cssi/SciSciGPT-SciSciNet huggingface dataset:
Geometric algorithms for reconfigurable structures

In this thesis, we study three problems related to geometric algorithms of reconfigurable structures. In the first problem, strip folding, we present two universal hinge patterns for a strip of material that enable the folding of any integral orthogonal polyhedron of only a constant factor smaller surface area, and using only a constant number of layers at any point. These geometric results offer a new way to build programmable matter that is substantially more efficient than what is possible with a square N × N sheet of material, which can achieve all integral orthogonal shapes only of surface area O(N) and may use Θ( N2) layers at one point [BDDO10]. To achieve these results, we develop new approximation algorithms for milling the surface of an integral orthogonal polyhedron of genus 0, which simultaneously give a 2-approximation in tour length and an 8/3-approximation in the number of turns. Both length and turns consume area when folding strip, so we build on previous approximation algorithms for these two objectives from 2D milling. In the second problem, maxspan, the goal is to maximize the distance between the endpoints of a fixed-angle chain. We prove a necessary and sufficient condition for characterizing maxspan configurations. The condition states that a fixed-angle chain is in maxspan configuration if and only if the configuration is line-piercing (that is, the line through each of the links intersects the line segment through the endpoints of the chain in the natural order). We call this the Line-Piercing Theorem. The Line-Piercing Theorem was originally proved by [BS08] using Morse-Bott theory and Mayer-Vietoris sequences, but we give an elementary proof based on purely geometric arguments. The Line-Piercing Theorem also leads to efficient algorithms for computing the maxspan of fixed-angle chains. In the third problem, efficient reconfiguration of pivoting tiles , we present an algorithmic framework for reconfiguring a modular robot consisting of identical 2D tiles, where the basic move is to pivot one tile around another at a shared vertex. The robot must remain connected and avoid collisions throughout all moves. For square tiles, and hexagonal tiles on either a triangular or hexagonal lattice, we obtain optimal O( n2)-move reconfiguration algorithms. In particular, we give the first proofs of universal reconfigurability for the first two cases, and generalize a previous result for the third case. We also consider a model analyzed by Dumitrescu and Pach [DP06] where tiles slide instead of pivot (making it easier to avoid collisions), and obtain an optimal O(n2)-move reconfiguration algorithm, improving their O(n3) bound. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
Rabbit muscle phosphofructokinase. Reactivity and function of thiol groups.

Abstract Crystalline phosphofructokinase from rabbit skeletal muscle contains 16 to 18 thiol groups per protomer (93,200 daltons). Six groups reacted immediately with 5,5'-dithiobis-(2-nitrobenzoic acid). Pseudo-first order rate constants of 0.0265, 0.0138, and 0.0082 per min were obtained for the seventh plus eighth, ninth plus 10th, and 11th plus 12th thiol groups, respectively, in 0.025 m glycylglycine buffer, pH 8.0, at 28°. The remaining four to six groups reacted very slowly. All thiol groups reacted with Ellman's reagent in 6 m urea, 4 m guanidine hydrochloride, or 3 mm sodium dodecyl sulfate. The thiol content determined by Ellman's reagent approached the half-cystine content determined by amino acid analysis. In the absence of a denaturing agent, fructose 6-phosphate protected two of the six rapidly reacting thiol groups. In the presence of 4 m urea, fructose 6-phosphate as well as fructose 1,6-diphosphate diminished the rate of reaction of the thiol groups with Ellman's reagent. Fructose 6-phosphate seemed to protect highly reactive groups, whereas fructose 1,6-diphosphate exerted its influence on slowly reacting ones. Phosphofructokinase activity was sensitive to 1 mm iodoacetamide. The substrates fructose 6-phosphate and MgATP offered complete protection against this inhibition while the product fructose 1,6-diphosphate did not. About 60% of the enzymatic activity was lost upon alkylation of six thiol groups per protomer.
Teaching emerging teacher-researchers: examining a district-based professional development course

Using critical constructivism as the theoretical lens, the teacher educator-researcher used practitioner research to systematically examine the experience of PreK-12 teachers in his district-based teacher research professional development course, while also examining his development as a teacher educator. The results of this study showed that, as the teachers made progress toward becoming teacher-researchers, they expressed being empowered by the teacher research process. Moreover, they showed a growing critical awareness in their work, while the teacher educator was challenged to re-examine his conceptions of teacher research. Finally, the teachers faced several important barriers in adopting an inquiry stance in their practice. This research generates both local and global knowledge about teacher research as a form of in-service teacher education.
Single Sea Urchin Phagocytes Express Messages of a Single Sequence from the Diverse Sp185/333 Gene Family in Response to Bacterial Challenge

