cssi/SciSciGPT-SciSciNet huggingface dataset:
Phylogenetic Analysis of Plant Basic Helix-Loop-Helix Proteins

The basic helix-loop-helix (bHLH) family of proteins is a group of functionally diverse transcription factors found in both plants and animals. These proteins evolved early in eukaryotic cells before the split of animals and plants, but appear to function in 'plant-specific' or 'animal-specific' processes. In animals bHLH proteins are involved in regulation of a wide variety of essential developmental processes. On the contrary, bHLH proteins have not been extensively studied in plants. Those that have been characterized function in anthocyanin biosynthesis, phytochrome signaling, globulin expression, fruit dehiscence, carpel and epidermal development. We have identified 118 different bHLH genes in the completely sequenced Arabidopsis thaliana genome and 131 bHLH genes in the rice genome. Here we report a phylogenetic analysis of these genes, including 46 genes from other plant species and a classification of these proteins into 15 distinct plant clades. Results imply a polyphyletic origin for the plant bHLH proteins related only by their bHLH DNA binding motif. We suggest that plant bHLH proteins are under weaker selective constraints than their animal counterparts and that lineage specific expansions and subfunctionalization have fashioned regulatory proteins for plant specific functions.
Some Recent Results in Heuristic Search Theory

The paper summarizes recent analytical investigations of the mathematical properties of heuristics and their influence on the performance of common search techniques. The results are reported without proofs together with discussions of motivations and interpretations. The highlights include the following: the optimality of A*; relations between the precision of the heuristic estimates and the average complexity of the search; comparisons of the average complexities of A* and BACKTRACKING; procedures for comparing and combining nonadmissible heuristic functions; the influence of the weight w (in f = (l - w) g + wh) on the complexity of A*; the pruning power of alphabeta, SSS*, and SCOUT; the effect of successor ordering on search complexity, and the effect of search depth of the quality of decisions in game-playing.
Distinguished Fellow An Appreciation of Guy Orcutt

Guy Henderson Orcutt was born and grew up in Michigan, near Detroit, and had established a lifelong curiosity about how things work before he entered high school. His earliest efforts involved electrical devices and experiments, sometimes with explosive effects, but with continuing support and encouragement from his parents. His later efforts, as he progressed from engineering through physics to economics and econometrics, have given several generations of economists new ways to think about economic phenomena and new and better tools for investigating them. Guy has now moved to a new phase of his career and we can confidently expect further insights and inspiration from this distinctive and Distinguished Fellow of our Association. Most of Guy's career has been at four universities: Michigan, where he earned all three degrees, Harvard, Wisconsin, and Yale. In between, he spent periods at MIT, Cambridge University in England, the International Monetary Fund, the World Bank, and The Urban Institute. To me, Guy is several persons rolled into one: inventor, visionary, empiricist, mentor and friend.
Parental Autonomy Support Moderates the Link Between ADHD Symptomatology and Task Perseverance

The current study investigated the moderating role of mother and father autonomy support in the link between youth Attention-Deficit Hyperactivity Disorder (ADHD) symptoms and task perseverance. ADHD symptomatology was assessed using a multi-informant composite of mother, father, and teacher ratings, and youth perseverance and parental support of autonomy were examined using a behavioral observation paradigm (i.e., difficult puzzle task). Results indicated that youth who were rated as exhibiting more symptoms of ADHD persevered less on a difficult puzzle task and that this relationship was moderated by parental level of autonomy support. In the context of high parental autonomy support, the negative relation between ADHD and perseverance became nonsignificant. Findings indicate that supporting youth autonomy may have significant implications for their development and that it would be valuable to aid parents in developing the appropriate skills necessary for them to successfully support their child’s autonomy.
Manufacturability of Electronic Chips

If the size of features on a microchip are of order of or smaller than the wavelength of the light used in their manufacture, manufacturability of the chip suffers due to diffraction. The degrading effect of diffraction can be handled by biasing masks used for patterning the chips and by optimizing optical system (stepper) parameters. In this paper, algorithms for biasing masks and optimizing stepper parameters are designed and implemented. The algorithms are efficient and feasible for industrial size masks.
The aluminum hypothesis of Alzheimer's disease: A personal view based on microprobe analysis

Abstract Although bulk aluminum analyses have produced conflicting results, microprobe analysis have demonstrated focal accumulations within the neurofibrillary tangle-bearing neurons associated with Alzheimer's disease. Similar accumulations have been identified within the numerous tangle-bearing neurons encountered in the brains of the indigenous natives of the island of Guam who suffer from amyotrophic lateral sclerosis and parkinsonism with dementia. These findings are discussed in relationship to environmental factors and the inherent integrity of barrier systems which insure isolation of the central nervous system from those environmental sources of aluminum.
A critical look at expert systems for business information applications

This paper argues that, contrary to the expectations of researchers, academics and practitioners, current expert systems (ES) for business information and decision making applications arc actually quite primitive and fall disturbingly short of claims of intelligence. The focus of the article is a discussion of the problems with expert systems and a realistic assessment of the narrow spectrum of ES successes. The problems seriously detract from the prospects of expert systems as practical enhancements to most present-day business information systems.
Myocardial bridge associated with pacing-induced coronary spasm

