cssi/SciSciGPT-SciSciNet huggingface dataset:
The Trading Nation’s Dilemma: The Functions of the Law of International Trade

The public law of international trade acts to restrain national governments from interfering in private trade transactions. It is based upon treaties and other international agreements made, administered and enforced by the national governments to which it applies. Why do governments agree to limit their freedom of action by rules of law? This article presents a fresh explanation of the underlying functions of the international trade law regime, using a simple game theory framework to organize the analysis. This article argues that the law of international trade functions to help the governments of trading nations reach a satisfactory resolution of a complex dilemma. In the context of domestic decision-making, public officials deciding whether to grant protection to import-competing industries are faced with an unpleasant trade-off. There are short-run political gains for granting protection, with corresponding losses for refusing. However, granting protection may conflict with principles or values connected with the national interest or the interests of consumers. On the international level, trading nation governments find themselves in a situation akin to the two-player game theory scenario known as the Prisoners' Dilemma. When each player in the game follows his dominant strategy, the result is an "equilibrium" outcome in which each is worse off than if each had followed the alternative strategy. The law of international trade functions to inhibit national governments from following what appear to be rational short-run courses of action in the interest of achieving superior long-run outcomes for their nations and perhaps for themselves.
How Far Can You Trust A Computer

The history of attempts to secure computer systems against threats to confidentiality, integrity, and availability of data is briefly surveyed, and the danger of repeating a portion of that history is noted. Areas needing research attention are highlighted, and a new approach to developing certified systems is described.
Fatty acid oxidation by spores of Penicillium roqueforti.

When 1 μm sodium octanoate was the substrate for spores, most of the molecule was recovered as CO2 and no ketone was produced. However, when larger concentrations (20 μm) were used as substrate, part of the molecule was converted to methyl ketone and part was completely oxidized. Optimal conditions for the production of 2-heptanone were determined because of the importance of this compound in giving aroma and flavor to mold-ripened cheeses. Optimal ketone formation was not dependent upon the temperature and length of time at which the spores were stored. The spore suspensions were stored for over 36 months at 4 C without losing their ability to convert octanoic acid to 2-heptanone. The oxidation of octanoic acid was inhibited by cyanide, carbon monoxide, mercury, 2,3-dimercapto-1-propanol, and α, α-dipyridyl. No ketone was produced under anaerobic conditions. Although no intermediates of fatty acid oxidation were isolated, since an active cell-free preparation could not be obtained, this investigation has yielded some evidence for the beta oxidation of the fatty acids by spores of Penicillium roqueforti.
Realization and implementation of adaptive state-space recursive filters

The authors extend the LMS (least mean squares) adaptation algorithm to state-space recursive filtering. Based on the state equations in the time domain, gradients for all parameters are formulated by matrix derivative linear operations and are calculated recursively. The stability of the filter during the adaptive process is guaranteed by adding the constraints of a specified system matrix A. Simulation results show that any desired state-space system can be achieved by initializing the system properly. Since the adaptive state-space filtering requires intensive computations and all computations involved are matrix operations, a high-speed VLSI architecture is presented for real-time or near real-time applications. >
Macau’s Pataca and identity

Purpose – For over a 100 years, Macau’s Pataca has been tied to Macau’s identity, its independent financial existence and its links to the Lusophone world. Its role as a supporter of the Macau identity relies upon the strength and capabilities of its financial institutions, the Macau Monetary Authority and banking institutions that issue its currency (Banco Nacional Ultramarino and Bank of China). The paper aims to discuss the above issue. Design/methodology/approach – The author uses statistics and data from the Macau Monetary Authority. Findings – There are three possible scenarios that could emerge: first, retired in favor of the RMB, the HK dollar; second, maintained with its use expanding as Macau’s revenues and investment funds grow, or third, become a force for stronger economic cohesion and identity among the Lusophone nations. Practical implications – Which of these scenarios will offer Macau the highest possibility of maintaining its international network of relationships and representation, div...
Ion bombardment of Ni(110) studied with inverse photoemission spectroscopy and low-energy electron diffraction

Abstract Inverse photoemission spectroscopy (IPES) performed on clean Ni(110) reveals an unoccupied electronic surface state with energy ~ 2.5 eV above the Fermi level for emission near the Ȳ point of the Surface Brillouin Zone. Ion bombardment of the sample creates defects that reduce the intensity of the peak in IPES spectra. Sharp, intense diffraction spots in low-energy electron diffraction (LEED) patterns taken of the clean surface become dimmer after bombardment. Results of these measurements are compared to Monte Carlo simulations of the sputtering process to ascertain the approximate size of clean patches on the sample necessary to sustain the IPES and LEED features. At 170 K, the IPES surface state peak appears closely associated with the population of surface atomic sites contained in clean circular patches of about 50 atoms. The LEED patterns persist to greater degrees of sputtering and are associated with smaller clean patches. Both measurements performed at 300 K indicate significant self-annealing of the sputtering damage.
Anaerobic oxidation of crude oil hydrocarbons by the resident microorganisms of a contaminated anoxic aquifer.