Immune systems in animals rely on fast and efficient responses to a wide variety of pathogens. The Sp185/333 gene family in the purple sea urchin, Strongylocentrotus purpuratus, consists of an estimated 50 (±10) members per genome that share a basic gene structure but show high sequence diversity, primarily due to the mosaic appearance of short blocks of sequence called elements. The genes show significantly elevated expression in three subpopulations of phagocytes responding to marine bacteria. The encoded Sp185/333 proteins are highly diverse and have central effector functions in the immune system. In this study we report the Sp185/333 gene expression in single sea urchin phagocytes. Sea urchins challenged with heat-killed marine bacteria resulted in a typical increase in coelomocyte concentration within 24 h, which included an increased proportion of phagocytes expressing Sp185/333 proteins. Phagocyte fractions enriched from coelomocytes were used in limiting dilutions to obtain samples of single cells that were evaluated for Sp185/333 gene expression by nested RT-PCR. Amplicon sequences showed identical or nearly identical Sp185/333 amplicon sequences in single phagocytes with matches to six known Sp185/333 element patterns, including both common and rare element patterns. This suggested that single phagocytes show restricted expression from the Sp185/333 gene family and infers a diverse, flexible, and efficient response to pathogens. This type of expression pattern from a family of immune response genes in single cells has not been identified previously in other invertebrates.
Accessibility from Scratch: One Library's Journey to Prioritize the Accessibility of Electronic Information Resources

The increased development and use of electronic and information technology in higher education raises questions about accessibility for individuals with disabilities. In academic libraries, providing accessible electronic information resources ensures equal access and opportunity to information. This article provides a contextual understanding of accessibility in higher education as well as strategies for evaluating, negotiating, and procuring accessible electronic resources licensed through third party vendors.
Aging and aortic impedance in beagle dogs.

Abstract Previous studies of the effect of aging on aortic impedance have proved inconclusive. Studies in man could be affected by clinically inapparent atherosclerotic effects which cannot be separated from aging effects. Therefore, to more directly examine the role of aging, hemodynamic studies were carried out in awake, resting young and senescent non-atherosclerotic beagles before and after the administration of various vasoactive agents. On separate days graded infusions of a rapid acting β-adrenergic agonist and antagonist (isoproterenol and propranolol), an α-adrenergic agonist and antagonist (phenylephrine and phenoxybenzamine), combined α- and β-adrenergic antagonists (propranolol plus phenoxybenzamine), and a non-specific vasodilator (nitroprusside) were administered. Aortic impedance was calculated from high-fidelity pressure and flow signals using standard Fourier analysis methods. Under baseline conditions no age-associated differences in any of the hemodynamic parameters were determined to be likely. The only significant age-associated difference in response was to graded doses of isoproterenol wherein there was a larger increase in flow and a greater decrease in resistance in the young compared to the senescent dogs. There were no age-associated differences in response to any of the other drugs. Thus, these data are further evidence in an intact circulation for an age-associated decrease in another β-adrenergically mediated response.
Mechanisms of Ca2+ antagonism in imipramine-induced toxicity of isolated adult rat cardiomyocytes.

Abstract Classic explanations of cyclic antidepressant toxicity often focus on Na+channel blockade; however, cyclic antidepressant toxicity often causes decreased myocardial contractile function. The present experiments first examine inhibition of cytosolic Ca2+signals by imipramine. Second, the experiments test if alkalinization prevents the inhibition of Ca2+signals. Cardiomyocytes from adult rat hearts were loaded with fura-2 dye, and intracellular calcium, [Ca2+]i, was quantified using ratio fluorescence techniques. Changes in [Ca2+]Iwere induced by electrical pacing, depolarization with KCl (84 mM), or treatment with caffeine (10 mM). Imipramine (10–30 μM) inhibited [Ca2+]itransients in electrically paced cardiomyocytes. Imipramine (7.5–30 μM) also inhibited Ca2+signals in KCl depolarized cells. These inhibitory effects were similar to those observed with nisoldipine (100–2000 nM), a selective l -channel blocker. The rise in [Ca2+]ithat was triggered with caffeine (10 mM) was not significantly changed by imipramine (30 μM). Inhibition of KCl-induced Ca2+signals by imipramine was prevented by alkalinization of the medium (tris(hydroxymethyl)aminomethane, pH 7.6), but not by elevation of extracellular sodium to 170 mM. Alkalinization was effective in the presence of HOE642, a selective Na+/H+(NHE) subtype 1 inhibitor. These data show that imipramine causes Ca2+antagonism in heart cells which is independent of sarcoplasmic reticulum Ca2+, and that alkaline treatment prevents this Ca2+antagonism rather than stimulating an alternate source of Ca2+via Na+/H+and subsequent Na+/Ca2+exchange.
Spontaneous Posterior Iliac Crest Regeneration Enabling Second Bone Graft Harvest; A Case Report:

We present a case of a revision spinal fusion in which successful bone graft reharvesting was performed from the posterior iliac crest 4 years after initial intracortical harvesting. To date, only anterior iliac crest regeneration has been reported in orthopedic trauma patients. A 70-year-old man with a history of two prior instrumented lumbar fusion operations developed thoracolumbar kyphosis junctional to the lumbosacral fusion mass. His first operation was an instrumented posterolateral lumbar fusion L1 to L5, where bone graft was harvested from the right iliac crest using the intracortical harvesting technique. The second procedure was performed 18 months later and consisted of an extension of the fusion to the sacrum due to L5–S1 level derived symptoms. The bone graft for this procedure was taken with the same technique from the left iliac crest. The development of thoracolumbar junctional kyphosis necessitated the third operation, which consisted of a same-day anterior–posterior extension of the fusion to T10. Prior to this third procedure, a spinal computer tomography was performed that documented regeneration of the cancellous bone in the right iliac crest. This permitted reharvesting of almost 40 ml of cancellous bone using the intracortical bone harvesting technique from the right iliac crest. Histological analysis showed mature bone. Cancellous bone regeneration and restoration of the local anatomy of the ilium are possible after intracortical bone harvesting. This regeneration can provide autologous bone graft to assist fusion in subsequent operations.
Common volatility and volatility spillovers between U.S. and Eurodollar interest rates: Evidence from the futures market