In our case, prolonged chest pain, pathologic elevation of cardiac enzymes, and R wave reduction supported the diagnosis of myocardial infarction. However, myocardial necrosis was not responsible for the development of a new Q wave; indeed, the abnormal Q wave rapidly disappeared after PTCA restored coronary bloow flow. Transient pathologic Q waves have been described in ischemic heart disease,1-4 but not in acute myocardial infarction. Some believe that transient Q waves are due to an intraventricular conduction disturbance: while others link the phenomenon to an electrical death of ischemic cells without actual anatomic death.* Whatever the genesis of transient Q waves may be, our report strongly suggests that new Q waves during evolving myocardial infarction may reverse, in the beginning, if coronary reperfusion is obtained. Other findings demonstrate that PTCA reduced tissue damage: (1) ECG showed only temporary abnormalities of T waves and slight loss of R waves amplitude; (2) left ventriculography was normal on discharge; (3) exercise test was negative and the patient remained asymptomatic. In comparison with thrombolytic therapy,6 PTCA offers the advantage of a rapid resolution of both coronary occlusion and residual stenosis. Our report demonstrates that PTCA can be a first-line therapy in evolving myocardial infarction due to subocclusive coronary stenosis, although its use in the presence of total coronary occlusion does not seem justified at this time.
Building bridges within mathematics education: Teaching, research, and instructional design☆

Abstract Within mathematics education, classroom teachers, educational researchers, and instructional designers share the common goals of understanding and improving the teaching and learning of mathematics. Teachers work to help students learn; researchers study how people learn and teach mathematics; and designers develop instructional materials to support teachers and students. Each community (of teachers, of researchers, and of designers) develops its own perspectives, methods, and expertise. Too seldom, however, do practitioners have the opportunity to share their knowledge across communities. This first-person, retrospective case study speaks to the challenges and rewards of building bridges among these three communities by charting the evolution of an instructional activity (using graphing software to explore slope) through four cycles of teaching, research, and design. Initially separate, the three perspectives of teacher, researcher, and designer begin to interact as the worksite moves from the university laboratory to the author's classroom and then to other teachers’ classrooms. Many of these interactions are fruitful, resulting in new insights and strategies that strengthen the final product and inform the practitioner. At the same time, some tensions arise, particularly between teaching and research, highlighting fundamental differences between these fields. Lessons from this case study suggest implications for collaborations among teachers, researchers, and designers.
Complete Solutions and Extremality Criteria to Polynomial Optimization Problems

This paper presents a set of complete solutions to a class of polynomial optimization problems. By using the so-called sequential canonical dual transformation developed in the author's recent book [Gao, D.Y. (2000), Duality Principles in Nonconvex Systems: Theory, Method and Applications, Kluwer Academic Publishers, Dordrecht/Boston/London, xviii + 454 pp], the nonconvex polynomials in $$\mathbb{R}^n$$ can be converted into an one-dimensional canonical dual optimization problem, which can be solved completely. Therefore, a set of complete solutions to the original problem is obtained. Both global minimizer and local extrema of certain special polynomials can be indentified by Gao-Strang's gap function and triality theory. For general nonconvex polynomial minimization problems, a sufficient condition is proposed to identify global minimizer. Applications are illustrated by several examples.
Miscoding of hospital discharges as acute myocardial infarction: Implications for surveillance programs aimed at elucidating trends in coronary artery disease

The current decline in coronary artery disease mortality (CAD) may be a result of a declining population risk or of a declining case-fatality rate. Information on incidence trends for myocardial infarction (MI) could be used to distinguish between these 2 possibilities. Hospital discharge codes for MI (ICDCM-410) could be used as a convenient proxy for incidence trends, provided that coding of hospital discharges is sufficiently accurate. To evaluate the accuracy of medical records coding of patients signed out with an acute MI code (ICDCM-410), we compared them to an independent cardiology surveillance study of all patients with acute MI admitted to a large county teaching hospital. Over a 12-month period, 110 patients were coded as ICDCM-410 by medical records, but only 67 of these were detected by cardiology surveillance. The charts of the 43 patients not detected by surveillance were reviewed. In none of the 43 was evidence of acute MI found. In 28 of the 43, the discharge summaries listed rule out MI or status post-MI readmitted for further diagnostic workup, but were miscoded as ICDCM-410. Twelve of the 43 patients had cardiac arrests but were coded as ICDCM-410, even though there was no evidence of MI. Therefore, erroneous coding of patients as acute MI (ICDCM-410) may conceal a true downward trend in the incidence of CAD.
Modes of methyleneoxy bridging and their effect on tetrahydronaphthalene lignan cytotoxicity.

