cssi/SciSciGPT-SciSciNet huggingface dataset:
Expression and activation of the epidermal growth factor receptor in differentiating cells of the developing and post-hatching chicken lens

The epidermal growth factor receptor is hypothesized to play an important role in the post-natal growth and differentiation of the ocular lens. Immunohistochemistry and western blotting were utilized to examine the distribution and activation of the epidermal growth factor receptor in embryonic and post-hatching chicken lenses. Although present at constant levels within epithelial cells throughout embryonic development, the receptor becomes increasingly activated on a highly conserved tyrosine residue necessary for intracellular signal transduction as hatching approaches. After hatching, activated receptors are found in epithelial cells committed to fiber cell formation and in fiber cells undergoing initial stages of terminal differentiation. Activated receptors could not be identified in central epithelial cells or nuclear fiber cells. This pattern persists until at least one year post-hatching. These data indicate that the epidermal growth factor receptor is positioned to influence not only post-natal patterns of lenticular gene expression but also the greatest amount of lens growth and development.
Redesigning air cathodes for metal–air batteries using MnOx-functionalized carbon nanofoam architectures☆

a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
Quantum resonance structure in the three-dimensional F + H2 reaction

Abstract Evidence for a quantum resonance in the three-dimensional F + H 2 ( v = 0, i = 0) → FH( v = 2, all i ) + H reaction is presented. Relative to the collinear reaction, this resonance is much broader and is shifted by about 0.1 eV to higher energies. This resonance has not been predicted in previous quasiclassical trajectory computations, or in approximate quantum calculations.
A benchmark for comparative dynamics and determinacy in overlapping-generations economies

Abstract Do self-fulfilling prophecies inherently produce indeterminate price paths? After attention is restricted to nearly stationary price paths and economies, the local uniqueness of equilibrium paths is established for almost all eternal (without beginning or end) overlapping-generations economies with perfect foresight. Those results sharply contrast with leading examples of indeterminacy. Such divergent results are possible since each leading example actually violates perfect foresight: all but a finite number of their equilibrium paths embody either unanticipated revisions of expectations or extrinsic uncertainty (sunspots).
Annulations in bridged systems. An approach to the synthesis of shikodonin

Abstract A broadly-useful strategy for the introduction of a bridgehead substituent and a substituent on an adjacent carbon is described. The addition of TMSX to a bridgehead enone generates an enol silyl ether regiospecifically. Reaction of the enol silyl ether with electrophiles results in a vicinal dialkylation.
Personality disorder traits: prevalence and effects on health status in primary care patients.

Objective:Previous work in an academic setting has found that scoring in the higher ranges for selected personality disorders on an objective assessment tool was associated with increases in psychi...
A Comparison between the Height of Cumulus Clouds and the Height of Radar Echoes Received from Them1

Abstract A comparison is made between the angular elevation of the visible top of a cloud tower and the top of the radar echo associated with it. Employing a 10-cm WSR-57 radar, we find angular differences between 0 and +1° with the radar elevation higher. Our sample is 32 clouds with cops from 16,000 to 53,000 ft at ranges between 10 and 35 n mi in the vicinity of Miami, Fla. From the known sensitivity of the radar we have deduced that in the upper 500—1500 ft of these clouds the average equivalent reflectivity factor Z has values between a few tenths and a few mm6m−2. Because of these low values when the conventional beam-width correction is made, the height of the visible top exceeds that of the radar top by 200–3000 ft.
The molecular structure of gaseous tetrachloro-p-benzoquinone and tetrachloro-o-benzoquinone by electron diffraction

