trends are especially pronounced in Europe, where European Community (EC) countries have embarked on a process of unifying their economies and their financial markets. The Maastricht treaty, which was agreed to by EC leaders in December 1991, established the steps toward a currency union and closer political integration. Moreover, by 1996, the EC Investment Services Directive will allow stockbrokers to operate across national borders without the need to establish local subsidiaries. Global trends notwithstanding, European financial intermediaries, investors, and corporations are national rather than pan-European in character. There are substantial differences among EC countries in the regulation of national securities markets, taxes, corporate laws, and accounting practices. Barriers to crossborder investments, e.g., pension funds, remain. The purpose of this study is to examine the dynamic linkages among the eight major EC stock markets. The interdependence among national stock markets has been the subject of several recent papers (Schollhammer & Sand, 1985, 1987; Eun & Shim, 1989; Merit & Merit, 1989; Jeon & Von Furstenberg, 1990; Von Furstenberg & Jeon, 1989; Koch & Koch, 1991). These studies were motivated by growing recognition of the benefits of international portfolio diversification (e.g., Grubel, 1968; Grubel & Fadner, 1971; Levy & Samat, 1970; Agmon, 1972) and the international propagation of the October 1987 crash (e.g., Malliaris & Urrutia, 1992). None of these studies solely focused on Europe.
Pedestrian Visibility Under Automobile Low-Beam Headlight Illumination: With and Without Headlight Covers:

Pedestrians and bicyclists are the most vulnerable of all participants in traffic. Their safety at night should be a priority for headlamp designers, rule-making agencies, and consumers alike. A disturbing trend—the use of very dark aftermarket headlamp covers on vehicle headlamps—is emerging. This trend is observed primarily in sports cars owned by young drivers. These dark headlamp covers, often referred to as blackouts, serve no real purpose other than that of supposedly enhancing vehicle appearance. For a driver using such headlamp covers at night, it may appear as though the overall visibility is not much affected. However, this perception is misleading and wrong, as will be clearly demonstrated. The objective was to quantify the detrimental effects dark headlamp covers have on pedestrian visibility. To do so, detection distances were obtained in the field using 15 observers who were approaching stationary pedestrian mockups. The independent variables were pedestrian size (child, adult), diffuse clot...
The rotifer contribution to the diet of Eudiaptomus gracilis (G. O. Sars, 1863) (Copepoda, Calanoida)

We studied potentially omnivorous feeding of the common limnetic calanoid copepod Eudiaptomus gracilis using feeding experiments with subsequent gut content analysis. Feeding experiments performed with a laboratory culture of the rotifer Brachionus calyciflorus established a daily feeding rate reaching up to 9.8 rotifers per day when a rotifer-only diet was offered. Addition of algae (Chlamydomonas sp.) to the calanoid diet decreased the ingestion rate of rotifers to near 0. Yet, gut content analysis regularly (though not very frequently) revealed the remains of a rotifer, B. calyciflorus, in the digestive tract of an E. gracilis. We thus proved the ability of E. gracilis to feed on rotifers, even when these were offered in a diet mixed with algae.
On Shaky Ground: The Making of Risk in Bogotá

How does risk become a technique for governing the future of cities and urban life? Using genealogical and ethnographic methods, this paper tracks the emergence of risk management in Bogota, Colombia, from its initial institutionalization to its ongoing implementation in governmental practice. Its specific focus is the invention of the ‘zone of high risk’ in Bogota and the everyday work performed by the officials responsible for determining the likelihood of landslide in these areas. It addresses the ongoing formation of techniques of urban planning and governance and the active relationship between urban populations and environments and emerging forms of political authority and technical expertise. Ultimately, it reveals that techniques of risk management are made and remade as experts and nonexperts grapple with the imperative to bring heterogeneous assemblages of people and things into an unfolding technopolitical domain.
The Clouds: Aristophanic comedy and democratic education

(1997). The Clouds: Aristophanic comedy and democratic education. Rhetoric Society Quarterly: Vol. 27, No. 4, pp. 25-46.
Robust Adaptive Control of Underwater Vehicles with Biologically Inspired Vortex Ring Thrusters

Abstract A novel underwater thruster was designed to provide quantized level of thrusts for underwater vehicle maneuvering with a minimal effect on the drag profile of the vehicle. The design was inspired by the efficient and agile locomotion mechanism in squid and jellyfish, which is characterized by formation of vortex rings from pulsatile jets. There have been several successful implementations of the device on a series of autonomous underwater vehicles in our group. In this paper, a robust adaptive control algorithm is formulated for future vehicles with new, more compact thrusters of this type. Control strategy for motion in 6 degrees of freedom, together with corresponding force allocation method is developed and is tested in simulation, where an asymptotic position and velocity tracking result is obtained.
The evaluation of numerical techniques for solution of stiff ordinary differential equations arising from chemical kinetic problems