The biodegradation of two crude oils by microorganisms from an anoxic aquifer previously contaminated by natural gas condensate was examined under methanogenic and sulfate-reducing conditions. Artificially weathered Alaska North Slope crude oil greatly stimulated both methanogenesis and sulfate reduction. Gas chromatographic analysis revealed the entire n-alkane fraction of this oil (C13−C34) was consumed under both conditions. Naphthalene, 2-methylnaphthalene, and 2-ethylnaphthalene were also biodegraded but only in the presence of sulfate. Alba crude oil, which is naturally depleted in n-alkanes, resulted in a relatively modest stimulation of methanogenesis and sulfate reduction. Polycyclic aromatic hydrocarbon biodegradation was similar to that found for the Alaska North Slope crude oil, but a broader range of compounds was metabolized, including 2,6-dimethylnaphthalene and 2,7-dimethylnaphthalene in the presence of sulfate. These results indicate that n-alkanes are relatively labile, and their biodegr...
Spatial Distribution of Soil Carbon and Nitrogen Pools under Grazed Tall Fescue

Cattle (Bos taurus) behavior may be an important variable controlling the spatial distribution of soil C and N pools in long-term, grazed pastures. Shade and water sources are more frequented areas of a pasture that can also serve as camping areas where excreta are deposited. We sampled a Cecil sandy loam (fine, kaolinitic, thermie Typic Kanhapludult) under tall fescue (Festuca arundinacea Schreb.) at distances of 1, 10, 30, 50, and 80 m from permanent shade or water sources at the end of 8 and 15 yr of grazing. To a depth of 75 mm. soil bulk density was 1.15 Mg m -3 at 1 m and averaged 1.00 Mg m -3 at other distances from shade or water. To a depth of 300 mm, soil organic C was 4.6 kg m -2 at 1 m, 4.3 kg m -2 at 10 m, and = 4.0 kg m 2 at distances of 30, 50, and 80 m from shade or water. Particulate organic C averaged 1.53 kg m 2 at distances of I, 10, and 30 m and 1.30 kg m -2 at distances of 50 and 80 m from shade or water. Soil microbial biomass C, basal soil respiration, and net potential N mineralization were also greater nearer shade or water than farther away. Although lateral distribution effects were most dramatic at a depth of 0 to 25 mm, similar effects were observed even at a depth of 150 to 300 mm. Long-term cattle grazing in relatively small paddocks (0.7-0.8 ha) with permanent shade and water sources resulted in significant lateral and vertical changes in soil organic C and N pools.
Grace and Recompense: Reflections on a Pauline Paradox

At several points-notably Rom 2:6,13-Paul expresses a notion of recompense that stands in tension with his proclamation of justification by grace through faith. A partial resolution of the problem is made possible by a recognition that genuine faith expresses itself in deeds. But the tension remains: what this solution shows is an internal strain on the meaning of justification by faith. A Whiteheadian understanding of language fosters an appreciation of the ability of the text to signify through such tension. But it also reveals a tendency in Paul's thought toward a coherent conceptualization that does justice to both elements in the paradox. A "reconstruction" of Paul's message is offered as a way of honoring this tendency and allowing his most basic claims to function freely.
Impaired predictive motor timing in patients with cerebellar disorders.

The ability to precisely time events is essential for both perception and action. There is evidence that the cerebellum is important for the neural representation of time in a variety of behaviors including time perception, the tapping of specific time intervals, and eye-blink conditioning. It has been difficult to assess the contribution of the cerebellum to timing during more dynamic motor behavior because the component movements themselves may be abnormal or any motor deficit may be due to an inability to combine the component movements into a complete action rather than timing per se. Here we investigated the performance of subjects with cerebellar disease in predictive motor timing using a task that involved mediated interception of a moving target, and we tested the effect of movement type (acceleration, deceleration, constant), speed (slow, medium, fast), and angle (0°, 15° and 30°) on performance. The subjects with cerebellar damage were significantly worse at interception than healthy controls even when we controlled for basic motor impairments such as response time. Our data suggest that subjects with damage to the cerebellum have a fundamental problem with predictive motor timing and indicate that the cerebellum plays an essential role in integrating incoming visual information with motor output when making predictions about upcoming actions. The findings demonstrate that the cerebellum may have properties that would facilitate the processing or storage of internal models of motor behavior.
Influences of target and nontarget shapes on target identification

The orientation of a nontarget in a location-cuing paradigm has been shown to affect accuracy of identification of target orientation when modified plus-signs (Ts) are the stimuli. In the current study, similar effects were found with Landolt C (C) stimuli. Both shapes of targets were identified by orientation. Moreover, targets were affected by nontargets whether both target and nontarget were the same shape or if they were different shapes. A single nontarget with an orientation that matched that of the target improved accuracy of identification of target orientation, whereas a nontarget with an orientation that did not match that of the target impaired accuracy of identification of target orientation, even though the nontargets appeared in locations that were never cued and could never contain targets. The data are consistent with either the Variable and Permeable Filters metaphor or a response competition account.
A simultaneous assay system for n-acetylgalactosamine and N-acetylgalactosaminitol using gas chromatography/mass spectrometry.