Abstract The structures of tetrachloro- p -benzoquinone and tetrachloro- o -benzoquinone ( p - and o -chloranil) have been investigated by gas electron diffraction. The ring distances are slightly larger and the carbonyl bonds slightly smaller than in the corresponding unsubstituted quinones. The molecules are planar to within experimental error, but small deviations from planarity such as those found for the para compound in the crystal are completely compatible with the data. Values for the geometrical parameters ( r a distances and bond angles) and for some of the more important amplitudes ( l ) with parenthesized uncertainties of 2σ including estimated systematic error and correlation effects are as follows. Tetrachloro- p -benzoquinone: D 2h symmetry (assumed); r (CO) = 1.216 A(4), r (CC) = 1.353 A(6), r (C-C) = 1.492 A(3), r (C-Cl) = 1.701 A(3), ∠C-C-C = 117.1° (7), ∠CC-C1 = 122.7° (2), l (CO)= 0.037 A(5), l (CC) = l (C-C) - 0.008 A(assumed) = 0.049 A(7), and l (C-Cl) = 0.054 A(3). Tetrachloro- o -benzoquinone: C 2v symmetry (assumed); r (CO) = 1.205 A(5), r (CC) = 1.354 A(9), r (C cl -C cl ) = 1.478 A(28), r (Co-C cl ) = 1.483 A(24), r (C o -C o ) = 1.526 A(2), r (C-Cl)= 1.705 A(3), o -CO = 121.0° (22), ∠C-C-C = 117.2° (9), ∠C co , ClC-Cl = 118.9° (22), ∠C ccl , ClC-Cl = 122.2°(12), l (CO) = 0.039 A(5), and l (C cl -C cl ) = l (C o -C cl ) = l ( Co-Co) = l (CC) + 0.060 A(equalities assumed) = 0.055 A(9). Vibrational'shortenings (shrinkages) of a few of the long non-bond distances have also been measured.
The Kennedy Krieger Independence Scales-Spina Bifida Version: a measure of executive components of self-management.

Kennedy Krieger Institute, Baltimore, Maryland and Johns Hopkins University Purpose/Objective: Successful implementation of functional self-care skills depends upon adequate executive functioning; however, many scales assessing adaptive skills do not address the inherent executive burden of these tasks. This omission is especially relevant for individuals with spina bifida, for whom medical self-care tasks impose a significant burden requiring initiation and prospective memory. The Kennedy Krieger Independence Scales-Spina Bifida Version (KKIS-SB) is a caregiver-reported measure designed to address this gap; it assesses skills for managing both typical and spina bifida-related daily self-care demands, with a focus on the timely and independent initiation of adaptive skills. Research Method/Design: Parents of 100 youth and young adults with spina bifida completed the KKIS-SB. Exploratory factor analysis and Pearson's correlations were used to assess the factor structure, reliability, and construct validity of the KKIS-SB. Results: The scale demonstrates excellent internal consistency (Cronbach's alpha .891). Exploratory factor analysis yielded four factors, explaining 65.1% of the total variance. Two primary subscales were created, initiation of routines and prospective memory, which provide meaningful clinical information regarding management of a variety of typical (e.g., get up on time, complete daily hygiene routines on time) and spina bifida-specific self-care tasks (e.g., begin self-catheterization on time, perform self-examination for pressure sores). Conclusions/ Implications: Based upon internal consistency estimates and correlations with measures of similar constructs, initial data suggest good preliminary reliability and validity of the KKIS-SB.
Innate immunity to Toxoplasma gondii infection

Toxoplasma gondii is a protozoan parasite of global importance. In the laboratory setting, T. gondii is frequently used as a model pathogen to study mechanisms of T helper 1 (TH1) cell-mediated immunity to intracellular infections. However, recent discoveries have shown that innate type 1 immune responses that involve interferon-γ (IFNγ)-producing natural killer (NK) cells and neutrophils, rather than IFNγ-producing T cells, predetermine host resistance to T. gondii. This Review summarizes the Toll-like receptor (TLR)-dependent mechanisms that are responsible for parasite recognition and for the induction of IFNγ production by NK cells, as well as the emerging data about the TLR-independent mechanisms that lead to the IFNγ-mediated elimination of T. gondii.
Radiometric performance results of the Lunar Reconnaissance Orbiter's Lyman Alpha Mapping Project (LRO/LAMP) UV imaging spectrograph

We describe the pre-flight radiometric performance and calibration results of the Lunar Reconnaissance Orbiter's Lyman Alpha Mapping Project (LRO/LAMP) flight model. LAMP is a lightweight (6.1 kg), low-power (4.5 W), ultraviolet spectrograph based on the ALICE instruments now in flight aboard the European Space Agency's Rosetta spacecraft and NASA's New Horizons spacecraft. Its primary job will be to identify and localize exposed water frost in permanently shadowed regions (PSRs), and to characterize landforms and albedos in PSRs. Detailed radiometric performance results of the LAMP flight model are presented and discussed.
A Ramsey theoretic problem for finite ordered sets