Dioxatricyclodecane, oxabicyclooctane, and benzodihydropyran derivatives of α-conidendrin (ACON), podophyllotoxin (PT), and sikkimotoxin (SK) were prepared to learn which methyleneoxy bridging modes and arene and aryl substituents coincided with high cytotoxicity. PT-derived dioxatricyclodecane 14 showed in vitro activity at 10-8 M. SK analogue 12 was less active, and ACON analogue 11 was inactive at 10-4 M. In vivo intraperitoneal and subcutaneous activities of 14 were observed. In vitro cytotoxicities were higher for oxabicyclooctanes when hydroxymethyl group and methyleneoxy bridge were cis, as in deoxypicropodophyllin analog 20, rather than trans, as in PT analogue 5. Acetylation of the hydroxymethyl group of 20 lowered activities, whereas acetylation of 5 increased or lowered activities. Reduction of the hydroxymethyl group of 5 to a methyl group increased cytotoxicities. Molecular dynamics indicated the THN scaffold of benzodihydropyrans was conformationally mobile, but scaffolds of oxabicyclooctane...
Micromechanical behavior of Kevlar-149/S-glass hybrid seven-fiber microcomposites: I. Tensile strength of the hybrid composite

Abstract To understand the mechanism of the ‘hybrid effect’ on the tensile properties of hybrid composites, single fiber type and hybrid microcomposites were fabricated by using Kevlar-149 as the low elongation fiber and S glass fibers as the high elongation fiber, in a DER 331/DER 732 epoxy mixture (70/30, w/w). Kevlar-149 fiber showed a significantly higher tensile strength in the microcomposite than as a single filament. For the hybrid, Kevlar-149 fibers usually broke one by one. A positive hybrid effect for the failure strain but a negative hybrid effect for the strength of the hybrid were observed. Tensile strength of the microcomposites predicted by Monte Carlo simulation agreed with the experimental results reasonably well. The tensile modulus of the hybrid followed the rule of mixture. The fiber/matrix interface properties were investigated by using single fibre pull-out from a microcomposite (SFPOM) test, which showed a significant difference between the interfacial shear strength (IFSS) of Kevlar fiber/epoxy in single-fiber type (SFT) and that in the hybrid at a constant fiber volume fraction, which shortened the ineffective length and contributed to the failure strain increase of Kevlar-149 fibers in the hybrid.
On the frontline: what an optometrist needs to know about myasthenia gravis.

Abstract Background Myasthenia gravis (MG) is an autoimmune disease that affects the voluntary skeletal muscles. It is characterized by transient weakness of the muscles that improves with rest. Muscle weakness involving the eyes can produce signs or symptoms of diplopia, blurred vision, ptosis, and ophthalmoplegia. Ptosis is defined as an abnormal eyelid “drooping” beyond the normal 1 to 2 mm of the upper limbus of the cornea. Hence, most patients with MG have ophthalmic manifestations. Among all patients with MG, up to half will have exclusively ocular symptoms. In these cases, the condition is referred to as ocular myasthenia. Case Report A 60-year-old man was referred from a neurology clinic for management of intermittent diplopia for greater than 1 year and intermittent bilateral ptosis for the prior year. He reported that he first noticed symptoms of MG at the age of 42, but did not receive the diagnosis until 1 year before his aforementioned neurology examination. He was prescribed spectacles with bilateral ptosis crutches. A diagnosis of severe seronegative MG was subsequently confirmed with neurologic examination and antibody testing. Conclusions Because patients with undiagnosed myasthenia gravis may present initially with ocular signs or symptoms, it is important for the optometrist to be familiar with the condition and the simple “in-office” tests that can be performed to establish a tentative diagnosis and management plan. The optometrist can also participate in the management of ocular manifestations of myasthenia and should be familiar with the use of a ptosis crutch (in addition to prism spectacles or occlusion therapies if indicated) as a nonsurgical intervention for ptosis.
Dynamics and Control of Maneuverable Towed Flight Vehicles

This paper considers the problems of dynamically modeling and automatically controlling the motion of a small maneuverable flight vehicle that is being towed by a much larger one. Mathematical models of the components of the system, including the towing aircraft, tow cable reel mechanism, tow cable, and vehicle aerodynamics, are described. The development of an autopilot for stability augmentation and maneuvering of the towed vehicle is discussed. An overview of the implementation of the models in a digital computer simulation program is provided, and some typical results obtained using the program are presented. A comparison of theoretical and experimental results is also made. ROM the early days of powered flight, there has been an interest in towing objects from aircraft. Objects that have been towed include antennas, banners, gliders, and targets. Because of the interesting, and sometimes troublesome, characteristics of the motions of some towed objects and the cables, or towlines, the dynamics of the cables and the towed objects have been studied by several investigators at various times during the last 60 years.1'10 The problem of describing the motion of a towed cable/ object system is far from trivial. The equations of motion are, in general, coupled, ordinary, and partial differential equations (i.e., hybrid equations). Various approaches have been taken in studying such systems. Glauert1 and Phillips2 did some pioneering work on the stability of the motion of bodies towed from aircraft. Phillips3 also analyzed the stability of the motion of a cable used to tow a nonlifting body. He used a continuum model for the cable and studied the effects of towing speed on the stability of lateral oscillations of the cable and concluded that the oscillations would be damped out if the speed of flight were less than the speed of propagation of vibrational waves along the cable.
Part II. Empowering grassroots evidence-based practice: a curricular model to foster undergraduate student-enabled practice change.