Abstract A procedure is described, using gas chromatography/mass spectrometry to identify and quantitate various sugar alditol acetates, which will simultaneously quantitate N-acetylgalactosamine and N-acetylgalactosaminitol. N-acetylgalactosamine is distinguished from N-acetylgalactosaminitol by reduction with sodium borodeuteride and determining relative intensities of the ion pairs m e 84, 85; 102, 103; and 144, 145. The method is adequate for determining amounts of these sugars in the range of 40–1000 nmol.
Carotid Blowout with Infection: Management with Endovascular and Open Vascular Approaches A Case Report

The management of patients with head and neck cancer can be complicated by massive carotid artery hemorrhage, often requiring ligation owing to the emergent conditions and scarring from previous surgery and radiation. A case of emergent endovascular management of carotid artery hemorrhage in a patient treated for pharyngeal carcinoma is described. Hemorrhage was controlled, but on follow-up the patient developed a carotid-cutaneous fistula with exposure of the coils. Further management required the use of autogenous vein to replace the involved vessels. This case demonstrates that endovascular control of carotid hemorrhage can be successful, but close follow-up is necessary to identify potential subsequent complications.
Old versus new: weighing the evidence between the first- and second-generation antipsychotics

In our opinion the best guide to prescribing antipsychotics is the clinician’s experience with his patients and in particular the patient being treated. If treatment works, stick with it. We feel it is also important for the clinician to consider the evidence from well-controlled double-blind random-assignment studies because in “evidence-based medicine,” biases both known and unknown are controlled by blinding and randomization. The purpose of this paper is to summarize and discuss the evidence on efficacy. Choice of antipsychotic, in our opinion, is probably the most important decision that the clinician makes for the psychotic patient. This involves the choice of drug, its dose, balancing efficacy, side-effects and cost.
COMPARATIVE EFFECTS OF PHOSPHOLIPASE A2 NEUROTOXINS AND ENZYMES ON MEMBRANE POTENTIAL AND NA+/K+ ATPASE ACTIVITY OF RAT BRAIN SYNAPTOSOMES

Beta-Bungarotoxin (beta-BuTX) and notexin are phospholipase A2 (PLA2) neurotoxins which cause an irreversible blockade of neurotransmitter release through specific and potent effects at the presynaptic nerve terminal; however, their mechanism of action is uncertain. We examined the effects of beta-BuTX and notexin on Na+/K+ ATPase activity using Sprague-Dawley rat brain synaptosomes in order to determine if alterations in activity might modulate neurotoxin-induced depolarization. Treatment of synaptosomes with 0.05 to 5 nM beta-BuTX, notexin, and Naja naja atra and Naja nigricollis PLA2 (PLA2 enzymes without selective presynaptic actions) caused a dose-dependent depolarization of synaptosomes with no differences being observed between the effects of the PLA2 neurotoxins and enzymes. N. nigricollis PLA2 (0.5 nM; 20 min) slightly stimulated Na+/K+ ATPase activity while beta-BuTX and notexin (0.5 nM: 10 and 20 min) were without effect. With 50 nM concentrations beta-BuTX and notexin stimulated Na+/K+ ATPase activity, while N. nigricollis and N. n. atra PLA2 inhibited activity. The effects on membrane potential and Na+/K+ ATPase were antagonized or blocked by EDTA (10 mM) and bovine serum albumin (1 mg/ml), suggesting that PLA2 enzymatic activity is essential for their effects on membrane potential and Na+/K+ ATPase activity. Following neurotoxin and enzyme pretreatment, we found a biphasic correlation between synaptosomal free fatty acid (FFA) levels and Na+/K+ ATPase activity, where Na+/K+ ATPase is stimulated by low levels of FFA (0.13 to 0.22 mumol/mg protein) and antagonized by FFA levels in excess of 0.34 mumol/mg protein. In contrast there was a linear correlation between the extent of FFA production and membrane depolarization. We propose that the presynaptic depolarizing actions of beta-BuTX and notexin are not mediated through modulation of Na+/K+ ATPase activity and that the changes observed in ATPase activity and possibly membrane potential are directly due to PLA2 enzymatic activity and the production of FFA.
Topological Spines: A Structure-preserving Visual Representation of Scalar Fields

We present topological spines-a new visual representation that preserves the topological and geometric structure of a scalar field. This representation encodes the spatial relationships of the extrema of a scalar field together with the local volume and nesting structure of the surrounding contours. Unlike other topological representations, such as contour trees, our approach preserves the local geometric structure of the scalar field, including structural cycles that are useful for exposing symmetries in the data. To obtain this representation, we describe a novel mechanism based on the extraction of extremum graphs-sparse subsets of the Morse-Smale complex that retain the important structural information without the clutter and occlusion problems that arise from visualizing the entire complex directly. Extremum graphs form a natural multiresolution structure that allows the user to suppress noise and enhance topological features via the specification of a persistence range. Applications of our approach include the visualization of 3D scalar fields without occlusion artifacts, and the exploratory analysis of high-dimensional functions.
From proficiency to expert, when does the learning curve for robotic-assisted prostatectomies plateau? The Columbia University experience