Before presenting our results on this problem, we pause to introduce some basic notation and terminology and to make some observations concerning the background of this problem. Throughout the paper, we consider only finite ordered sets. If P is an ordered set and X, y E P, we write x 11 y when x and y are incomparable. For a positive integer r, we let r = { 1, 2, . . . , r}. An r-coloring of an ordered set Q is a mapping C$ : Q -+ r of the points of Q to a set of r elements. In this setting, the elements of r are called colors. When @ is an r-coloring of Q and cx E r, a subordered set P of Q such that $(x) = LY for every x E P is called a monochromatic subordered set (of color (u). In this paper, we are primarily interested in the case r = 2. Accordingly, we write Q* P when every 2-coloring of Q produces a monochromatic copy of P, i.e., for every 2-coloring @ : Q + 2, there exists an LY E 2 and a monochromatic subordered set P’ of color (Y so that P’ is isomorphic to P. To indicate that the statement that Q+ P is false, we will write Q-,4= P.
STS Requires Changes in Teaching.

The major advantage of STS is the kind of teaching it allows and demands. Twelve middle school teachers who were enthused with STS teaching selected two sections for a research study. One section was the experimental STS section; the other followed the course syllabus and textbook closely. The major findings indicate the advantages for STS as a teaching approach.Students at the STS approach learned as many science concepts as students who were taught such concepts directly. But the students in the STS sections were superior in all other aspects, including understanding and use of 14 process skills, use of creative thinking skills, development of more positive attitudes, better ability to apply and connect ideas and skills to other situations, and developing a better understanding of the nature and history of science.
Aggregation kinetics of interrupted polyglutamine peptides.

Abnormally expanded polyglutamine domains are associated with at least nine neurodegenerative diseases, including Huntington's disease. Expansion of the glutamine region facilitates aggregation of the impacted protein, and aggregation has been linked to neurotoxicity. Studies of synthetic peptides have contributed substantially to our understanding of the mechanism of aggregation because the underlying biophysics of polyglutamine-mediated association can be probed independent of their context within a larger protein. In this report, interrupting residues were inserted into polyglutamine peptides (Q20), and the impact on conformational and aggregation properties was examined. A peptide with two alanine residues formed laterally aligned fibrillar aggregates that were similar to the uninterrupted Q20 peptide. Insertion of two proline residues resulted in soluble, nonfibrillar aggregates, which did not mature into insoluble aggregates. In contrast, insertion of a β-turn template DPG rapidly accelerated aggregation and resulted in a fibrillar aggregate morphology with little lateral alignment between fibrils. These results are interpreted to indicate that (a) long-range nonspecific interactions lead to the formation of soluble oligomers, while maturation of oligomers into fibrils requires conformational conversion and (b) that soluble oligomers dynamically interact with each other, while insoluble aggregates are relatively inert. Kinetic analysis revealed that the increase in aggregation caused by the DPG insert is inconsistent with the nucleation–elongation mechanism of aggregation featuring a monomeric β-sheet nucleus. Rather, the data support a mechanism of polyglutamine aggregation by which monomers associate into soluble oligomers, which then undergo slow structural rearrangement to form sedimentable aggregates.
Spontaneous chromosome rearrangements in the protozoan Giardia lamblia: estimation of mutation rates.

Abstract Subcloned lines of the WB strain of Giardia lamblia contain polymorphic ribosomal RNA (rRNA) encoding chromosomes (Le Blancq et al., Nucl. Acids Res. 1991, 19, 4405-4412). We show that in a continuously propagated culture of G.lamblia trophozoites the proportion of trophozoites with rearranged rRNA encoding chromosomes gradually increases, consistent with the high mutation rate of about 1% per cell per division cycle. This conclusion is based on the finding in one experiment that after about 8 division cycles 20% of the population consisted of independent mutants, while after approximately 100 division cycles 87.5% of the population were independent mutants. In a second experiment, approximately 38% and 71.5% of the trophozoites were independent mutants after approximately 9 and approximately 100 division cycles, respectively. The data show that the genome of the WB strain of G.lamblia has a highly recombinogenic phenotype. Extensive karyotype heterogeneity has also been observed among recently isolated G.lamblia strains obtained from a defined geographic area (Korman et al., J. Clin. Invest. 1992, 89, 1725-1733) suggesting that a high mutation rate might also occur in vivo.
Neutral aldoses as source indicators for marine snow