This article presents evidence collected over the past 15 years that attests to the success of curricular innovations conducted to foster socially meaningful contact between nursing students and practicing nurses as a means to promote evidence-based practice (EBP). Action research data collected as these pedagogical strategies have evolved suggest that such student-staff partnerships offer promise not only to encourage commitment to EBP among nursing students but also to surmount most of the barriers that prevent the widespread diffusion of EBP among practicing nurses in clinical settings. Based upon our successful experiences with student-staff interactions, we propose a curricular model—the Student-Enabled Practice Change model–that suffuses the undergraduate nursing school curriculum with opportunities for nursing students to form meaningful partnerships with practicing nurses. The Student-Enabled Practice Change Curricular Model relocates the power to drive practice change to the grassroots level of students and practicing nurses.
Relationship between particle mass and mobility for diesel exhaust particles

We used the aerosol particle mass analyzer (APM) to measure the mass of mobility-classified diesel exhaust particles. This information enabled us to determine the effective density and fractal dimension of diesel particles as a function of engine load. We found that the effective density decreases as particle size increases. TEM images showed that this occurs because particles become more highly agglomerated as size increases. Effective density and fractal dimension increased somewhat as engine load decreased. TEM images suggest that this occurs because these particles contain more condensed fuel and/or lubricating oil. Also, we observed higher effective densities when high-sulfur EPA fuel (∼360 ppm S) was used than for Fischer−Tropsch fuel (∼0 ppm S). In addition, the effective density provides the relationship between mobility and aerodynamic equivalent diameters. The relationship between these diameters enables us to intercompare, in terms of a common measure of size, mass distributions measured with t...
“Standardized intermediates” for oligosaccharide synthesis. Precursors of d-galactopyranose residues having chain extension at position 3, or positions 3 and 2

Abstract A series of 2- O -benzoyl-4,6-di- O -benzyl-α- d -galactopyranosyl halides carrying either a second benzoyl group ( 8a , 12a ) or a selectively removable, temporary protecting group ( 8b–d , 12b ) at position 3 was synthesized from allyl α- d -galactopyranoside ( 1 ). The key intermediate was 1-propenyl 4,6-di- O -benzyl-α- d -galactopyranoside (5), prepared from 1 via the 4,6- O -benzylidene-2,3-di- O -crotyl derivative 2 . The successive incorporation of the 2- O -benzoyl group, by selective acylation at low temperature, and of various 3-substituents gave fully substituted 1-propenyl α- d -galactopyranosides 6a–d . These were converted into the glycosyl halides by published methods. An improved preparation of allyl 2,6-di- O -benzyl-( 15 ) and 2,4,6-tri- O -benzyl-( 19 ) α- d -galactopyranoside was achieved. The direct acetonation of 1 to the 3,4- O -isopropylidene derivative 13 , followed by benzylation and mild acid hydrolysis, gave 15 in 56% yield. The transient protection of O-3 in 15 was accomplished by the alkylation of the dibutylstannylene derivative 16 with (2-methoxyethoxy)methyl chloride. Successive benzylation and mild acid hydrolysis of the product 17 efficiently furnished 19 .
Intrinsic irreversibility in semiconductor light emission

The study of the light emission in semiconductors using energy and entropy balance equations reveals that there is an intrinsic entropy generation built into the emission process. Such an irreversible property provides insight into the conversion of electrical energy into light. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
NORTH CAROLINA MARINE ALGAE. IX. ONSLOWIA ENDOPHYTICA GEN. ET SP. NOV. (PHAEOPHYTA, SPHACELARIALES) AND NOTES ON OTHER NEW RECORDS FOR NORTH CAROLINA1

Four benthic algae are reported here for the first time in the North Carolina flora. The new brown algal genus and species, Onslowia endophytica Searles, is described as an endophyte of Halymenia floridana from the North Carolina continental shelf. New records of Boodleopsis pusilla and Naccaria corymbosa from North Carolina constitute range extensions of these tropical species on the American coast north from Florida. Blastophysa rhizopus, an endophyte and epiphyte known from the North Atlantic coast of Europe and America as well as the Caribbean is reported from North Carolina for the first time and in a new host, Predaea feldmannii.
Implications for the evolution of eukaryotic amino-terminal acetyltransferase (NAT) enzymes from the structure of an archaeal ortholog

Amino-terminal acetylation is a ubiquitous modification in eukaryotes that is involved in a growing number of biological processes. There are six known eukaryotic amino-terminal acetyltransferases (NATs), which are differentiated from one another on the basis of substrate specificity. To date, two eukaryotic NATs, NatA and NatE, have been structurally characterized, of which NatA will acetylate the α-amino group of a number of nonmethionine amino-terminal residue substrates such as serine; NatE requires a substrate amino-terminal methionine residue for activity. Interestingly, these two NATs use different catalytic strategies to accomplish substrate-specific acetylation. In archaea, where this modification is less prevalent, only one NAT enzyme has been identified. Surprisingly, this enzyme is able to acetylate NatA and NatE substrates and is believed to represent an ancestral NAT variant from which the eukaryotic NAT machinery evolved. To gain insight into the evolution of NAT enzymes, we determined the X-ray crystal structure of an archaeal NAT from Sulfolobus solfataricus (ssNAT). Through the use of mutagenesis and kinetic analysis, we show that the active site of ssNAT represents a hybrid of the NatA and NatE active sites, and we highlight features of this protein that allow it to facilitate catalysis of distinct substrates through different catalytic strategies, which is a unique characteristic of this enzyme. Taken together, the structural and biochemical data presented here have implications for the evolution of eukaryotic NAT enzymes and the substrate specificities therein.
ERADICATION OF THE ORIENTAL FRUIT FLY FROM THE MARIANA ISLANDS BY THE METHODS OF MALE ANNIHILATION AND STERILE INSECT RELEASE.