Abstract Ordinary differential equations with widely scattered eigenvalues (stiff O.D.E.'s) occur often in the studies of reaction network problems. Five numerical methods, including two methods based on Backward differentiation formulas, a modified Runge-Kutta-Fehlberg method, a method based on PECE Adams formulas, and an improved semi-implicit Euler method are evaluated by comparing their performance when applied to test systems. The test systems represent different combinations of linearity and nonlinearity, small and large dimension, real and complex eigenvalues, and slightly stiff and very stiff problems. The relative merits and dificiencies of the methods are discussed.
Why nondominant hand movements cause bilateral cortical activation in emission imaging.

To the Editor: The contribution of Kato et al1 contains important laterality related data. But the respected authors resort to undocumented and unwarranted assertions from the literature that one must address in order to arrive at a cogent interpretation of their data. They used the 1963 article of Nyberg-Hensen and Rinvik2 to support the existence of 10% to 15% uncrossed pyramidal fibers in humans. This article, which is often used for this very purpose, states that “the only safe conclusion to be drawn from the available data is that there may probably be considerable variation with regard to the proportion of crossed and uncrossed corticospinal fibers in man,” never offering or referring to such anatomical documentation in humans as asserted by Kato et al. On the other hand, the current techniques of cortical mapping with sufficient temporal resolution employing electroencephalography, magnetoencephalography, and transcranial magnetic stimulation (TMS) all have demonstrated sequential activation of the major followed by the minor hemisphere on moving the nondominant hand (see below). This temporal feature of bimanual coordination in humans translates into such daily life experiences as (1)) the double-click heard with snapping one’s fingers of both hands simultaneously (Derakhshan, unpublished data), (2) the melody lead of the right hand in piano playing3 (known to musicologists for 160 years), and (3) the precedence of the bowing hand to the fingering in violin playing, recently documented by Wiesendanger et al.4 This callosally mediated delay of 10 to 40 ms involving the nondominant hand requires an anatomical explanation not forthcoming from the (unmodified) …
Injectable biodegradable polymer composites based on poly(propylene fumarate) crosslinked with poly(ethylene glycol)-dimethacrylate

New injectable, in situ crosslinkable biodegradable polymer composites were investigated consisting of poly(propylene fumarate) (PPF), poly(ethylene glycol)-dimethacrylate (PEG-DMA), and beta-tricalcium phosphate (beta-TCP). We examined the effects of the PEG-DMA/PPF double-bond ratio and beta-TCP content on the crosslinking characteristics of the composites including the maximum crosslinking temperature and the gel point, as well as the properties of the crosslinked composites such as the compressive strength and modulus, and the water-holding capacity. The maximum crosslinking temperature was constant averaging 39.7 degrees C for the composite formulations tested. The gel points varied from 8.0 +/- 1.0 to 12.6 +/- 2.5 min and were not affected by the relative amounts of PEG-DMA. The compressive strength at yield of PEG-DMA/PPF composites without beta-TCP increased from 5.9 +/- 1.0 to 11.2 +/- 2.2 MPa as the double-bond ratio of PEG-DMA/PPF increased from 0.38 to 1.88. An increase in compressive modulus was also observed from 30.2 +/- 3.5 to 58.4 +/- 6.2 MPa for the same range of the PEG-DMA/PPF double-bond ratio. Also, the addition of beta-TCP (33 wt%) enhanced the mechanical properties of all composites. The equilibrium water content of networks without beta-TCP increased from 21.7 +/- 0.2 to 30.6 +/- 0.2% for a double-bond ratio of PEG-DMA/PPF ranging from 0.38 to 1.88. However, the mechanical properties of the swollen composites under compression were smaller than the dry ones. These data demonstrate the feasibility of fabricating injectable biodegradable polymer composites with engineered mechanical properties for orthopedic tissue engineering.
ABSORPTION OF SO2 AND H2S IN SMALL-SCALE VENTURI SCRUBBERS

Small-scale venturi scrubbers having geometries of typical large-scale units were constructed from glass and were operated in a laboratory system. Carrier gas streams consisting of air or nitrogen and up to 30% (by volume) CO2 were mixed with SO2 or H2S to give SO2 or H2S concentrations in the range of 1890–4400 ppm. These gas mixtures were then scrubbed in the Venturis using various injected liquids (plain water, NaOH solutions, NH4OH solutions, and NaOH/NaHCO3 solutions) at L/G ratios of 0.0004–0.0040 m3 liquid per standard (1 atm, 60°F)m3 of gas (3–30 gallons liquid per 1000 standard ft3 of gas). Absorption percentages for SO2 and H2S were determined as functions of the L/G ratio, initial liquid pH, and liquid composition. The effects of venturi throat length, gas velocity, and the presence of CO2 in the gas stream were also determined.
Quaternary phase relations near YBa2Cu3O6+x at 850°C in reduced oxygen pressures