Abstract The chemical characteristics of aggregating material in the marine environment are largely unknown. We investigated neutral aldose (NA) abundance and composition in aggregation of marine snow and other organic matter (OM) size fractions in the field. Four sample sets were fractionated using membrane filtration and ultrafiltration into the following size fractions: particulate material, high-molecular-weight (HMW) material, and low-molecular-weight (LMW) material. We also collected three sample sets of marine-snow aggregates. Each sample set contained small, medium, and large aggregate size fractions and each size fraction consisted of 25–50 aggregates. For 7 marine-snow samples and for each water-sample size fraction, we determined monomeric and polymeric NA concentration, NA yield (amount of NA-C normalized to organic carbon), and composition; total organic carbon (TOC) concentration; transparent exopolymer particles (TEP) concentration, and TEP propensity (TEP concentration after inducing TEP formation in filtered samples). This is the first study to include compound-specific NA determinations on these four marine OM size fractions. The mass balances of organic carbon and NA indicated that there were no serious contamination or loss problems. Concentrations, yields, and NA mol fractions in water samples were similar to results from other studies. Glucose and galactose had the highest relative abundance in all size fractions. The NA yield increased with increasing molecular weight or particle size for all fractions except marine snow. The NA yield increased in the order: LMW TEP concentration or TEP propensity was positively correlated with concentrations of all individual NAs as well as the sum NA concentrations, indicating that TEP contains neutral sugars in addition to the acidic polysaccharides stained in the determination of TEP concentrations. Despite the relatively low NA yield in marine snow, marine snow was enriched in NA when compared with seawater, with enrichment factors of 34–225 (average 125). By combining data from this study with data from other studies, we estimate that There was no clear correlation between marine-snow aggregate size and NA yield, that is, there appears to be no general age difference between small and large marine-snow aggregates. NA composition was similar among different marine-snow size fracions collected during the same day, indicating that aggregation/disaggregation reactions resulted in homogenizing NA composition in marine-snow aggregates of all sizes. The NA composition of marine snow was different from that of other OM size fractions, indicating either that bacterial degradation has modified the composition of marine snow to a larger extent than other OM size fractions or that marine snow is formed through the aggregation of selected subcomponents of OM.
Conspecific brood parasitism as a flexible female reproductive tactic in American coots

Abstract Abstract. Conspecific brood parasitism was a common component of reproduction in a population of American coots, Fulica americana , in central British Columbia, Canada. In a 4-year study, over 40% of nests were parasitized and 13% of all eggs were laid parasitically. Parasitism occurred in several ecological contexts, each involving different constraints and trade-offs. A quarter of the parasitic eggs were attributed to floater females without nests or territories of their own. The annual reproductive success of floaters was 16 times lower than that of territorial, nesting females, indicating that parasitism was a low-paying alternative to non-breeding rather than a specialized, equal-fitness alternative to nesting. Nest loss during laying accounted for few cases of parasitism. Most of the parasitism in the population was attributed to nesting females that laid additional eggs parasitically. One quarter of the nesting females were parasitic, and these females usually laid parasitically prior to laying full-sized clutches in their own nests. Brood reduction through starvation was prevalent in all years and on all wetlands, indicating that post-hatching parental care limits the number of offspring that pairs can raise in their own nests. By laying surplus eggs parasitically, females can bypass the constraints of parental care and increase their total production of offspring. As a flexible reproductive tactic used in several ecological contexts, parasitism permits a more finely tuned life-history strategy for dealing with reproductive and social constraints.
Collaboratory testbed partnerships as a knowledge capture challenge

The difficulty of maintaining effective testbed partnerships, among users of computer-based tools and builders of those tools, has been an obstacle to the success of science collaboratories. Testbed partnerships are as essential for knowledge-tool advancement as that advancement is to the support of effective partnerships, because knowledge tools must be instituted in a context that truly augments (rather than merely tries to replicate) human inference in collaborative contexts. We propose a game framework for engaging content-tool users and context-tool developers in testbed partnerships, and an architecture for modular knowledge-tool integration, as initial steps in the effective advancement of knowledge capture and improvement of testbed partnerships.
Interacting with massive numbers of student solutions

When teaching programming or hardware design, it is pedagogically valuable for students to generate examples of functions, circuits, or system designs. Teachers can be overwhelmed by these types of student submissions when running large residential or recently released massive online courses. The underlying distribution of student solutions submitted in response to a particular assignment may be complex, but the newly available volume of student solutions represents a denser sampling of that distribution. Working with large datasets of students' solutions, I am building systems with user interfaces that allow teachers to explore the variety of their students' correct and incorrect solutions. Forum posts, grading rubrics, and automatic graders can be based on student solution data, and turn massive engineering and computer science classrooms into useful insight and feedback for teachers. In the development process, I hope to describe essential design principles for such systems.
Nicotine Exposure during Adolescence Enhances Behavioral Sensitivity to Nicotine during Adulthood in Wistar Rats