To describe our single-institution experience with our first 70 consecutive robotic-assisted laparoscopic prostatectomies (RLPs) with particular focus on effect of learning curve on operative time, length of stay and blood loss. We also report our short-term outcome data in this heterogeneous cohort of men with prostate cancer (PCa). We reviewed our institutional database for the first 70 consecutive RLPs performed by a single surgeon (DS) over a 21-month period (March 2003 to December 2004). Surgical, pathologic and postoperative outcomes were analyzed. In order to evaluate the impact of the surgeon's and institution's learning curve on outcomes, the cases were divided into quartiles and stratified accordingly to identify trends. Ninety-nine percent (69/70) of all procedures were successfully completed robotically. Mean blood loss, operative time and mean length of stay were 231 ml, 264 min and 1.9 days, respectively. At follow-up, 76% of all patients were fully continent (no pads) and 93% (62/67) had undetectable PSA. The most dramatic improvement in surgical outcomes was seen within the first quartile of cases; however a statistically significant improvement trend existed throughout the series. This included a downward trend in operative time (P < 0.00001), estimated blood loss (P < 0.00001), and length of hospital stay (P = 0.003). This trend continued when controlled for in a multivariate analysis. Our results compare favorably with other RLP series as well as conventional laparoscopic series. Proficiency is achieved within the first 20 cases; however surgical outcomes continue to improve for RLP throughout the first 70 cases and perhaps beyond.
Initial uterine alterations caused by developmental exposure to tamoxifen

Abstract Neonatal treatment of rodents with the widely used antiestrogen tamoxifen causes endometrial cancer and reproductive tract lesions reminiscent of the diethylstilbestrol (DES) syndrome. To evaluate the initial alterations induced in the developing uterus by tamoxifen or DES, neonatal Sprague-Dawley rat pups received 100 μg of tamoxifen (Group 1), 1 μg of DES (Group 2), or vehicle (Group 3) subcutaneously on days 1 through 5, and their uteri were studied by light microscopy, 5-bromo-2′ deoxyuridine immunohistochemistry, and computer-based morphometry. At Postnatal Day 6, epithelial hypertrophy (184.3% and 237.9% of controls) and myometrial thickening (151.9% and 180.0%) accounted for the uterotrophic effects of tamoxifen and DES. Evidence of secretory activity in epithelial cells, reduction of the epithelial BrdU-labeling index to 18.1% (tamoxifen) and 41.1% (DES) of controls, premature endometrial and myometrial differentiation, and the presence of eosinophils in both treatment groups suggested that tamoxifen exerted a DES-like estrogenic action on the developing uterus. These findings indicate that immediate epithelial and stromal-myometrial uterine alterations are found at Postnatal Day 6 after neonatal tamoxifen treatment.
Vision Science for Visual Technology

As our primary means of gathering information from the world about us, vision has always occupied a central place in human factors. Beginning in the early 1980's, the Vision Group at NASA Ames Research Center sought to move visual human factors from its primarily empirical foundations to a new, model based formulation. The intent was to do this through development of computational models of visual performance. These would be more general than ad hoc empirical measurements, would be amenable to refinement over time, and would serve as the basis for computational human factors engineering tools. Since then the Vision Group has made some important contributions to fundamental vision science, and has also begun to fulfill the program envisioned at its outset.
Constraint matching as a means of designing biochemical experiments in multi-enzyme systems

A method of qualitative analysis by constraint matching, where expectations derived from theory or from data bases are systematically compared against experimental findings, is described. This was originally developed as an artificial intelligence technique to analyze enzyme kinetic mechanism determinations. It is shown to have been used (without computer involvement) in designing experiments involving a few enzymes, and is suggested as a useful experimental design tool. The experiments in question validate the behavior of insulinoma extracts as models for pancreatic islet glycolysis, which conform to the expectations from the relevant enzyme literature. Possible generalization to other areas of biological research is suggested.
Baclofen does not alter the reinforcing, subject-rated or cardiovascular effects of intranasal cocaine in humans.

Rationale There is evidence from research in animals and humans that the γ-aminobutyric acid B receptor subtype (GABAB) agonist baclofen may have promise as a pharmacotherapy for cocaine addiction.
Rawls and the status of political liberty

: In his late work, Rawls makes strong claims about the status of political liberty. These claims, if accepted, would have significant implications for the content of “justice as fairness.” I discuss the nature of these claims, clarifying Rawls's fair value guarantee of the political liberties and critically discussing the arguments that he and others have given for assigning special importance to the political liberties. I conclude that justice as fairness, properly understood, is not a deeply democratic conception of justice.
Mapping class I gene sequences in the major histocompatibility complex