Abstract The quatenary phase relations near YBa 2 Cu 3 O 6+ x at 850°C were determined by oxygen coulometric titration and microanalysis. The phase relations change markedly as the oxygen pressure decreases, due primarily to the formation of a liquid phase and a reduced oxide, BaCu 2 O 2 . Nine invariant reactions were discovered, including decomposition of YBa 2 Cu 3 O 6+ x into Y 2 BaCuO 5 , BaCu 2 O 2 and YBa 3 Cu 2 O 6+ y . The lower limit of oxygen partial pressure at which pure YBa 2 Cu 3 O 6+ x is stable is 4.0×10 −4 atm O 2 at 850°C; the lower limit increases in the presence of BaCuO 2 and Cu 2 O impurities. These results indicate that the temperatures used for single crystal growth of YBa 2 Cu 3 O 6+ x could be lowered by using reduced oxygen pressures or, alternatively, that constant temperature crystal growth could be induced by increasing the oxygen partial pressure.
Statistical and computational models of the visual world paradigm: Growth curves and individual differences

Time course estimates from eye tracking during spoken language processing (the “visual world paradigm”, or VWP) have enabled progress on debates regarding fine-grained details of activation and competition over time. There are, however, three gaps in current analyses of VWP data: consideration of time in a statistically rigorous manner, quantification of individual differences, and distinguishing linguistic effects from non-linguistic effects. To address these gaps, we have developed an approach combining statistical and computational modeling. The statistical approach (growth curve analysis, a technique explicitly designed to assess change over time at group and individual levels) provides a rigorous means of analyzing time course data. We introduce the method and its application to VWP data. We also demonstrate the potential for assessing whether differences in group or individual data are best explained by linguistic processing or decisional aspects of VWP tasks through comparison of growth curve analyses and computational modeling, and discuss the potential benefits for studying typical and atypical language processing.
MRI with an atomic magnetometer suitable for practical imaging applications.

Abstract Conventionally implemented MRI is performed in a strong magnetic field, typically >1 T. The high fields, however, can lead to many limitations. To overcome these limitations, ultra-low field (ULF) [or microtesla] MRI systems have been proposed and implemented. To-date such systems rely on low-Tc Superconducting Quantum Interference Devices (SQUIDs) leading to the requirement of cryogens. In this letter, we report ULF–MRI obtained with a non-cryogenic atomic magnetometer. This demonstration creates opportunities for developing inexpensive and widely applicable MRI scanners.
Effect of noise on the performance of optical 3R regeneration

The regeneration of optical data signals is an important requirement of WDM and OTDM networking schemes. All-optical regenerators based on cross phase modulation schemes currently require complicated systems of several optical components and modules together with complex control. Here we demonstrate an optical 3R regeneration in a single DFB laser. The key to this regeneration process is to gain switch the DFB laser with a clock signal extracted from the data signal in order to retime the converted signal. A data signal at 10Gbits/s sent to 80Km in a SMF with poor Q is reamplified, retimed and reshaped by this laser. However the uncorrelated jitter (amplitude and phase noise) primarily present due to the spontaneous emission in the directly modulated transmitting laser as well as in the gain switched DFB laser (Regenerator) can very easily distort the whole regeneration process. In this paper we propose a systematic approach to tackle this problem to effectively enhance the performance of optical regenerator. An improvement of orders of magnitude in BER measurement can be achieved. The proposed approach results in a regenerated signal whose optical power, Q factor and extinction ratio are considerably improved by the regeneration process.
Formation of the condensate in a dilute Bose gas.

We examine the time evolution of a weakly interacting Bose gas in the course of the Bose-Einstein phase transition and show that, in contrast with previous claims in the literature, the relevant time scale for the appearance of the condensate is finite and, under the conditions we consider, of O(ħ/kBTc), which is very small compared to the characteristic lifetime of the system due to inelastic collisions in the gas.
Intramolecular dG.dG.dC triplex detected in Escherichia coli cells.