Abstract U.S. Treasury bill and Eurodollar futures are employed to investigate volatility spillovers between U.S. and Eurodollar interest rates. The paper shows that both interest rates follow a GARCH process but they do not share a common volatility factor. A bivariate EGARCH model that allows for the asymmetric volatility influence of the interest rate differential between markets (the TED spread), as well as that of the domestic market, is used to analyze the volatility spillovers between markets. Results show that the lagged TED spread change is the driving force of the volatility process.
Nordihydroguaiaretic acid (NDGA) inhibits the IGF-1 and c-erbB2/HER2/neu receptors and suppresses growth in breast cancer cells.

Nordihydroguaiaretic acid (NDGA) is a phenolic compound isolated from the creosote bush Larrea divaricatta that has anti-cancer activities both in vitro and in vivo. We can now attribute certain of these anti-cancer properties in breast cancer cells to the ability of NDGA to directly inhibit the function of two receptor tyrosine kinases (RTKs), the insulin-like growth factor receptor (IGF-1R) and the c-erbB2/HER2/neu (HER2/neu) receptor. In MCF-7 human breast cancer cells, low micromolar concentrations of NDGA inhibited activation of the IGF-1R, and downstream phosphorylation of both the Akt/PKB serine kinase and the pro-apoptotic protein BAD. In mouse MCNeuA cells, NDGA also inhibited ligand independent phosphorylation of HER2/neu. To study whether this inhibitory effect in cells was due to a direct action on these receptors, we studied the IGF-1-stimulated tyrosine kinase activity of isolated IGF-1R, which was inhibited by NDGA at 10 μM or less. NDGA was also effective at inhibiting autophosphorylation of the isolated HER2/neu receptor at similar concentrations. In addition, NDGA inhibited IGF-1 specific growth of cultured breast cancer cells with an IC50 of approximately 30 μM. NDGA treatment (intraperitoneal injection 3 times per week) also decreased the activity of the IGF-1R and the HER2/neu receptor in MCNeuA cells implanted into mice. This inhibition of RTK activity was associated with decreased growth rates of MCNeuA cells in vivo. These studies indicate that the anti-breast cancer properties of NDGA are related to the inhibition of two important RTKs. Agents of this class may therefore provide new insights into potential therapies for this disease.
Complementary Hydrogen-Bonded Thermoreversible Polymer Networks with Tunable Properties

Complementary hydrogen bonded cross-linked polymer networks based on two distinct hydrogen bonding recognition motifs have been synthesized by using a combination of ring-opening metathesis polymerization and hydrogen bonding interactions and were subsequently characterized in solution using rheometry. The hydrogen bonding recognition units were based on either three-point cyanuric acid−2,4-diaminotriazine or six-point cyanuric acid−Hamilton wedge interactions. Through the addition of “ditopic cross-linking agents”, the polymer scaffold, which was functionalized with cyanuric acid functional groups, was noncovalently cross-linked in solution through complementary interchain hydrogen bonding interactions. The extent of cross-linking could be controlled by varying the amount of the cross-linking agent added. These networks are thermally reversible and have highly tunable mechanical properties that are controlled by the molecular structure of the cross-linking agent. While the addition of the Hamilton wedge ...
Bidirectional operant conditioning of heart rate in rats with sucrose reward

Abstract Sucrose was used to reinforce heart rate (HR) increases in one group of unrestrained rats and to reinforce decreases in another. A third group received noncontingent sucrose presentations, and a fourth was presented with an empty dipper. After 10 conditioning sessions HR, as measured by changes in tonic levels, was significantly greater in the Fast group than in the Noncontingent group, which in turn maintained significantly higher levels than the Slow group. There was no difference between the Noncontingent and No-sucrose groups. Behavioral observations indicated that the Fast animals increased the percentage of time spent in such high-HR categories as rearing and walking; however, there were no corresponding systematic decreases in the Slow animals. Moreover, the Fast and Slow groups differed significantly with regard to the HRs associated with five behavioral categories. The overall pattern of results suggests that some degree of cardiospecific effect may have been exerted by the operant contingencies.
Identification of a copper complex-forming fraction of pyocyanine.