Sterile oriental fruit flies, Dacus dorsalis Hendel, emerging on Guam from 36 million irradiated pupae placed at the loci of infestations established with traps baited with methyl eugenol eradicated the abnonnally small population present after host crops were destroyed by typhoons Karen in 1962 and Olive in 1963. The several reintroductions that occurred in 1964 and 1965 before effective quarantines were established were eradicated by the same method before September 1965. Similar releases on Saipan and Tinian were not successful; too many flies died before reaching sexual maturity, perhaps because sufficient natural food was lacking near the emergence sites (honeydew-producing insects were suppressed by the typhoons) and because of damage by overheating during movement from Guam to field cages on Saipan. Eradication was finally achieved on these islands in 1965 by distributing fiberboard squares impregnated with methyl eugenol and naled every 2-week period for 41/2 months (method of male annihilation). The Mariana Islands, which have been infested with the oriental fruit fly for at least 35 years, have now been free of the species for more than 4 years.
Graphitic Structures by Design

It is shown that self-supporting graphitic structures of specific shape can be grown in a variety of forms, from nanoscale to macroscale, on metal templates, in a fuel-rich mixture of ethylene and oxygen at temperatures between 750 and 900 K. The evidence presented suggests graphite can be grown in any shape created from catalytic metals (e.g., Ni) under the proper conditions of temperature and gas composition. Structures produced include macroscale bodies, centimeters in dimension, composed of micrometer-scale graphite elements such as graphite “foam” and regular graphite “lattices”. Nanoscale hollow graphite spheres were also produced. The production rate in the apparatus employed was roughly shown to be 1 layer/s and was steady with time over several hours. The process of producing self-supporting bodies generally produces hollow graphite structures, as the underlying metal template must be removed by acid following the completion of graphite growth. The process is believed to be possible only in an en...
Recurrent Motion on Precambrian-Age Basement Faults, Palo Duro Basin, Texas Panhandle: ABSTRACT

The distribution of Late Precambrian(?) through Quaternary strata in the Palo Duro basin and surrounding uplifts documents recurrent motion on Precambrian-age basement faults. Basement blocks have been uplifted with little tilting or folding of overlying strata along a system of northwest-southeast oriented faults, part of a regional trend extending from central Colorado to southwestern Oklahoma. The orientation of basement terranes in Colorado and that of a 50-mi (80-km) long mylonite zone in east-central New Mexico suggest a Precambrian age for the faults. An Arkosic sandstone overlies basement and underlies a Cambrian(?) quartzose sandstone in a few Palo Duro basin wells. It may represent debris shed from active fault blocks during the opening of the southern Oklahoma aulocogen in the Late Precambrian or Early Cambrian. Ordovician carbonates thin or are missing beneath Mississippian carbonates on some fault blocks, indicating a post-Ordovician-pre-Mississippian period of faulting. The greatest amount of deformation occurred during the Pennsylvanian. Thickness, distribution, and facies of sediments were controlled by the location of active faults. Lower Pennsylvanian strata thin by up to 50% across some structures. Fault blocks provided sources of arkosic debris and loci for carbonate buildups throughout the Pennsylvanian and Early Permian. Around the periphery of the basin, Late Pennsylvanian or Early Permian faulting caused a wedging out of older units beneath the Wolfcamp. Permian, Triassic, and Neogene units, along with present topography, all have been subtly affected by basement structures. The entire section thins over basement highs. Middle and Upper Permian evaporites are thicker in structural lows. The overlying Dockum Group (Triassic) and Ogallala Formation (Neogene), both nonmarine clastic units, become finer grained over basement highs. Present topographic highs coincide with some basement highs. Also, in some places remarkably straight stream segments parallel basement faults. Low-level seismic activity, primarily north and west of the Palo Duro basin, suggests continuing motion on at least some of the faults. End_of_Article - Last_Page 433------------
Discretionary Disclosure: A Note

This article extends the models of discretionary disclosure. The level of disclosure will be affected by the costs of such disclosure. Verrecchia (1983) shows that when the cost of disclosure is fixed then the threshold level of disclosure is positively related to that cost. Verrecchia (1990a) shows that in the presence of fixed disclosure costs the threshold level of disclosure is negatively related to the quality of information (precision) to be disclosed. The intuition for the result is that as information is more precise, withholding it is more detrimental for the firm and hence the threshold for disclosure is lowered. The model here expands the cost of disclosure to be a function of information quality. When this is the case, the Verrecchia (1990a) unambiguous result does not hold. The presence of information quality in the cost function creates a countervailing force such that more precise information does not necessarily imply more disclosure. This creates the intuitive result that precise information of a proprietary nature might be withheld from the market.
Optical (NIR), magnetic, and conductivity properties of polyacene semiquinones and dianions

Abstract The properties of electrochemically prepared anion-radical and dianion salts of pentacenediquinone(pentacene 5,7,12,14 tetrone) (1) are described. In solution the IR, EPR and unusual (intense, sharp, low energy bands) NIR spectra of 1− Bu4N+ and 1−Li+ are reported and compared to model anion-radicals. SQUID measurements on powders show that 1− Bu4N+ is paramagentic, while 1− Li+ and 1= 2Li+ are diamagnetic. Pressed pellet conductivities are 1−Bu4N+ 1 = 2 Li + = 10 −4 Ω −1 cm −1 .
Solution and solid-state models of peptide CH...O hydrogen bonds.