The formation of an intramolecular dG·dG·dC triplex in Escherichia coli cells is demonstrated at single-base resolution. The intramolecular dG·dG·dC triplex structure was probed in situ for E. coli cells containing plasmid DNAs with varying lengths of poly(dG)·poly(dC) tracts employing chloroacetaldehyde. This chemical probe reacts specifically with unpaired DNA bases. The triplex structure formed with the poly(dG)·poly(dC) tracts of 35 and 44 base-pairs, but not with 25 base-pairs. The triplex was detected only one to two hours after the chloramphenicol treatment: the period at which the extracted plasmid DNA revealed the maximal superhelical density.
Transfer-pricing mechanisms: An experimental investigation

Abstract This study evaluates, in a laboratory setting, the performance of the Ronen and McKinney (1970) and the Ronen (1992) transfer-pricing schemes. Both mechanisms possess, in theory, the property of inducing efficient production and truth-telling, while decision-making autonomy is maintained. The Ronen/McKinney scheme, however, allows for multiple Nash equilibria and if the divisions' managers coordinate their messages they are expected to exploit the mechanism at the expense of the overall profitability of the firm. The Ronen (1992) scheme was designed to prevent this; towards this end, a penalty factor was incorporated into the original Ronen/McKinney scheme to make truth-telling and optimal production a unique equilibrium. The basic results are that under the Ronen/McKinney scheme and with coordination of messages being allowed, subjects collude and earn significantly higher profits than amounts implied by the overall optimal solution. Without the penalty factor, subjects seemed not to converge towards the efficient level of transacting at the end of the experiment. It is not clear whether with additional trials such conversion would have occurred. The inclusion of the penalty factor, however, eliminated the collusive behaviour. In fact, most of the pairs implementing the Ronen mechanism reached the efficiency predicted by the theory whether or not coordination of messages was allowed.
Experiencing the City: Experiential Learning in Urban Environments

Both history internships and urban history courses that offer place-based learning experiences provide students with an introduction to the role that historical scholarship can play in the everyday...
Optical properties of rare-gas fluoride dimers and trimers dissolved in liquid rare gases

Cryogenic rare-gas fluorine solutions are studied with optical excitation provided by excimer laser radiation at 193, 248, and 351 nm. Fluorescences corresponding to dimer [$\mathrm{Kr}{\mathrm{F}}^{*}(D\frac{1}{2}\ensuremath{\rightarrow}X\frac{1}{2})$, $\mathrm{Xe}{\mathrm{F}}^{*}(D\frac{1}{2}\ensuremath{\rightarrow}X\frac{1}{2})$, $\mathrm{Xe}{\mathrm{F}}^{*}(B\frac{1}{2}\ensuremath{\rightarrow}X\frac{1}{2})$, $\mathrm{Xe}{\mathrm{F}}^{*}(C\frac{3}{2}\ensuremath{\rightarrow}A\frac{3}{2})$] and trimer (${\mathrm{Ar}}_{2}$${\mathrm{F}}^{*}$, ${\mathrm{Kr}}_{2}$${\mathrm{F}}^{*}$, ${\mathrm{Xe}}_{2}$${\mathrm{F}}^{*}$) transitions are detected in several rare-gas liquid hosts. All of the emission bands detected exhibit red shifts with respect to the gas-phase spectra. With the exception of the $\mathrm{Xe}{\mathrm{F}}^{*}(C\ensuremath{\rightarrow}A)$, ${\mathrm{Kr}}_{2}$${\mathrm{F}}^{*}$, and ${\mathrm{Xe}}_{2}$${\mathrm{F}}^{*}$ bands, the shifts increase in magnitude with an increase of the atomic number of the host.
Evaluating a Psychology Graduate Student Peer Mentoring Program.

Research on mentoring outcomes and characteristics of various types of mentoring programs in different settings is limited. The present study sampled 39 graduate students at a small Midwestern university to evaluate peer mentoring in a graduate school setting. Mentoring function and outcome relationships as well as program characteristics were explored. As expected, mentoring functions were highly correlated with various outcomes. Results indicated psychosocial assistance, networking help, and relational outcomes were reported most among participants. Interestingly, pair compatibility and mentor preparation were not found to be essential program characteristics. Program recommendations and future research are discussed.
The role of federal regulations in assuring research integrity.

The federal government has a proper interest in research integrity. Regulations have had effects on scientists and institutions; some appear to have been beneficial, such as recent educational efforts; others have augmented bureaucracy and sowed divisiveness. The federal oversight bureaucracy should be subject to the sunset provision. Participation by the community is essential to the development of effective regulations, but ethical issues should be dealt with by professional standards, not laws. It is argued that the scientific community had begun to respond to public concerns when change was accelerated by regulation, and that change from within is most effective.
Sunitinib malate is active against human urothelial carcinoma and enhances the activity of cisplatin in a preclinical model.