Abstract Earlier work showed that the extract mixture obtained from Pseudomonas aeruginosa , usually referred to as pyocyanine, polymerized with copper to form characteristic fibers. We have studied this partially purified extract and now find it to have spectral and chromatographic properties of 1-hydroxyphenazine. It is concluded that the substance in the pyocyanine mixture which polymerizes with copper is 1-hydroxyphenazine.
Economica Coase Lecture Reference Points and the Theory of the Firm

I argue that it has been hard to make progress on Coase's theory of the firm agenda because of the difficulty of formalizing haggling costs. I propose an approach that tries to move things forward using the idea of aggrievement costs, and apply it to the question of whether a transaction should be placed inside a firm (in-house production) or in the market place (outsourcing).
Recent reconstructions of blake's Milton and Milton: A poem

(1976). Recent reconstructions of blake's Milton and Milton: A poem. Milton and the Romantics: Vol. 2, No. 1, pp. 1-10.
Analysis of acceleration control loops of a synchrotron

Abstract For beam control during acceleration, it is conventional to derive the frequency from an external reference, be it a field marker or an external oscillator. In addition phase and radial feedback loops are also provided to ensure the phase stability, radial position and emittance integrity of the beam. From the fundamental synchrotron oscillation equations, a unified beam control model has been derived using the Laplace transformation method. The open and closed loop behaviors of both feedback controls and their responds under the possible frequency, phase and radius errors are studied. The stability of the loops is investigated under a wide range of variations of the gain and time delays. Actual system performance of the AGS Booster is analyzed and compared with commissioning experiences. Such analysis is useful for setting design criteria and tolerances for new proton synchrotrons.
Biomolecular applications of single-molecule measurements: kinetics and dynamics of a single-enzyme reaction

In this work we describe preliminary experiments in which we have used ultra-sensitive fluorescence microscopy to observe the dynamics of individual enzyme molecules acting upon a substrate. The enzyme, (beta) -galactosidase from E.coli, is specifically immobilized onto a glass substrate while maintaining its functionality. The immobilized protein degrades a fluorogenic substrate to produce a fluorescent product, whose generation can be observed in real time. Individual copies of (beta) -galactosidase can be observed for many minutes, allowing the measurement of a large number of successive substrate turnover events. A rudimentary analysis of these turnovers using autocorrelation functions is presented, and a strong heterogeneity in reaction rates between different molecules is observed. In addition, the challenges inherent in successful surface immobilization of proteins for single-molecule experiments are discussed.
The Role of Shearwise and Transverse Quasigeostrophic Vertical Motions in the Midlatitude Cyclone Life Cycle

Abstract The total quasigeostrophic (QG) vertical motion field is partitioned into transverse and shearwise couplets oriented parallel to, and along, the geostrophic vertical shear, respectively. The physical role played by each of these components of vertical motion in the midlatitude cyclone life cycle is then illustrated by examination of the life cycles of two recently observed cyclones. The analysis suggests that the origin and subsequent intensification of the lower-tropospheric cyclone responds predominantly to column stretching associated with the updraft portion of the shearwise QG vertical motion, which displays a single, dominant, middle-tropospheric couplet at all stages of the cyclone life cycle. The transverse QG omega, associated with the cyclones’ frontal zones, appears only after those frontal zones have been established. The absence of transverse ascent maxima and associated column stretching in the vicinity of the surface cyclone center suggests that the transverse ω plays little role i...
Experimental studies of trailing-edge conditions on an oscillating airfoil at frequency parameters of up to one

This paper describes an investigation to find the range of reduced frequencies over which the classical Kutta-Joukowsky condition is valid and the nature of deviations beyond this range. An NACA 64A010 airfoil with a 15-cm chord is supported between the side walls of a 25-cm x 35-cm low-speed wind tunnel and oscillated over reduced frequencies ranging from 0.05 to 1.2. The experimentally determined loading near the trailing edge is measured and compared with unsteady incompressible small-disturbance theory. Experimental data are obtained both with and without a boundary-layer trip. It is observed that application of the Kutta-Joukowsky condition in the theoretical analysis is valid below a reduced frequency of about 0.6 in predicting the loading in the trailing-edge region. At reduced frequencies beyond 0.8, the predicted results underestimate the measured loading near the trailing edge, and the deviations increase further with reduced frequency. Similarly, the experimental phase angle of the loading in the trailing-edge region agrees reasonably with the linear theory up to k = 0.8 but lags the predicted value beyond k = 0.8.
The use of heterogeneous and epitaxial nucleants to promote the growth of protein crystals

Fifty different mineral samples were tested as potential heterogeneous or epitaxial nucleants for four commonly crystallized proteins. It was found, using conventional protein crystallization techniques, that for each protein there was a set of mineral substrates that promoted nucleation of crystals at lower critical levels of supersaturation than required for spontaneous growth. In at least one case, the growth of lysozyme on the mineral apophyllite, it was shown by lattice analysis and X-ray diffraction that the nucleation and growth of the protein crystal on the mineral was likely to be truly epitaxial.
Transcriptional Regulation of Fatty Acid Translocase/CD36 Expression by CCAAT/Enhancer-binding Protein α