Fumaramide derivatives were analyzed in solution by (1)H NMR spectroscopy and in the solid state by X-ray crystallography in order to characterize the formation of CH...O interactions under each condition and to thereby serve as models for these interactions in peptide and protein structure. Solutions of fumaramides at 10 mM in CDCl(3) were titrated with DMSO-d(6), resulting in chemical shifts that moved downfield for the CH groups thought to participate in CH...O=S(CD(3))(2) hydrogen bonds concurrent with NH...O=S(CD(3))(2) hydrogen bonding. In this model, nonparticipating CH groups under the same conditions showed no significant change in chemical shifts between 0.0 and 1.0 M DMSO-d(6) and then moved upfield at higher DMSO-d(6) concentrations. At concentrations above 1.0 M DMSO-d(6), the directed CH...O=S(CD(3))(2) hydrogen bonds provide protection from random DMSO-d(6) contact and prevent the chemical shifts for participating CH groups from moving upfield beyond the original value observed in CDCl(3). X-ray crystal structures identified CH...O=C hydrogen bonds alongside intermolecular NH...O=C hydrogen bonding, a result that supports the solution (1)H NMR spectroscopy results. The solution and solid-state data therefore both provide evidence for the presence of CH...O hydrogen bonds formed concurrent with NH...O hydrogen bonding in these structures. The CH...O=C hydrogen bonds in the X-ray crystal structures are similar to those described for antiparallel beta-sheet structure observed in protein X-ray crystal structures.
The functional morphology of xenarthrous vertebrae in the armadillo Dasypus novemcinctus (Mammalia, Xenarthra).

In order to assess the mechanical properties of xenarthrous vertebrae, and to evaluate the role of xenarthrae as fossorial adaptations, in vitro bending tests were performed on posterior thoracic and lumbar vertebral segments excised from specimens of the armadillo Dasypus novemcinctus and the opossum Didelphis virginiana, the latter being used to represent the primitive mammalian condition. The columns of the two species were subjected to dorsal, ventral, and lateral bending, as well as torsion, in order to determine their stiffness in each of these directions. During these tests, bone strains in the centra of selected vertebrae were determined using rosette strain gages. Overall stiffness of the armadillo backbone at physiologically relevant displacement levels was significantly higher than that of the opossum for both dorsal and lateral bending. The two species also exhibited significant differences in angular displacement of individual vertebrae and in vertebral strain magnitudes and orientations in these two directions. No significant differences were observed when the columns of the two species were subjected to torsion or to ventral bending. Our results suggest that some, but not all, of the mechanical differences between the two species are due to the presence of xenarthrae. For example, removal of the xenarthrae from selected vertebrae (L2—L4) changes strain orientation and shear, but not strain magnitudes. Comparisons with functional data from other digging mammals indicate that the modified mechanical properties of the Dasypus column are consistent with an interpretation of xenarthra as digging adaptations and lend support to the idea that the order Xenarthra represents an early offshoot of placental mammals specialized for fossoriality. © 1992 Wiley-Liss, Inc.
Signal Jamming in New Credit Markets

This paper develops a simple two-period model in which a lender's credit operations in a new market end up externalizing information on borrowers' repayment capabilities. This information improves the competitive position of outside lenders by allowing them to enter the credit market with a more accurate description of potential clients. Equilibrium strategies are then identified where an inside lender chooses to offer a costly first-period contract with the explicit objective of distorting the quality of the external information flow in the second period.
Probing polyamide membrane surface charge, zeta potential, wettability, and hydrophilicity with contact angle measurements

Abstract Herein, we present the findings of a study employing contact angle measurements to systematically probe the impacts of solution chemistry (pH, ionic strength, ion valence, etc.) on surface charge, zeta potential, wettability, and hydrophilicity of a commercial polyamide RO membrane. Surface charge density, ionization fraction, and apparent dissociation constants were determined from contact angle titrations and converted to surface (zeta) potentials via the Grahame equation. Contact angle derived zeta potentials qualitatively agreed with zeta potentials independently determined from streaming potential measurements across a range of ionic strengths and pH values, although quantitative differences were significant. Contact angles of polar and apolar non-aqueous liquids were combined with aqueous contact angle titrations to quantify the influence of electrolyte pH, ionic strength, and ionic composition on surface acid–base functionality, wettability, and hydrophilicity. The polyamide membrane used in this study became more electron donor functionalized, more wetting, and less hydrophobic with increasing pH, salinity, and divalent cation content in the electrolyte. These results demonstrate, for the first time, a unified approach to characterize interfacial charge, electro-kinetic, and acid–base properties of polyamide composite RO membranes using a single analytical instrument.
Characterization of Fine-Grained Superplastic Aluminum Alloys