Abstract Purpose Sunitinib malate (Pfizer, Inc.) is a multitargeted kinase inhibitor that inhibits vascular endothelial growth factor (VEGF) receptor (R)-1, 2 and 3, platelet-derived growth factor receptors (PDGFR)-α and β, Flt3, RET, and Kit. Angiogenesis and VEGF expression correlate with poor outcomes in human urothelial carcinoma. We designed a preclinical study to examine the efficacy of sunitinib alone and in combination with cisplatin against human urothelial carcinoma. Design The in vitro activities of sunitinib and cisplatin alone and in combination were determined against human urothelial carcinoma cell lines, TCC-SUP and 5637. Antitumor activities were also determined in vivo against murine subcutaneous 5637 xenografts. Immunohistochemistry (IHC) was performed to detect VEGFR2 and Kit, and modulation of proliferation, apoptosis, and angiogenesis. Results Both cell lines expressed VEGFR2, but did not express Kit. Sunitinib displayed activity against both cell lines in vitro at low micromolar concentrations, which are not attainable in vivo, and was synergistic with cisplatin. Activity was observed for sunitinib at 20 and 40 mg/kg orally once daily for 4 weeks, which attains low nanomolar concentrations in vivo against murine 5637 xenografts. Sunitinib 20 mg/kg/d in combination with cisplatin 4 mg/kg/wk intraperitoneally induced tumor regression compared to no therapy ( P P = 0.06). Cisplatin, sunitinib, and combination treated tumors displayed significantly reduced ki-67 expression compared with control untreated tumors, and the difference was also statistically significant for the combination compared with cisplatin. Cleaved caspase-3 expression was significantly higher for sunitinib single agent and combination therapy compared with untreated controls, and for combination therapy compared with cisplatin alone. CD31 expression was diminished for both single agents and combination therapy compared with untreated tumors. Conclusions Sunitinib is preclinically active against urothelial carcinoma, and enhances the activity of cisplatin probably by targeting the stroma.
Generation and investigation of airborne silver nanoparticles with specific size and morphology by homogeneous nucleation, coagulation and sintering

Abstract An aerosol generation facility has been characterized to produce well-defined silver nanoparticles for use as a test aerosol when evaluating instrument response to different particle morphologies within a range of sizes. The generator consists of two in-series laminar tube furnaces to produce and subsequently sinter particles, and is capable of generating spherical or agglomerated fractal-like silver particles, with corresponding projected surface (two-dimensional) fractal dimensions from 1.58 to 1.94. The morphologies of generated particles as well as size distributions at different sintering temperatures were characterized using a transmission electron microscope (TEM) and a scanning mobility particle sizer (SMPS). Mean diameters measured were significantly reduced for sintering temperatures from 100 to 300 ∘ C , but showed little variation for sintering temperatures above 500 ∘ C . TEM analysis indicated that this phenomenon was caused by sintering, followed by partial and complete coalescence of fractal-like agglomerates into spheres. Agglomerate restructuring from classical completely sintered agglomerates ( 500 ∘ C ) to spherical particles ( 700 ∘ C ) did not lead to a change in the particle mobility size distribution. The temperature at which complete sintering occurred was higher than that predicted by theory, but was in reasonable agreement with previously published experimental data. For monodisperse particles in the size range from 20 to 100 nm, a simple exponential model related sintering temperature to the diameter of coalesced spherical particles.
3-D High-Lift Flow-Physics Experiment - Transition Measurements

§An analysis of the flow state on a trapezoidal wing model from the NASA 3-D High Lift Flow Physics Experiment is presented. The objective of the experiment was to characterize the flow over a non-proprietary semi-span three-element high-lift configuration to aid in assessing the state of the art in the computation of three-dimensional high-lift flows. Surface pressures and hot-film sensors are used to determine the flow conditions on the slat, main, and flap. The locations of the attachments lines and the values of the attachment line Reynolds number are estimated based on the model surface pressures. Data from the hotfilms are used to determine if the flow is laminar, transitional, or turbulent by examining the hot-film time histories, statistics, and frequency spectra. Nomenclature
The depressive illnesses: Their diagnosis and treatment

0 NE of the most ubiquitous phenomena of man’s affective experiences is the disorder of mood called depression. Depression is a normal emotional response to a loss, such as a loss of a close interpersonal relationship, of prestige and position, of finances, or similar experiences. In addition depression is probably the most common of psychiatric symptoms, being associated with many psychiatric conditions and various types of physical disease. The symptom of depression can occur at any age, although it is difficult to recognize this during infancy and childhood. Definite depressive illnesses occurring in adolescence, adulthood, and during the senium have been described and are the subject of this presentation. The primary symptom of depressive illness is the generally depressed affect of the individual. This varies considerably with the type of depressive illness, the personality make-up of the patient, his emotional defense patterns, and the nature of the precipitating factors. Often mild depressive symptoms are not overtly expressed by the individual in that his depressive preoccupations are suppressed from others, and therefore may be difficult to detect. However, indications of the depression are usually manifest in some patterns of behavior such as a general pessimistic attitude, hopelessness about the future, vague somatic complaints, fatigue, loss of sleep, appetite, and weight, difficulty in concentration, and disturbed psychomotor activity, such as either retardation or agitation. These symptoms may develop acutely and persist for a short time or occur in chronic form. The thoughts of the individual dwell on feelings of self-blame, worthlessness, self-abnegation, and frequently suicide. Associated physiologic phenomena are often of considerable significance and include such things as blurring of vision, dryness of the mouth, anorexia, constipation, general fatigue, and sometimes such symptoms as amenorrhea in women or failure of potency in men.
Comments on "Low-energy CSMT carry generators and binary adders"