Fatty acid translocase (FAT/CD36) plays an important role in facilitating long chain fatty acid transport. FAT/CD36 gene deletion protects mice from high fat diet-induced obesity. In this study we have investigated the regulatory mechanism of FAT/CD36 expression at the transcription level. FAT/CD36 expression was activated during 3T3-L1 adipocyte differentiation, and FAT/CD36 protein levels were positively correlated with CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ. However, a negative correlation was detected between FAT/CD36 and C/EBPβ. Overexpression of C/EBPα or C/EBPβ increased FAT/CD36 mRNA and protein levels in several types of cells. Restoration of C/EBPα or C/EBPβ expression in C/EBPα- or C/EBPβ-deficient mouse embryonic fibroblasts increased FAT/CD36 expression. However, in mouse embryonic fibroblasts C/EBPα was a more potent activator of FAT/CD36 expression than was C/EBPβ. Expression of C/EBPα robustly increased FAT/CD36 proximal promoter-directed luciferase expression in human embryonic kidney 293 cells. A C/EBP-responsive element was identified in the FAT/CD36 promoter by using 5′ and specific site mutations. The binding of C/EBPα in the FAT/CD36 promoter was detected by chromatin immunoprecipitation in 3T3-L1 adipocytes. These results demonstrated that C/EBPα regulates FAT/CD36 gene expression at the transcriptional level.
Neuronal markers expression of NGF-primed bone marrow cells (BMCs) transplanted in the brain of 6-hydroxydopamine and ibotenic acid lesioned littermate mice

In the present study, we aim to show that non-adherent bone marrow cells (BMCs) express TrkA, the nerve growth factor (NGF) receptor, and that addition of NGF promotes the survival and neuronal commitment of BMC transplanted into the experimentally injured brain of littermates mice. Immunohistochemical analysis revealed that transplanted BMCs express tyrosine hydroxylase (TH) in proximity of the damaged dopaminergic tissues and choline acetyltransferase (ChAT) in the lesioned cholinergic regions. These results suggest that NGF supports the survival and differentiation of uncommitted BMCs and concurs with other local environmental signals to promote the expression of neuronal markers in these cells. The possible functional significance of these observations will be discussed.
Usefulness of Transesophageal Echocardiography in Predicting Mortality and Morbidity in Stroke Patients Without Clinically Known Cardiac Sources of Embolus

Abstract This study tested the hypothesis that stroke patients without a cardiac source of embolism suspected by clinical examination can be risk stratified by transesophageal echocardiography. Forty ischemic stroke patients without atrial fibrillation, prosthetic valves, ejection fraction
Detection and characterization of high-velocity impact damage in advanced composite plates using multi-sensing techniques

Abstract Advanced composites are increasingly used in aerospace, naval, and automotive vehicles due to their high specific strength and stiffness. However, the mechanical properties of composite materials may degrade severely in the presence of damage. Damage due to impact in composite plates is often difficult to detect using any single technique. In this paper, the use of multiple sensing techniques to characterize high-velocity impact damage in advanced composites is reported. Broadband wave-based acoustic emission (AE) sensors are used to capture wave signals due to impact while shearography and ultrasonic (UT) immersion techniques are used to assess location and extent of damage after the impact. Five 48-ply [0/+45/90/−45]6s laminated AS4/PEEK composite plates were used as test specimens. Shearography images of all five test specimens were taken before impact testing to detect any pre-existing internal damage from fabrication. Three broadband AE sensors were mounted on the surface of the composite plates to capture the AE signals due to impact. A 3/8-inch diameter stainless steel ball fired from a gas gun facility was used as a projectile to inflict damage to the composite plates. The AE signals were instantaneously acquired during the impact tests and stored in a computer. The AE signals show existence of both the extensional and flexural modes, with extensional modes typically showing first. AE energy also increases to a threshold as the kinetic energy of impact increases. Shearography fringe patterns show existence of damage and this is confirmed and quantified with C-scan images from the UT immersion test. There is good correlation between AE parameters such as AE energy, AE amplitude, and AE count with impact energy and with damage on the composite plates. Due to the low contrast of the shearograms, UT C-scans are used to show extent of damage. This research demonstrates how multiple sensing techniques can be used to characterize high-velocity impact damage in advanced composites.
Immiscible CO2‐H2O fluids in the shallow crust

The significance of a single CO2-H2O fluid phase is well known for metamorphic systems, and CO2-H2O immiscibility is explicit in fluid inclusion literature, especially regarding hydrothermal ores. Complex multiphase CO2-H2O behavior exists over wide temperature and pressure ranges overlapping other important geochemical processes. The character and physical-chemical properties of multiple phases possible for CO2 and H2O, and the potential impact of these coexisting phases on geochemical processes in the crust, are not broadly appreciated. We propose that immiscible supercritical CO2 fluid and a liquid rich in H2O coexist in the shallow crust, to 400°C and 300 MPa, and that interactions among the two fluids and host rock are significant processes that produce recognizable geochemical and textural evidence. Supercritical CO2 fluids bring potential complexity to fluid-rock systems by influencing aqueous reactions via carbonic acid equilibria, penetrating complex geometries inaccessible to aqueous fluid, and dissolving and redistributing metals as organometallic compounds. The distal margin of a contact metamorphic aureole is one example we discuss in which interaction between two disparate CO2-H2O fluids controls H2O activity and the progress and distribution of metamorphic hydration reactions. In another example, supercritical CO2 produces acidity, carbonate saturation, and silica supersaturation in brine. Separation and emplacement of this brine into a rock-dominated system buffered to neutral pH enhances precipitation of carbonates and quartz, chalcedony, or amorphous silica in veins. Other possible examples of CO2-H2O fluid immiscibility coupled with multiphase fluid-rock interactions are clay desiccation, diagenetic and postdiagenetic silicate reactions, origin and distribution of carbonate cements in sedimentary basin sandstones, fluid-mass transfer, and anthropogenic CO2 sequestration.
Timing analysis with nonseparable statistical and deterministic variations