Abstract Rationale Drug use during adolescence is associated with an increased propensity for drug dependency during adulthood. Therefore, the effects of adolescent exposure to nicotine on adult behavioral responsiveness to nicotine are of particular importance. Objectives The objective of the current study was to determine if adolescent nicotine exposure would enhance behavioral sensitivity and development of sensitization to nicotine during adulthood. Materials and methods Male Wistar rats were assigned to one of three groups that received subcutaneous (s.c.) injections of nicotine (0, 0.25, or 0.5 mg/kg) in the home cage for 12 consecutive days during adolescence, PD 31–42. Starting on PD 80, distance traveled, rearing, and stereotypy were recorded in locomotor activity chambers each day for 10 days, following s.c. injections of 0, 0.25, or 0.5 mg/kg nicotine. One week later, a final challenge session took place during which rats were injected with 0.5 mg/kg nicotine. Results Rats exposed to nicotine during adolescence displayed a greater locomotor response to a novel environment than saline-treated rats. Adolescent nicotine treatment also resulted in context-independent sensitization to the acute locomotor activating properties of nicotine, including distance traveled and stereotypy, as measured on the first day of adulthood nicotine exposure. Adolescent nicotine-treated rats displayed increased sensitivity to repeated nicotine exposures during adulthood, compared to adolescent saline-treated rats, as measured by distance traveled, rearing, and stereotypic behaviors. Finally, rats treated with nicotine only during adolescence were more sensitive to a final nicotine challenge during adulthood than rats treated with nicotine only previously during adulthood. Conclusions Overall, the results suggest that adolescent nicotine treatment predisposes adult rats to develop increased behavioral sensitivity to chronic nicotine treatment and to be more sensitive to the initial effects of nicotine.
NONCOMMUTATIVE CORRECTIONS TO THE MIC–KEPLER HAMILTONIAN

Noncommutative corrections to the MIC–Kepler system (i.e. hydrogen atom in the presence of a magnetic monopole) are computed in Cartesian and spherical coordinates. In the framework of perturbation theory we were able to derive noncommutative corrections to the MIC–Kepler spectrum. We also found a nontrivial contribution to the linear Stark effect which did not exist in the standard hydrogen model.
Robust stability under mixed time-varying, time-invariant and parametric uncertainty

Robustness analysis is considered for systems with structured uncertainty involving a combination of linear time-invariant and linear time-varying perturbations, and parametric uncertainty. A necessary and sufficient condition for robust stability in terms of the structured singular value μ is obtained, based on a finite augmentation of the original problem. The augmentation corresponds to considering the system at a fixed number of frequencies. Sufficient conditions based on scaled small-gain are also considered and characterized.
Projection Lenses for a C-Size Light-Valve Display

We studied two types of projectors for a liquid-crystal-display breadboard and designed and used an on-axis f/4 lens.
Counterion-mediated cluster formation by polyphosphoinositides

Abstract Polyphosphoinositides (PPI) and in particular PI(4,5)P2, are among the most highly charged molecules in cell membranes, are important in many cellular signaling pathways, and are frequently targeted by peripheral polybasic proteins for anchoring through electrostatic interactions. Such interactions between PIP2 and proteins containing polybasic stretches depend on the physical state and the lateral distribution of PIP2 within the inner leaflet of the cell's lipid bilayer. The physical and chemical properties of PIP2 such as pH-dependent changes in headgroup ionization and area per molecule as determined by experiments together with molecular simulations that predict headgroup conformations at various ionization states have revealed the electrostatic properties and phase behavior of PIP2-containing membranes. This review focuses on recent experimental and computational developments in defining the physical chemistry of PIP2 and its interactions with counterions. Ca2+-induced changes in PIP2 charge, conformation, and lateral structure within the membrane are documented by numerous experimental and computational studies. A simplified electrostatic model successfully predicts the Ca2+-driven formation of PIP2 clusters but cannot account for the different effects of Ca2+ and Mg2+ on PIP2-containing membranes. A more recent computational study is able to see the difference between Ca2+ and Mg2+ binding to PIP2 in the absence of a membrane and without cluster formation. Spectroscopic studies suggest that divalent cation- and multivalent polyamine-induced changes in the PIP2 lateral distribution in model membrane are also different, and not simply related to the net charge of the counterion. Among these differences is the capacity of Ca2+ but not other polycations to induce nm scale clusters of PIP2 in fluid membranes. Recent super resolution optical studies show that PIP2 forms nanoclusters in the inner leaflet of a plasma membrane with a similar size distribution as those induced by Ca2+ in model membranes. The mechanisms by which PIP2 forms nanoclusters and other structures inside a cell remain to be determined, but the unique electrostatic properties of PIP2 and its interactions with multivalent counterions might have particular physiological relevance.
Variations in anatomy of the middle hepatic vein and their impact on formal right hepatectomy.