The author has presented a multiplexer-based carry-select modified tree (CSMT) adder design. It was correctly pointed out in Section VI that these multiplexer-based adders are not just limited to redundant-to-binary-conversion-based adders, but can also be used in the context of carry-save binary adders.
The surface chemistry of stainless steel and evaporated titanium layers in tokamaks

Abstract The combined use of X-ray photoelectron spectroscopy and secondary ion mass spectroscopy is shown to be a powerful tool in the investigation of the chemical modifications of a surface in interaction with a plasma. The reported investigations are performed in-situ in the surface analysis station of the PDX tokamak. The evolution of stainless steel surfaces is followed after various treatments such as hydrogen glow discharge conditioning (GDC), exposure to tokamak discharges, and ion sputtering. Iron oxides are shown to be partially reduced by exposure to GDC: the metal-oxide binding is converted to metal-hydroxide binding from which water can be desorbed. The oxygen behaviour on evaporated titanium films is substantially different: the oxide layer evolves to higher oxidation states during exposure to GDC. In contrast, the behaviour of carbon is identical on both stainless steel and titanium surfaces: carbon is removed during exposure to GDC via the formation of methane which can spontaneously desorb from the surface.
An aspect of translational control of protein synthesis in aging: changes in the isoaccepting forms of tRNA in Turbatrix aceti.

Abstract Transfer RNA from the nematode Turbatrix aceti was examined for age-related changes in isoaccepting forms for sixteen amino acids. This was considered to be an index for possible changes at the translational level of protein synthesis. Aged T. aceti were obtained by the use of hydroxyurea to block reproduction, and their t RNA was purified. This was compared by reverse phase chromatography with t RNA from young T.aceti exposed to hydroxyurea for a short time. Chromatography revealed single peaks for the t RNA of seven amino acids and multiple peaks for t RNA of nine. Of these, only the t RNA for arginine any tyrosine showed consistent age-related differences, which were not attributable to either any decrease in mitochondria in old worms or the presence of eggs in only the control worms. The changes were not due to a general short-term effect of hydroxyurea.
Communication: Time- and space-sliced velocity map electron imaging

We develop a new method to achieve slice electron imaging using a conventional velocity map imaging apparatus with two additional components: a fast frame complementary metal-oxide semiconductor camera and a high-speed digitizer. The setup was previously shown to be capable of 3D detection and coincidence measurements of ions. Here, we show that when this method is applied to electron imaging, a time slice of 32 ps and a spatial slice of less than 1 mm thick can be achieved. Each slice directly extracts 3D velocity distributions of electrons and provides electron velocity distributions that are impossible or difficult to obtain with a standard 2D imaging electron detector.
Do maximum intensity projection images truly capture tumor motion

Purpose For the treatment of patients with lung cancer, internal target volume frequently is determined by using maximum intensity projection (MIP) images generated by means of four-dimensional computed tomography (4D-CT). To check the accuracy of MIPs for various target motions, especially for targets moving irregularly, we performed phantom studies using a programmable dynamic lung phantom. Methods and Materials A custom-built programmable lung phantom was used to simulate irregular target motions along the superior-inferior direction. After scanning in helical mode using 4D-CT, reconstructed phase and MIP images were imported into the Pinnacle 8.0 treatment planning system for image analysis. Results For all regular periodic target motions with constant amplitude and period, the measured MIP target span along the superior-inferior direction was accurate within 2–3 mm of the real target motion span. For irregular target motions with varying amplitudes and periods, the measured MIP target span systematically underrepresented the real range of target motion by more than 1 cm in some cases. The difference between measured MIP target span and real target span decreased as the target moved faster. We associate these discrepancies with the fact that current reconstruction algorithms of commercial 4D-CT are based on phase binning. Conclusions According to our phantom measurements, MIP accurately reflects the range of target motion for regular target motion. However, it generally underestimates the range of target motion when the motion is irregular in amplitude and periodicity. Clinical internal target volume determination using MIP requires caution, especially when there is breathing irregularity.
Influence of Marmota monax on Vegetation in Hayfields