Statistical static timing analysis (SSTA) is ideal for random variations but is not suitable for environmental variations like Vdd and temperature. SSTA uses statistical approximation, according to which circuit timing is predicted accurately only for highly probable combinations of variational parameters. SSTA is not able to handle accurately deterministic sources of variation like supply voltage. This paper presents a novel technique for modeling nonseparable deterministic and statistical variations in single timing run.
Coastal marine eutrophication: A definition, social causes, and future concerns

Abstract There is a need in the marine research and management communities for a clear operational definition of the term, eutrophication. I propose the following: This definition is consistent with historical usage and emphasizes that eutrophication is a process, not a trophic state. A simple trophic classification for marine systems is also proposed: Various factors may increase the supply of organic matter to coastal systems, but the most common is clearly nutrient enrichment. The major causes of nutrient enrichment in coastal areas are associated directly or indirecdy with meeting the requirements and desires of human nutrition and diet. The deposition of reactive nitrogen emitted to the atmosphere as a consequence of fossil fuel combustion is also an important anthropogenic factor. The intensity of nitrogen emission from fertilizer, livestock waste, and fossil fuel combustion varies widely among the countries of the world. It is strongest in Europe, the northeastern United States, India/Pakistan, Jap...
Object-memory evaluation for prospective detection of dementia in normal functioning elderly: predictive and normative data.

In a prospective study of dementia in initially normal functioning elderly, a brief form of the Fuld Object-Memory Evaluation (OM) was administered to 474 cognitively normal community-residing volunteers aged 75-85 at baseline and annually thereafter. Seventy-two subjects later became demented. Memory test data from the last annual evaluation before cognitive change was noted were available for 56. Although the entire population recalled 7.28 (SD = 1.33) of the 10 objects on Trial 1 of the test at baseline, these 56 subjects recalled only 5.96 (SD = 1.85). When recall of 6 or fewer objects was used as a predictor, the OM test identified 32 of the 56 who subsequently became demented. Compared to an estimated base rate of 15% for dementia, the predictive value of a positive test (PV+) was 39%, and that of a negative test (PV-) was 89%. With a cutoff of 5 or fewer items recalled, the PV+ rose to 59% and the PV- was 94%. Although the OM test was only moderately sensitive to incipient dementia (.57), it was fairly specific (.84), and lowering the cutoff to 5 increased the specificity to .96. Memory testing would therefore seem to hold promise as a predictor of dementia in cognitively normal elderly.
A proposal for quantitative reporting of comparative judgments.

(1947). A Proposal for Quantitative Reporting of Comparative Judgments. The Journal of Psychology: Vol. 24, No. 2, pp. 229-235.
Comparison of mechanisms of anemia in mice with sickle cell disease and β-thalassemia: Peripheral destruction, ineffective erythropoiesis, and phospholipid scramblase-mediated phosphatidylserine exposure

Abstract Objectives 1) To study the mechanisms of anemia, erythroid hyperplasia, and red blood cell (RBC) clearance in murine models of sickle cell disease (Sickle) and β-thalassemia (Th1/Th1); 2) To determine the contribution of the phospholipid scramblase enzyme to phosphatidylserine (PS) exposure and RBC death in Sickle and Th1/Th1 mice. Methods We used a combination of flow-cytometric analysis and assays for phospholipid remodeling to determine the extent and sites of erythroid hyperplasia, PS exposure, and cell death. Results 1) Sickle RBCs have a much shorter half-life than Th1/Th1 RBCs (0.8 days vs 11 days). A significant proportion of Th1/Th1 peripheral reticulocytes mature into erythrocytes, however, ∼fivefold fewer Sickle reticulocytes mature. While erythroid hyperplasia exists in both Sickle and Th1/Th1 mice, Th1/Th1 produce fourfold more RBCs than necessary to maintain steady state, while Sickle produce no excess RBCs. 2) 61% of Sickle and 34% of Th1/Th1 RBCs are scramblase + as measured by internalization assays of the fluorescent phospholipid NBD-PC. The majority of NBD-PC + RBCs are also annexin-V + , supporting a mechanistic link between scramblase activity and PS exposure. A proportion of both reticulocytes and older RBCs in Sickle and Th1/Th1 mice have active scramblase, and the degree of scramblase activation in these strains correlates with the propensity for RBC death. Conclusions Sickle and Th1/Th1 mice are both anemic, with significant erythroid hyperplasia. Th1/Th1 mice display ineffective erythropoiesis while Sickle mice show rapid peripheral destruction of RBCs. PS exposure and phospholipid scramblase activity serve as markers of RBCs with altered phospholipid asymmetry and greater propensity for cell death.
Bond-order-bond-energy correlations

Abstract A practical procedure for determining the relative strengths of chemical bonds is presented. It is shown, for diatomic and polyatomic molecules, that bond strengths correlate directly with bond orders calculated from force constants and bond lengths. The latter two properties can be obtained either experimentally or computationally.
Interval estimation of the ordered means of two normal populations based on hybrid estimators

SUMMARY The interval estimation of ordered means of two normal populations based on a statistic which is sometimes the pooled sample mean and sometimes the maximum, or minimum, of the sample means, depending on whether the difference between the two sample means is small or large, when the two sample means have a common known variance is considered. The coverage probability of this procedure is derived and its behaviour is investigated. Comparisons with other procedures are made.
Correlation of thicknesses of superficial spreading malignant melanomas and ages of patients.