Background: We evaluated the incidence of variations of the middle hepatic vein (MHV) branches and their impact on formal right hepatectomy for living-donor liver transplantation.
Is poliomyelitis a genetically-determined disease: I: A genetic model.

Abstract Previous work suggesting genetic susceptibility to paralytic poliomyelitis is reviewed and previous explanations of the high attack rate at Chesterfield Inlet, 1948, are rejected as incompatible with other data. The case-fatality rate in many epidemics is interpreted as showing two different populations of those attacked. A model of genetic susceptibility is proposed in which susceptibility to paralytic poliomyelitis is inherited as a single gene (p + ) and that homozygotes (p + p + ) become susceptible soon after birth whereas heterozygotes (p + p − ) do not become susceptible till a later age. The over-riding role of immunity is discussed. The Hardy-Weinberg formula is used to analyse the New York Epidemic 1916 and the Chesterfield Inlet Epidemic among Eskimos in 1948: the case-rates of paralytic poliomyelitis are shown to be compatible with the model and the populations to be genetically similar. Clinical aspects of the disease are reassessed and unified by the model. The role of other genes affecting susceptibility is discussed.
Optically Controlled Active Inductor

An optically controlled MMIC compatible active inductor is demonstrated. The device is realized by a MESFET based circuit configuration which exhibits a shunt inductive characteristic which may be tuned by direct illumination of one of the circuit's MESFETs. The optically tuned active inductor may then be incorporated into a variety of microwave circuits whose performance may be controlled via direct optical illumination of the active inductor.
Study of Li1+x(Mn4/9Co1/9Ni4/9)1-xO2 Cathode Materials for Vehicle Battery Applications

Li{sub 1+x}(Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9}){sub 1-x}O{sub 2} with two lithium content (x = 0 and 0.05) has been synthesized using coprecipitated (Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9})(OH){sub 2} and their electrochemical properties have been investigated. Compared with the x = 0 material, the lithium-rich material (x = 0.05) exhibited superior electrochemical properties. When cycled between 2.5 and 4.4 V, the Li/Li{sub 1.05}(Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9}){sub 0.95}O{sub 2} cells showed high first-cycle coulombic efficiency (93%), reversible discharge capacity of 187 mAh/g at C/12 with 99% capacity retention after 40 cycles, and excellent rate performance (86% of C/12 rate at 5 C discharge current). The Li{sub 1.05}(Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9}){sub 0.95}O{sub 2} electrode also showed a full-cell pulse power characteristics (5 C discharge pulse) comparable to Li{sub 1.05}(Mn{sub 1/3}Co{sub 1/3}Ni{sub 1/3}){sub 0.95}O{sub 2} electrode and better thermal stability at charged state (4.4 V) than charged LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2} (4.2 V). Using a battery design and cost model developed in-house, calculations found battery packs with Li{sub 1.05}(Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9}){sub 0.95}O{sub 2} as the positive electrode to be of lower cost and higher energy density than those with LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2} and Li{sub 1.05}(Mn{sub 1/3}Co{sub 1/3}Ni{sub 1/3}){sub 0.95}O{sub 2} electrodes. Themore » experimental and modeling results obtained in this work suggest Li{sub 1.05}(Mn{sub 4/9}Co{sub 1/9}Ni{sub 4/9}){sub 0.95}O{sub 2} to be a promising cathode material for vehicle battery applications.« less
Oxide layers on III V compound semiconductors