Examination of vegetation around 29 woodchuck ( Marmota monax ) burrows in two hayfields in Connecticut revealed that grass biomass decreased, and forb biomass increased, as a function of distance from burrows. In addition, orchard grass ( Dactylis glomerata ) <2 m from burrows was more lush and exhibited significantly greater levels of crude protein than orchard grass 15 m away. Over an entire field, woodchucks caused an increase in biomass of orchard grass an average of 7.4% and reduced the biomass of alfalfa ( Medicago sativa ) by 2.5%. Differential selection of orchard grass and alfalfa as food, release of grass from competition with alfalfa, and enhanced levels of nitrogen from feces all were plausible factors responsible for the distance-dependent differences in growth of vegetation.
Cross-Strand Coupling of a β-Hairpin Peptide Stabilized with an Aib-Gly Turn Studied Using Isotope-Edited IR Spectroscopy

Isotope-edited IR spectroscopy was used to study a series of singly and doubly 13CO-labeled β-hairpin peptides stabilized by an Aib-Gly turn sequence. The double-labeled peptides have amide I‘ IR spectra that show different degrees of vibrational coupling between the 13C-labeled amides due to variations in the local geometry of the peptide structure. The single-labeled peptides provide controls to determine frequencies characteristic of the diagonal force field (FF) contributions at each position for the uncoupled 13CO modes. Separation of diagonal FF and coupling effects on the spectra are used to explain the cross-strand labeled spectral patterns. DFT calculations based on an idealized model β-hairpin peptide correctly predict the vibrational coupling patterns. Extending these model results by consideration of frayed ends and the hairpin conformational flexibility yields an alternate interpretation of details of the spectra. Temperature-dependent isotopically labeled IR spectra reveal differences in the...
Rapid In Vitro Derivation of Endothelium Directly From Human Cancer Cells

The development of an independent blood supply by a tumor is essential for maintaining growth beyond a certain limited size and for providing a portal for metastatic dissemination. Host-derived endothelial cells (ECs) residing in and compromising the tumor vasculature originate via distinct processes known as sprouting angiogenesis and vasculogenesis. More recently ECs originating directly from the tumor cells themselves have been described although the basis for this phenomenon remains poorly understood. Here we describe in vitro conditions that allow lung and ovarian cancer cells to undergo a rapid and efficient transition into ECs that are indistinguishable from those obtained in vivo. A variety of methods were used to establish that the acquired phenotypes and behaviors of these tumor-derived ECs (TDECs) closely resemble those of authentic ECs. Xenografts arising from co-inoculated in vitro-derived TDECs and tumor cells were also more highly vascularized than control tumors; moreover, their blood vessels were on average larger and frequently contained admixtures of host-derived ECs and TDECs derived from the initial inoculum. These results demonstrate that cancer cells can be manipulated under well-defined in vitro conditions to initiate a tumor cell-to-EC transition that is largely cell-autonomous, highly efficient and closely mimics the in vivo process. These studies provide a suitable means by which to identify and perhaps modify the earliest steps in TDEC generation.
Descriptive audience profiles of diferent daily newspaper sections

(1978). Descriptive audience profiles of diferent daily newspaper sections. Journal of Applied Communication Research: Vol. 6, No. 1, pp. 31-36.
Characterization of acute functional tolerance to the hypnotic effects of ethanol in mice.

Background: Acute functional tolerance (AFT) to ethanol-induced hypnosis is one of the main factors that affect the duration of ethanol-induced loss of righting reflex (LRR: “sleep time”). Investigators who use duration of LRR as a measure of ethanol-induced sedation should consider the potential magnitude and time course of this neuroadaptation when interpreting their results. However, AFT to the hypnotic effects of ethanol has not been well characterized. The present study explored this form of AFT using a novel method of monitoring LRR in mice. Methods: Genetically heterogeneous mice were used to study effects of dose and time on the development of AFT. Mice were treated with different dose regimens and tested for LRR after hypnotic doses using a cylindrical restrainer. Measures of initial sensitivity and AFT to ethanol-induced hypnosis were calculated and analyzed. Inbred strains of mice were then characterized for AFT magnitude after a single ethanol dose. Results: Results showed that (a) AFT developed in a dose-dependent fashion but attained an apparent maximum value; (b) AFT to ethanol-induced hypnosis could develop partially after a small, subhypnotic dose; (c) AFT developed very rapidly and approached its maximum for a given dose by the 10th min after injection of ethanol; and (d) AFT has a strong genetic component. Conclusion: Although specific for AFT to the hypnotic effects of ethanol, the present findings expand general knowledge about acute tolerance and should also be useful for investigators who use loss of righting reflex as a measure of ethanol sensitivity.
A 3-disulfide mutant of mouse prion protein expression, oxidative folding, reductive unfolding, conformational stability, aggregation and isomerization.