The class I glycoproteins of the major histocompatibility complex (MHC) are products of closely linked genes on the 17th chromosome of the mouse. Four highly homologous cell surface proteins, K, D, L, and Qa-2 (refs 1–4), belonging to this multigene family have been analysed. Several additional members5–7, M, R, TL, are indicated by biochemical data and recent serological data suggest the family is larger8. Recent reports using recombinant DNA technology suggest that the class I system is an extensive multigene family9–12. In this report we describe results of experiments using restriction enzyme digestion of DNA from a group of standard, congeneic and MHC recombinant mouse strains followed by hybridization to H–2 cDNA probes. Particular bands of hybridization can be assigned to specific H–2 haplotypes and, therefore, to the MHC region of the 17th chromosome. A number of the MHC polymorphic bands have been assigned to genetic map positions in the K and D-L regions of the H–2 complex. Additional class I gene sequences map outside the boundaries of the traditional H–2 complex (K, I, S, D), into the Qa-T1a region. At least one sequence is centromeric to the K locus. Further, amino terminal and carboxy terminal probes show different restriction patterns, suggesting that the exons corresponding to the different domains of the class I glycoproteins may have different evolutionary histories.
Political resource allocation, controlled agendas, and the status quo

Economic analysis requires modelling political as well as market resource allocation. Voting institutions, in particular two-candidate majority rule elections and voting on motions, have been a primary focus of recent analytical developments. In the case of a single good to be allocated politically, standard assumptions lead to 'single-peakedness' of voter preferences over the set of alternatives. When, in choosing between a pair of available alternatives, every voter votes for his preferred alternative, the allocative equilibrium is the 'Condorcet point' or political allocation most desired by the median voter (Bowen, 1943; Black, 1958; Riker and Ordeshook, 1973). This result concerning the dominance of the median voter's ideal allocation depends importantly on the nature of competition in the allocation process. In the context of the political allocation of economic goods, the 'median voter' outcome is typically justified on the basis of an underlying but usually unmodeled process of political competition between two candidates for elective office, wherein the dominant strategy for each candidate is to offer to provide the level of public spending that corresponds to the median voter's ideal expenditure. Such a view of equilibrium under majority rule (when equilibrium exists) may be very unrepresentative of political processes. Many such processes, particularly those related to collective expenditure determination, may be more appropriately characterized as ones in which some group has the power to make a proposal to the voters, and thereby set the agenda. This group, which we call the agenda setter, by having monopoly power over the proposal placed before the electorate, can confront the voters with a 'take it or leave it' choice. Because 'competitive' substitutes to the setter's proposal are not offered, the median voter cannot simply 'hold out' until the Condorcet point is proposed. When the setter has monopoly power, voters are forced to choose between
Chaos and Intermittency in the Solar Cycle

Where a magnetic flux tube of sufficient strength and cross section protrudes from the sun, convection is locally inhibited and a sunspot appears. The number of spots on the sun at any time varies in a cyclic, but aperiodic, manner. Models with chaos and intermittency can capture the main qualitative aspects of this temporal variability, especially if they display the mechanism of on-off intermittency. Capturing the spatio-temporal aspects of the sunspot cycle requires a more complicated model but a description in terms of waves of excitation seems promising. To clarify these possibilities, qualitative introductory remarks about chaos theory itself are included in this narrative.
Structural Understanding of the Glutathione-dependent Reduction Mechanism of Glutathionyl-Hydroquinone Reductases

Glutathionyl-hydroquinone reductases (GS- HQRs) are a newly identified group of glutathione transferases, and they are widely distributed in bacteria, halobacteria, fungi, and plants. GS-HQRs catalyze glutathione (GSH)-dependent reduction of glutathionyl-hydroquinones (GS-hydroquinones) to hydroquinones. GS-hydroquinones can be spontaneously formed from benzoquinones reacting with reduced GSH via Michael addition, and GS-HQRs convert the conjugates to hydroquinones. In this report we have determined the structures of two bacterial GS-HQRs, PcpF of Sphingobium chlorophenolicum and YqjG of Escherichia coli. The two structures and the previously reported structure of a fungal GS-HQR shared many features and displayed complete conservation for all the critical residues. Furthermore, we obtained the binary complex structures with GS-menadione, which in its reduced form, GS-menadiol, is a substrate. The structure revealed a large H-site that could accommodate various substituted hydroquinones and a hydrogen network of three Tyr residues that could provide the proton for reductive deglutathionylation. Mutation of the Tyr residues and the position of two GSH molecules confirmed the proposed mechanism of GS-HQRs. The conservation of GS-HQRs across bacteria, halobacteria, fungi, and plants potentiates the physiological role of these enzymes in quinone metabolism.
Transcription factors on the move

We think of transcription factors as being confined to the cell where they are transcribed, but recent work shows they are able to move from cell to cell in plants. Plant cells are thought to communicate through membrane-lined channels called plasmodesmata. Although the size exclusion limit for these pores is small, microinjection experiments indicate that macromolecular trafficking through plasmodesmata occurs and can be regulated. But can functional plant proteins in their normal expression domain also move between cells? A recent paper by Sessions et al. elegantly addresses this question using meristem chimeras. Intriguingly, only one of the two proteins studied moved, thereby setting the stage for analysis of the mechanism and selectivity of protein trafficking between cells.
Microstructural issues in a friction-stir-welded aluminum alloy