This paper summarizes the results of some recent research on a thermomechanical method of refining the grain size in precipitation hardenable aluminum alloys and illustrates the infuence of grain refinement on several material properties. Grain refinement is achieved by deliberately introducing a large number of nucleation sites for recrystallization and by controlling grain growth after recrystallization. Recrystallization to a relatively small and equiaxed grain size has been achieved in a number of commercial aluminum alloys using these concepts. The influence of the fine recrystallized grain size on such properties as superplastic deformation, room temperature tensile properties, fatigue life, and exfoliation corrosion resistance is discussed. The results show that refinement to a grain size of 8–14 µm is sufficient to develop extensive superplasticity and to yield a small increase in tensile properties in alloys such as 7075 and 7475.
A density functional study of structure and heat of formation for Br2O4 and Br2O5

Abstract The equilibrium structure, and heat of formation for both Br2O4 and Br2O5 molecules have been investigated using density functional theory. Four isomers for the Br2O4 and five isomers for the Br2O5 molecules are located. At B3LYP/6-311+G(3df) level of theory the heat of formation of the Br2O4 and Br2O5 molecules has been estimated to be in the range 68.7– 76.0 kcal mol −1 and 80.8– 107.5 kcal mol −1 , respectively. Analysis of the heat of formation, the structure of the isomers, and bromine–oxygen chemistry suggests that the gaseous Br2O4 and Br2O5 molecules may have a structure of BrOOBrO2 and O2BrOBrO2/BrOOBrO3/OBrOBrO3, respectively.
Scales of Reading

AbstractWe read according to different scales: fast or slow, selective or thorough, deeply or skimming along. What is at stake in scalar variations like these? Quite a lot, this essay argues. The contrast between close reading and distant reading, as formulated by Franco Moretti, raises provocative challenges for the discipline of literary study. Moretti’s claim that “knowing is not reading” exemplifies the current devaluation — and undertheorization — of the kind of knowledge that close reading produces. “Distant reading” converges with recent critiques of historicism, experiments in machinic reading, and narratives of the “turn away from the linguistic turn” to foreground the epistemological limits of interpreting individual texts. In light of these challenges, I advocate the reexamination of precisely what we learn through close reading. This project, of articulating anew the terms of literary-historical understanding, may be aided by resources of the hermeneutic tradition — although the possibility se...
Intracellular ion concentrations in the isolated frog skin epithelium: evidence for different types of mitochondria-rich cells.

Intracellular ion concentrations were determined in split skins of Rana pipiens using the technique of electron microprobe analysis. Under control conditions, principal cells and mitochondria-rich cells (MR cells) had a similar intracellular ion composition, only the Cl concentration in MR cells was significantly lower. Inhibition of transepithelial Na transport by low concentrations of ouabain (2 × 10−6 m, innerbath) resulted in a Na concentration increase of principal cells from 10.9 to 54.3 mmol/kg wet wt. The increase was completely abolished by simultaneous application of amiloride (10−4 m, outer bath). Amiloride alone resulted in a significant decrease of the Na concentration to 6.1 mmol/kg. w. w. Among MR cells, two different groups of cells could be distinguished; cells that showed a Na increase after ouabain which was even larger than that in principal cells and cells that did not respond to ouabain. In about half of all ouabain-sensitive MR cells the Na increase could be prevented by amiloride. According to these results, a subpopulation of MR cells displays the transport characteristics expected for a transepithelial Na transport compartment, an apical amiloride-sensitive Na influx and abasal ouabain-inhibitable Na efflux. Given the small number of cells, however, it is unlikely that this subtype of MR cells contributes significantly to the overall rate of transepithelial Na transport.
Expansions in nearly linear stochastic dynamical problems

Abstract A class of stochastic differential equations is considered which arises by adding a nonlinear term with a small parameter δ in the drift coefficient of a linear stochastic system. First, for a fixed time an expansion in powers of δ of the expectations of functions is established. Second, under the assumptions guaranteeing the existence of a unique ergodic measure, the corresponding expansion of the expectations of functions with respect to the invariant measure in powers of δ , δ 2 ,… is also established.
Lessons for Dynamic Touch From a Case of Stroke-Induced Motor Impairment

LW, an individual with a stroke-related motor impairment, was asked to perceive the lengths of rods of different mass distributions by dynamic touch. His impairment dictated that wielding was primarily about the shoulder rather than the wrist. Although perceived rod lengths were in the range of actual rod lengths, scaling to the objects' mass moments was atypical for both the affected and unaffected limbs. A group of healthy young adults asked to mimic his wielding style yielded the same atypical scaling. The typical scaling was restored when LW's wielding was fixed about a mechanical axis. Discussion considered what frame of reference is suitable for revealing an object's mass moments relevant to a given task. In particular, it appears that individuals can exploit alternative forms of interaction with environmental objects that leave invariant the parameters specifying to-be-perceived properties. Perception by dynamic touch is not a function of particular neuromuscular patterns but of information made av...
Radioimmunotherapy for patients with relapsed B-cell non-Hodgkin lymphoma.