In a prospective study of 455 consecutive patients with superficial spreading malignant melanomas entered into the data base of the Melanoma Cooperative Group of New York University Medical Center, it was found by linear-regression analysis that there is a statistically significant (p = 0.005) positive correlation between the ages of the patients and the thicknesses of their lesions. Although the reasons for the correlation between ages and thicknesses are not certain, several possible explanations were considered, namely: (1) the greater prevalence of superficial spreading malignant melanomas in the aged on the lower limbs where thicker lesions were present in our patients, (2) the altered skin of the elderly, which may favor deeper penetration by these neoplasms, (3) impaired immunologic responses in the aged, (4) the delay in diagnosis of malignant melanomas in the elderly because of obscuration of them by numerous benign pigmented lesions that frequently develop with aging, and (5) lesser concern of the elderly with their physical appearances in particular and medical problems in general.
Clamped-filament elongation model for actin-based motors.

Although actin-based motility drives cell crawling and intracellular locomotion of organelles and certain pathogens, the underlying mechanism of force generation remains a mystery. Recent experiments demonstrated that Listeria exhibit episodes of 5.4-nm stepwise motion corresponding to the periodicity of the actin filament subunits, and extremely small positional fluctuations during the intermittent pauses [S. C. Kuo and J. L. McGrath. 2000. Nature. 407:1026-1029]. These findings suggest that motile bacteria remain firmly bound to actin filament ends as they elongate, a behavior that appears to rule out previous models for actin-based motility. We propose and analyze a new mechanochemical model (called the "Lock, Load & Fire" mechanism) for force generation by means of affinity-modulated, clamped-filament elongation. During the locking step, the filament's terminal ATP-containing subunit binds tightly to a clamp situated on the surface of a motile object; in the loading step, actin.ATP monomer(s) bind to the filament end, an event that triggers the firing step, wherein ATP hydrolysis on the clamped subunit attenuates the filament's affinity for the clamp. This last step initiates translocation of the new ATP-containing terminus to the clamp, whereupon another cycle begins anew. This model explains how surface-tethered filaments can grow while exerting flexural or tensile force on the motile surface. Moreover, stochastic simulations of the model reproduce the signature motions of Listeria. This elongation motor, which we term actoclampin, exploits actin's intrinsic ATPase activity to provide a simple, high-fidelity enzymatic reaction cycle for force production that does not require elongating filaments to dissociate from the motile surface. This mechanism may operate whenever actin polymerization is called upon to generate the forces that drive cell crawling or intracellular organelle motility.
Nuclear targeted delivery of macromolecules to retina and cornea

Background Cell-penetrating peptides (CPPs) can deliver molecules into cells by binding and penetrating the plasma membrane. However, the majority of CPPs get trapped in endosomes, resulting in degradation of the cargo molecule and inefficient delivery to the nucleus. The present study investigates the potential use of a nucleolin binding peptide (NBP) for the delivery of macromolecules including fluorophores, recombinant protein and DNA to the nuclei of ocular tissues in vivo. Methods Fluorescent dyes covalently linked to NBP or NBP-green fluorescent protein fusion protein were injected intravitreally or subretinally or topically applied to the cornea. Frozen sections were prepared for quantification of transduction. Delivery of plasmid DNA was studied using luciferase and LacZ DNA compacted with pegylated NBP. Levels of luciferase were quantified, and LacZ expression was localized in ocular tissues. Results We found that NBP-directed fluorophores exhibited retinal and corneal transduction. Subretinal injection transduced cell types throughout the retina, including photoreceptors, retinal pigment epithelium and neuronal cells. Intravitreal injection transduced neuronal cells in the retina, as well as cells in the cornea. Topically applied NBP lead to transduction of the superficial epithelial layer of the cornea. NBP localized to the nucleus upon exogenous application in vivo. Pegylated NBP nanoparticles significantly improved delivery and expression of transgenes over DNA alone without any measureable toxicity. Conclusions The results obtained in the present study demonstrate that NBP can deliver small and large molecules into retinal and corneal cells and plasmid DNA into retinal cells and hence may be useful for the delivery of therapeutics to the eye. Copyright © 2011 John Wiley & Sons, Ltd.
Empirical constraints on the titanite (U–Th)/He partial retention zone from the KTB drill hole