Abstract The structure of wild-type mouse prion protein mPrP(23–231) consists of two distinctive segments with approximately equal size, a disordered and flexible N-terminal domain encompassing residues 23–124 and a largely structured C-terminal domain containing about 40% of helical structure and stabilized by one disulfide bond (Cys 178 –Cys 213 ). We have expressed a mPrP mutant with 4 Ala/Ser ⇒ Cys replacements, two each at the N-(Cys 36 , Cys 112 ) and C-(Cys 134 , Cys 169 ) domains. Our specific aims are to study the interaction between N- and C-domains of mPrP during the oxidative folding and to produce stabilized isomers of mPrP for further analysis. Oxidative folding of fully reduced mutant, mPrP(6C), generates one predominant 3-disulfide isomer, designated as N -mPrP(3SS), which comprises the native disulfide (Cys 178 –Cys 213 ) and two non-native disulfide bonds (Cys 36 –Cys 134 and Cys 112 –Cys 169 ) that covalently connect the N- and C-domains. In comparison to wild-type mPrP(23–231), N -mPrP(3SS) exhibits an indistinguishable CD spectra, a similar conformational stability in the absence of thiol and a reduced ability to aggregate. In the presence of thiol catalyst and denaturant, N -mPrP(3SS) unfolds and generates diverse isomers that are amenable to further isolation, structural and functional analysis.
Scalable enantioselective total synthesis of taxanes

Taxanes form a large family of terpenes comprising over 350 members, the most famous of which is Taxol (paclitaxel), a billion-dollar anticancer drug. Here, we describe the first practical and scalable synthetic entry to these natural products via a concise preparation of (+)-taxa-4(5),11(12)-dien-2-one, which has a suitable functional handle with which to access more oxidized members of its family. This route enables a gram-scale preparation of the 'parent' taxane--taxadiene--which is the largest quantity of this naturally occurring terpene ever isolated or prepared in pure form. The characteristic 6-8-6 tricyclic system of the taxane family, containing a bridgehead alkene, is forged via a vicinal difunctionalization/Diels-Alder strategy. Asymmetry is introduced by means of an enantioselective conjugate addition that forms an all-carbon quaternary centre, from which all other stereocentres are fixed through substrate control. This study lays a critical foundation for a planned access to minimally oxidized taxane analogues and a scalable laboratory preparation of Taxol itself.
Multivariate predictors of intravascular ultrasound end points after directional coronary atherectomy

Objectives. This study attempted to identify the clinical, angiographic, procedural and intravascular ultrasound predictors of directional atherectomy results assessed by intravascular ultrasound. Background. Several angiographic and intravascular ultrasound variables have been associated with the outcome of directional coronary atherectomy. No study has incorporated both modalities into a predictive model. Methods. One hundred seventy patients were analyzed using preintervention and postintervention intravascular ultrasound and quantitative angiography. Clinical and procedural variables were collected by independent chart review. Quantitative and qualitative angiographic analysis was performed by a core laboratory in blinded manner. Intravascular ultrasound was performed using a transducer-tipped catheter, rotating within a stationary imaging sheath, and withdrawn automatically at 0.5 mm/s. Clinical, procedural, angiographic and ultrasound variables were tested iin a multivariate linear regression model. Dependent ultrasound variables included postatherectomy lumen cross-sectional area and percent cross-sectional narrowing (plaque plus media/external elastic membrane cross-sectional area) and, in a subgroup of 47 patients studied using volumetric analysis, percent plaque volume removal. Results. By multivariate stepwise linear regression analysis, predictors of residual lumen cross-sectional area (correcting for reference lumen area) included arc of calcium and preatherectomy plaque plus media cross-sectional area; predictors of residual cross-sectional narrowing were arc of calcium, preatherectomy plaque plus media cross-sectional area and lesion length; and predictors of percent plaque volume removal were arc of calcium and atherectomy device size. Conclusions. The preintervention lesion arc of calcium measured by intravascular ultrasound is the most consistent predictor of the effectiveness and results of directional coronary atherectomy.
Electron-nuclear double-resonance experiments in hydrogenated amorphous silicon.

Electron-nuclear double-resonance (ENDOR) measurements are performed in undoped, doped, and compensated a-Si:H. Matrix ENDOR and distant ENDOR are identified as the effective ENDOR mechanisms by an investigation of the transient ENDOR response, and conditions for the experimental parameters to optimize the response are given. ENDOR spectra due to $^{1}\mathrm{H}$ and $^{31}\mathrm{P}$ nuclei are found to be subject to a microwave coherence splitting, which allows a calibration of the microwave field in the ESR cavity. Several well-resolved lines of unknown origin are observed in compensated a-Si:H by light-induced ENDOR. It is shown that transient ENDOR experiments can be used to measure electronic and nuclear spin-lattice relaxation times at low temperatures and an application of this capability to study reversible light-induced changes in a-Si:H is presented. The discussion of the experimental results addresses the question of what kind of information about the structure of a-Si:H can be obtained by ENDOR experiments.