Clinical trials of an yttrium-90 (90Y)-conjugated monoclonal antibody to CD20 in patients with relapsed B cell non-Hodgkin lymphoma (NHL) are reviewed. Ibritumomab is the murine parent anti-CD20 antibody engineered to make the human chimeric antibody rituximab. Tiuxetan is an MX-DTPA linker chelator attached to ibritumomab to form ibritumomab tiuxetan (Zevalin). Ibritumomab tiuxetan can react with indium-111 (111In) or 90Y to form 111In-ibritumomab tiuxetan, which is used for dosimetry, or 90Y-ibritumomab tiuxetan, which is used for therapy of B cell NHL. In this report, the results of five separate clinical trials of ibritumomab tiuxetan are reviewed. Two phase I trials of 90Y-ibritumomab tiuxetan were performed, one using cold ibritumomab prior to 90Y-ibritumomab tiuxetan, and one using rituximab prior to 90Y-ibritumomab tiuxetan. The optimal schedule was found to be rituximab on days 1 and 8, and 90Y-ibritumomab tiuxetan 0.4 mCi/kg i.v. on day 8; no stem cells or prophylactic growth factors were used. A dose of 0.3 mCi/kg was recommended for patients with a baseline platelet count of 100,000–149,000×106/l. The only significant toxicity was reversible myelosuppression. With this schedule, the overall response rate (ORR) was 67% of all patients and 82% of those with low-grade NHL. The phase I/II trials were followed by a phase III trial that randomized 143 eligible patients to either rituximab or 90Y-ibritumomab tiuxetan radioimmunoconjugate to demonstrate that the combination of the 90Y radioisotope to the murine anti-CD20 antibody provided additional efficacy over the unconjugated ("cold") rituximab alone. A planned interim analysis of the first 90 patients demonstrated an ORR of 80% with 90Y-ibritumomab tiuxetan vs 44% for rituximab (P<0.05). To provide additional evidence of the benefit of 90Y radioimmunotherapy over rituximab immunotherapy, patients who were nonresponsive or refractory to rituximab were enrolled in an additional trial and treated with 90Y-ibritumomab tiuxetan 0.4 mCi/kg. An ORR of 46% was achieved in these rituximab-refractory patients. These results provide further evidence of the added value of 90Y. Therefore 90Y-ibritumomab tiuxetan radioimmunotherapy is a useful new treatment modality for patients with B cell NHL. Future trials are needed to define the optimal time in the disease course when this modality should be used.
Experimental investigation of low-pressure refrigerant mixtures for micro cryogenic coolers

Abstract Micro Cryogenic Coolers (MCCs) can achieve very small sizes and high efficiencies when operating with a refrigerant mixture, but micro-scale compressors have a limited pressure output. Four refrigerant mixtures were designed to operate between 0.4 MPa and 0.1 MPa, and tested in a MCC system both with and without pre-cooling. For comparison, two pure refrigerants were tested as well. Without pre-cooling, each mixture exhibited considerably lower cooling power than the design value. With pre-cooling, the mixtures exhibited unsteady cooling temperatures accompanied by flow pulsations after a period of time. The low cooling power, unsteady temperatures, and time required for the pulsations to occur are analyzed in terms of composition change due to liquid hold-up in the annular and intermittent flow regimes.
Latching micromagnetic optical switch

In this paper, we report a new type of latching micromagnetic optical switch. The key component of this optical switch is a cantilever made of soft magnetic material with a reflective surface serving as a mirror. The cantilever has two stable positions, therefore two stable states for the device, with presence of an external magnetic field. Input optical signal to the device is switched selectively to one of the two output ports when the device transitions between the two states upon short electromagnetic actuations. The optical switch is bistable because the cantilever has a tendency to align with the external magnetic field, and the torque to align the cantilever can be bidirectional depending on the angle between the cantilever and the magnetic field. Switching between the two stable states is accomplished by momentarily changing the direction and/or the magnitude of the cantilever's magnetization by passing a short current pulse through a planar coil underneath the cantilever. In either of its stable state, the cantilever is held in position by the combined influence of the static external magnetic field and mechanical force, such as from a physical stopper or a mechanical torque produced by the torsion flexures supporting the cantilever. Stable vertical position for the cantilever is obtained by using a tilted external magnetic field. When the cantilever mirror is at this UP state, light is reflected to the desired output port. Large angle deflection and bistable latching operations have been demonstrated. The measured mechanical switching speed between the two states of the prototype is 3.2 ms. Optical insertion loss is -4 dB, and the energy consumption is 44 mJ for each switching event.
The karst contagion model: Synopsis and environmental implications

The contagion model of karst terrane evolution focuses on the environmental implications for a large karst depression population on the Pennyroyal Plain (southern Kentucky) and the adjacent Western Highland Rim (Tennessee) immediately south of the Mammoth Cave Plateau. In karst terranes where the contagion model applies, there is a well-defined infrastructure comprised of hydrologic, structural geologic and geomorphic interacting elements that result in clustered depressions underlain by a radial conduit system. Clusters tend to be randomly distributed and typically contain a parent depression surrounded by numerous daughters.