We analyzed (U–Th)/He ages of titanite from both the initial pilot hole (4 km depth) and the main drill-hole (9 km depth) of the German Continental Deep Drilling Project (KTB), to empirically evaluate the titanite (U–Th)/He partial retention zone (HePRZ) and laboratory helium diffusion data. Laser (U–Th)/He ages on single titanite fragments from the KTB drill hole, uncorrected for α emission, range from ∼94 to ∼2 Ma with reproducibility better than ±9%. Nearly invariant titanite (U–Th)/He ages, concordant with reported apatite fission track data, suggest that rocks from the upper ∼3 km of the KTB drill hole rapidly cooled from temperatures >200 to <110 °C between ∼75 and 85 Ma, followed by protracted cooling. Below ∼3 km, mean titanite (U–Th)/He ages decrease systematically with increasing borehole depth and down-hole temperature in a pattern similar to the titanite HePRZ predicted on the basis of laboratory-determined He diffusivities. Our results demonstrate that experimental titanite He diffusion data are applicable in the natural setting and that titanite (U–Th)/He thermochronometry provides a means to reliably reconstruct and quantify thermal histories between ∼100 and 180 °C, bridging the temperature ranges constrained by other techniques such as ^(40)Ar/^(39)Ar K-feldspar multi-diffusion domain modeling (350–150 °C) and apatite fission track dating (<110 °C).
The concept of information in ordinary discourse

Abstract The concept of information as it is actually used in ordinary discourse is elucidated, using philosophical methods of conceptual analysis. Five essential properties and four derivative properties of the phenomenon of information are identified. This concept of information is contrasted with several proposed concepts in the literature of information theory, communication theory, and Information Science.
Recognizing the P4-structure of a tree

The P4-structure of a graphG =(V,E) is a hypergraphH = (V,F) such that, for every hyperedgeA inF, the cardinality ofA is four and the subgraph of G induced byA is a path. It is proved in this paper that the P4-structure of a tree can be recognized in polynomial time.
Corruption as a gamble

Abstract In the following model of corruption, a simple game is set up whose players are a government official granting a permit, conditional on a test, and a candidate requesting the permit. The game is solved under different assumptions as to the information sets of the players: perfect information, asymmetric information and imperfect information on both sides. In the latter case, after characterizing the solution and presenting some important comparative-statics results, the paper moves on to show the emergence of multiple equilibria in corruption, illustrating the interaction of corruption at different hierarchical levels of an administration.
An experimental study of the effect of turbulent mixing on the selectivity of competing reactions

An experimental study of the effect of turbulent mixing on the selectivity of a parallel-consecutive reaction system (A + B R; R + B S) has been carried out in an unmixed feedstream (multijet) tubular reactor. Fluid mechanical characterization of the reactor by pulsed ultrasound Doppler velocimetry reveals that the mean and rms velocity fields are nearly constant over eight-ninths of the reactor length. Axial profiles of mean product concentration (R and S) have been measured spectro-photometrically with a fiber-optic probe under constant hydrodynamic conditions but with variable feed concentration conditions. The concentration profiles (particularly the S profile) show very large deviations from the perfect mixing (classical plug flow reactor) limit. These data provide a good basis for discriminating among the many models of mixing and reaction available in the literature. This is demonstrated with two examples: the four-environment model, which fits the data well, and the interaction by exchange with the mean model, which does not.
Murine Neural Stem/Progenitor Cells Protect Neurons against Ischemia by HIF-1α–Regulated VEGF Signaling

Focal cerebral ischemia following middle cerebral artery occlusion (MCAO) stimulates a robust cytogenic response from the adult subventricular zone (SVZ) that includes massive proliferation of neural stem/progenitor cells (NSPCs) and cellular migration into the injury area. To begin to explore beneficial roles of NSPCs in this response, we investigated the ability of embryonic and postnatal NSPCs to promote neuronal survival under conditions of in vivo and in vitro ischemia. Intracerebral transplantation of NSPCs attenuated neuronal apoptosis in response to focal ischemia induced by transient MCAO, and prevented neuronal cell death of cortical neurons in response to oxygen-glucose deprivation (OGD) in culture. NSPC-mediated neuroprotection was blocked by the pharmacological inhibitors of vascular endothelial growth factor (VEGF), SU1498 and Flt-1Fc. Embryonic and postnatal NSPCs were both intrinsically resistant to brief OGD exposure, and constitutively expressed both hypoxia-inducible factor 1α (HIF-1α) transcription factor and its downstream target, VEGF. Genomic deletion of HIF-1α by Cre-mediated excision of exon 2 in NSPC cultures resulted in >50% reduction of VEGF production and ablation of NSPC-mediated neuroprotection. These findings indicate that NSPCs promote neuronal survival under ischemic conditions via HIF-1α-VEGF signaling pathways and support a role for NSPCs in promotion of neuronal survival following stroke.
Mechanism of light production in metal-insulator-semiconductor diodes; GaN:Mg violet light-emitting diodes

Abstract The mechanism of electroluminescence in MIN GaN:Mg violet light-emitting diodes was analyzed by considering observed structural features of the diodes as well as their electrical and optical characteristics. Comparison of the observed I – V characteristic, including dependence upon temperature and upon film thickness, with all possible mechanisms for conduction in insulators lead to a proposed conduction mechanism of quantum mechanical tunneling, with the I – V characteristic being well represented by the Fowler-Nordheim equation. The proposed mechanism of light production involved impact ionization of luminescent centers near the i - n junction, with subsequent radiative recombination. This proposed mechanism was supported by measurements of carrier multiplication in the device and a steep voltage gradient at the i - n junction. The impact ionization process occurs in discrete regions coincident with sub-grain boundaries in the GaN film.