Recent observations of microstructures associated with friction-stir welding (FSW) in a number of aluminum alloys have consistently demonstrated the actual weld zone to consist of a (dynamically) recrystallized grain structure resulting from the extreme, solid-state, plastic deformation characterizing the process. Because of solubilities associated with the various precipitates in 7075 and 6061 aluminum alloys, and the fact that the precipitates were either homogeneously distributed throughout both the original (unwelded) work-piece plates and the well zones (or formed varying densities of Widmanstaetten patterns within the original and recrystallized grains), it has been difficult to follow the stirring of stable, second-phase particles from the base metal (work-piece) into the weld zone. In the present investigation, a compositionally modified 1100 aluminum alloy (nominally 99.2% Al, 0.5% Fe, 0.15% Cu, 0.12% Si, 0.05 Mn, 0.04 Ti, balance in weight percent of Be and Mg), forming a stable microdendritic (second-phase), equiaxed, cell structure was friction-stir welded. These thermally stable, geometrically specific, precipitates in the base metal were compared with their disposition within the friction-stir-weld zone. In addition, as-cast plates of this alloy were cold-rolled 50% and friction-stir-welded in order to compare these two schedules (as-cast and 50% cold-rolled) in terms of residual hardness variations andmore » related microstructural issues as well as the effect of prior deformation on the friction-stir welding process.« less
Neuroethology in the service of neurophonetics

Abstract Single-neuron recording methods, as commonly used in neuroethology studies, provide the needed spatial and temporal resolution capacities to generate explicit hypotheses addressing the ‘how’ of language processing. The goal of this article is to describe two well documented neural processing mechanisms that can provide insights into (1) the auditory decoding of speech sounds, and (2) disambiguation of context-induced variability in stop place perception. The neural unit underlying speech sound processing is the combination-sensitive neuron, and the neural entity best suited to resolve context-induced variability in the speech signal is the neural column. The ‘absorption’ of stimulus variability via signal-specific columnar encoding is contrasted to exemplar-based treatments of stimulus variability in neural systems.
Genetic manipulation of AML1-ETO–induced expansion of hematopoietic precursors in a Drosophila model

Among mutations in human Runx1/AML1 transcription factors, the t(8;21)(q22;q22) genomic translocation that creates an AML1-ETO fusion protein is implicated in etiology of the acute myeloid leukemia. To identify genes and components associated with this oncogene we used Drosophila as a genetic model. Expression of AML1-ETO caused an expansion of hematopoietic precursors in Drosophila, which expressed high levels of reactive oxygen species (ROS). Mutations in functional domains of the fusion protein suppress the proliferative phenotype. In a genetic screen, we found that inactivation of EcRB1 or activation of Foxo and superoxide dismutase-2 (SOD2) suppress the AML1-ETO–induced phenotype by reducing ROS expression in the precursor cells. Our studies indicate that ROS is a signaling factor promoting maintenance of normal as well as the aberrant myeloid precursors and suggests the importance of antioxidant enzymes and their regulators as targets for further study in the context of leukemia.
Copolymerization of epoxides and carbon dioxide. Evidence supporting the lack of dual catalysis at a single metal site.

The chromium tetramethyltetraazaannulene catalyst system, Cr(tmtaa)Cl in the presence of a quaternary organic salt, has been employed to further investigate the mechanism of polycarbonate formation between cyclohexene oxide and carbon dioxide. Although the features of the proposed mechanism are generally well-accepted, the question of whether polymer chain propagation occurs from one side of the catalyst in a mono catalytic single-site fashion or from both sides of the N4-ligand plane in a dual catalytic manner. To probe this behavior, the ligand architecture was altered by the addition of a sterically encumbering strap (Cr(stmtaa)Cl), which effectively blocks one side of the complex and limits polymer chain growth to a single side of the catalyst. For direct comparison, an electronically similar catalyst, Cr(smtmtaa)Cl, was prepared to mimic the strap complex while not possessing the site-blocking steric restraints of the full strap. Infrared spectroscopy demonstrated an uptake of 2 equiv of PPNN3 cocata...
Standing on the shoulders of giants: A scientific journey from Singapore to stem cells

Cellular therapy was introduced in the early 1980s as adoptive immunotherapy for cancer and has now expanded to stem cell treatment for a wide variety of indications. During the same period, the concept of the fetus as a patient evolved from fantasy to everyday reality. The intersection of these two fields offers great potential for cures in childhood diseases. The fetal treatment of spina bifida is one such disease. Global surgery has also emerged as a cost effective approach to reducing the worldwide burden of childhood disease.
Squalestatin 1-inducible expression of rat CYP2B: evidence that an endogenous isoprenoid is an activator of the constitutive androstane receptor.

Because our previous studies indicated that squalestatin 1 treatment induces CYP2B expression in primary cultures of rat hepatocytes as a direct consequence of squalene synthase inhibition, we investigated possible underlying mechanisms. Cotransfection of cultured Sprague-Dawley male rat hepatocytes with each of the three sterol regulatory element binding protein (SREBP) transcription factors failed to induce luciferase expression from a squalestatin 1-responsive CYP2B1 reporter plasmid. Squalestatin 1 treatment of primary hepatocyte cultures from male Wistar-Kyoto rats produced a greater induction of CYP2B mRNA than occurred in cultures from female rats, consistent with the previously demonstrated response dimorphism that has been attributed to differences in constitutive androstane receptor (CAR) levels. Cotransfection of female Wistar-Kyoto rat hepatocyte cultures with plasmid expressing either mouse or rat CAR restored squalestatin 1-inducible CYP2B1-reporter expression. Cotransfection of Sprague-Dawley rat hepatocyte cultures with plasmid expressing rat CAR lacking the C-terminal AF-2 subdomain inhibited squalestatin 1-inducible CYP2B1-reporter expression. Squalestatin 1-mediated CYP2B mRNA induction in rat hepatocyte cultures was completely abolished by pretreatment with the 3-hydroxymethyl-3-glutaryl CoA reductase inhibitor pravastatin and was rescued by mevalonate supplementation, whereas phenobarbital-mediated induction was unaffected by these treatments. Finally, direct addition oftrans,trans-farnesol to the culture medium caused the rapid induction of CYP2B mRNA. These results indicate that squalestatin 1 treatment induces CYP2B expression, not by inhibiting sterol synthesis and activating SREBPs, but by evoking the accumulation of an endogenous isoprenoid and activating CAR.
Age and differentiation-related differences in neuron-specific tubulin immunostaining of olfactory sensory neurons.

Abstract Olfactory sensory neurons (OSNs) are unusual mammalian neurons because they are produced continually throughout adult life and because their production is upregulated after injury. Because OSNs also have an unusual immunological profile and do not bind the commonly used antibody markers for neurons, we sought new antibody markers for studies of OSN regeneration. In this report, we characterize the staining patterns of antibodies to the Class III β, neuron-specific, tubulin (NST) in rat olfactory tissue sections, to determine if these antibodies specifically label OSNs. In tissue sections from newborn rats, monoclonal antibodies to NST labeled cell bodies and processes of both immature (olfactory marker protein, OMP, -negative) and mature (OMP-positive) OSNs. In tissue sections from adult rats, immature OSNs showed both cell body and dendrite staining with anti-NST, while mature OSNs showed little or no cell body staining. Mature OSNs appeared to have both axonal and dendritic anti-NST staining. Axonal staining was suggested by the complete labeling of the olfactory nerve bundles and the nerve fiber layer of the olfactory bulb. The extent of labeling was judged by comparison with anti-OMP staining. Mature OSN dendritic staining was suggested because a much higher number of dendrites were anti-NST stained in the epithelium than cell bodies. These changes suggest both age and differentiation-related changes in subcellular distribution of NST in OSNs. NST antibodies are thus good markers for all OSNs in the newborn rat, but selective markers for immature OSNs and mature OSN processes in the adult rat. NST antibodies may also be useful probes for βIII tubulin function in neurons.
A post-transcriptional process contributes to efficient γ-globin gene silencing in definitive erythroid cells

OBJECTIVES The expression of human gamma globin is developmentally regulated through mechanisms that affect the transcriptional activity of its encoding gene. The current manuscript investigates whether the efficiency of this process might be enhanced though an unrecognized post-transcriptional event that defines the stability of gamma-globin mRNA. METHODS Experiments were conducted in vivo in transgenic mice expressing human gamma globin in their adult erythroid cells. The expression of gamma-globin protein was manipulated by breeding the transgene into animals producing different levels of endogenous mouse beta-globin. Changes in the expression of gamma globin were then correlated to measures of gamma-globin mRNA stability in vivo. RESULTS Human gamma globin was expressed at higher levels in thalassemic than in than non-thalassemic control transgenics, paralleling a highly significant increase in the stability of gamma-globin mRNA. Other molecular events-including possible transcriptional induction of the transgene, or an increase in the stability of the gamma-globin protein-did not appear to contribute to the observed increase in transgene expression. As anticipated, the stability of gamma-globin mRNA also fell in bitransgenic animals that co-expressed human beta-globin mRNA. CONCLUSIONS Our results are consistent with a model for dynamic post-transcriptional control of gamma-globin gene expression, through modulation of the stability of its encoding mRNA. Moreover, the stability of gamma-globin mRNA appears to be inversely related to ambient levels of co-expressed beta-globin mRNA. This data suggests that therapeutic gene-reactivation and/or gene-replacement therapies may be particularly effective in individuals with severe forms of beta-thalassemia.
Metal-insulator transition in polyaniline doped with surfactant counter-ion

Polyaniline (PANI) films of superior homogeneity can be prepared by using functionalized protonic acids to protonate the polymer and simultaneously induce solubility, in the conducting form, in common organic solvents. The resistivity ϱ(T), of polyaniline (PANI) complexed with camphor sulfonic acid (CSA) exhibits a positive temperature coefficient for 180K 10, ϱ(T,H=0)exp(T−1/4). For samples with ϱ(1.2K)/ϱ(300K) ∼3–5, ϱ(T,H=0) T−β where β≈0.36, consistent with transport in the critical region near the metal-insulator (M-I) boundary, whereas ϱ(T,H=8Tesla) =ϱ0exp[(T0/T)1/4], indicating variable range hopping between localized states with mean localization length, Lc(H=8T)∼100–140A. Thus PANI-CSA is on the (M-I) boundary.
Review of electronic transport models for thermoelectric materials

Thermoelectric devices have gained importance in recent years as viable solutions for applications such as spot cooling of electronic components, remote power generation in space stations and satellites etc. These solid-state devices have long been known for their reliability rather than their efficiency; they contain no moving parts, and their performance relies primarily on material selection, which has not generated many excellent candidates. Research in recent years has been focused on developing both thermoelectric structures and materials that have high efficiency. In general, thermoelectric research is two-pronged with (1) experiments focused on finding new materials and structures with enhanced thermoelectric performance and (2) analytical models that predict thermoelectric behavior to enable better design and optimization of materials and structures. While numerous reviews have discussed the importance of and dependence on materials for thermoelectric performance, an overview of how to predict the performance of various materials and structures based on fundamental quantities is lacking. In this paper we present a review of the theoretical models that were developed since thermoelectricity was first observed in 1821 by Seebeck and how these models have guided experimental material search for improved thermoelectric devices. A new quantum model is also presented, which provides opportunities for the optimization of nanoscale materials to enhance thermoelectric performance. c 2008 Elsevier Ltd. All rights reserved.
Efficient characterization of TSV-to-transistor noise coupling in 3D ICs

A methodology is proposed to characterize TSV induced noise coupling in three-dimensional (3D) integrated circuits. Different substrate biasing schemes (such as a single substrate contact versus regularly placed substrate contacts) and TSV fabrication methods (such as via-first and via-last) are considered. A compact π model is proposed to efficiently estimate the coupling noise at a victim transistor. Each admittance within the compact model is approximated with a closed-form expression consisting of logarithmic functions. The methodology is validated using a 3D transmission line matrix (3D-TLM) method, demonstrating, on average, 4.8% error. The compact model and the closed-form expressions are utilized to better understand TSV induced noise as a function of multiple parameters such as TSV type and placement of substrate contacts.
Measurements of Achievement in Fundamental Skills of Elementary School Children

Abstract Valid and reliable tests were developed for the purpose of measuring selected fundamental skills of children in grades 1 to 6. The skills tested were throwing, catching, kicking, batting, jumping, and running. For each test and each sex an analysis of the difference between mean scores for one grade and the mean scores for the succeeding grade showed an upward trend frmo grade to grade, except between grades 5 and 6. Performance norms were computed on the basis of the obtained results. Percentile ranks were computed for each test according to sex and to grade.
Neutronics and shielding results of the US International Thermonuclear Experimental Reactor blanket trade-off study

Abstract Detailed neutronics and shielding analyses have been performed for the different International Thermonuclear Experimental Reactor (ITER) blanket design options considered in the ITER blanket option trade-off study. The options considered included a self-cooled Li/V option, a helium-cooled Li/V option, ferritic steel designs with helium-cooled first wall and liquid metal (Li or LiPb) cooled blanket, the conceptual design activity (CDA) design option, and a water-cooled 316 stainless steel (SS) non-breeding shield option. Among the tritium breeding blanket design options, the self-cooled Li/V option has the highest breeding potential while the CDA blanket design option has the best shielding performance. Additional shielding improvement is achieved by using a non-breeding SS/H2O shield.
Developing a Commitment to Blood Donation: The Impact of One's First Experience1

The increasing demand for voluntarily donated blood has generated research concerned with the development of commitment to regular blood donation. Taking a developmental perspective, this paper explores the longitudinal impact of background, situational, and dispositional factors measured at one's first donation. Questionnaire responses from a sample of first-time donors are analyzed and logistic regression analysis is employed to predict successive “continuation decisions” (the decisions to donate twice, three times, and four times). Results suggest that factors may change in their magnitude and direction of impact across the donor's career. Externally focused social pressures and rewards are dominant at the early stages and self-originating factors at the later stages. Theoretical and practical implications of the findings are discussed.
The solubility of hydrogen in α-manganese

Abstract The equilibrate-quench-analyze technique has been used to determine the temperature variation of hydrogen solubility in α-manganese in equilibrium with H 2 gas at atmospheric pressure. The solubility curve shows a departure from Arrhenius behavior and the relative partial enthalpy of solution changes sign at ∼ 500 °C. The partial molar enthalpy of the dissolved H atoms, obtained from the solubility data by assuming a single mechanism solution process, varies with temperature in a manner parallel to the paramagnetic susceptibility.