Abstract Results of an investigation of the thermal and anodic oxidation of the III–V compound semiconductors are presented. First the growth models for the thermal oxidation of metals and alloys are reviewed. From these, a model for the growth of thermal oxides on the III–V compounds is proposed. It is shown that the diffusion rates of the elements, the mutual solubilities of the mixed oxides and the thermodynamic stabilities of the oxides are important factors in the oxide growth. Auger compositional profiles of the thermal oxides show that some oxides partition into two layers while others are nearly uniform. The insulating properties of these oxides are shown to be related to the chemical composition. The Auger profiles of the anodic oxides are contrasted with those of the thermal oxides.
Estimating a Multivariate Proportional Hazards Model for Clustered Data Using the EM Algorithm, with an Application to Child Survival in Guatemala

Abstract This article discusses a random-effects model for the analysis of clustered survival times, such as those reflecting the mortality experience of children in the same family. We describe parametric and nonparametric approaches to the specification of the random effect and show how the model may be fitted using an accelerated EM algorithm. We then fit two specifications of the model to child survival data from Guatemala. These data had been analyzed before using standard hazard models that ignore cluster effects.
The δ‐function counterion condensate around a line charge derived from the Fuoss, Katchalsky, and Lifson polyelectrolyte theory

It has recently been proven that the counterion condensate around an isolated line charge in an electrolyte, as characterized by nonlinear Poisson-Boltzmann theory, is an encapsulating δ-function. Here the identical result is shown to hold in the framework of the polyelectrolyte theory of Fuoss, Katchalsky, and Lifson. The proof fully exploits analytic solutions to the differential equation which are not available for the nonlinear, cylindrical Poisson-Boltzmann equation.
Walcott's Discovery of Middle Ordovician Vertebrates

Paleozoic fish remains were identified by T. W. Stanton in 1890 at Canon City, Colorado, but it remained for Walcott to recognize the significance of their great antiquity. After a hurried trip in December 1890, he was able to date them authoritatively as Middle Ordovician (Trentonian) by the presence of associated and overlying marine invertebrates. Fieldwork by S. W. Loper the following year, and by Walcott in 1892, added additional vertebrate specimens and verified Walcott's conclusions as to age. Walcott's 1892 paper, which significantly pushed back the record of antiquity of vertebrate life, was well known to European authorities but was essentially ignored by them because the age of the beds was questioned; the fossils were assumed to be similar to the fish described from the "Old Red" and therefore, Devonian. Further, discovery of these remains in sandstone somehow led to the assumption, common for many years, that vertebrates originated in fresh water. In spite of initial skepticism, Walcott's fos...
Theology as Art Form

I agree with Gordon Kaufman that we need an alternative to the viewpoint that the work of theology is primarily adaptive and responsive. His proposals create the prospect that theology can be understood, more and more, as a constructive and imaginative endeavor. And this, I believe, is all to the good. I like what he has suggested very much. And I appreciate the spirit in which it is suggested. Indeed, I believe it is one of the most refreshing spirits or temperaments within Christian theology today. And I am being careful when making such appraisals. However, at a certain point, some matters become unclear to me. For example, when considering the scope of the work of the imagination, I am not always certain that Dr. Kaufman makes a clear distinction between what is and what should be. Some of the time he is making recommendations about what he wishes theology would become. And some of the time he is engaged in description: this is the way theology functions even if those who are engaged in it are not always conscious that this is what is occurring. The difference between descriptive and prescriptive is not always clear. My hunch is that Dr. Kaufman is actually seeking two intentions simultaneously. But the dual focus leads to some confusion, as, for example, in the following statement:
The F-Box Protein ZEITLUPE Confers Dosage-Dependent Control on the Circadian Clock, Photomorphogenesis, and Flowering Time

As an F-box protein, ZEITLUPE (ZTL) is involved in targeting one or more substrates for ubiquitination and degradation via the proteasome. The initial characterization of ZTL suggested a function limited largely to the regulation of the circadian clock. Here, we show a considerably broader role for ZTL in the control of circadian period and photomorphogenesis. Using a ZTL-specific antibody, we quantitated and characterized a ZTL dosage series that ranges from a null mutation to a strong ZTL overexpressor. In the dark, ztl null mutations lengthen circadian period, and overexpression causes arrhythmicity, suggesting a more comprehensive role for this protein in the clock than previously suspected. In the light, circadian period becomes increasingly shorter at higher levels of ZTL, to the point of arrhythmicity. By contrast, hypocotyl length increases and flowering time is delayed in direct proportion to the level of ZTL. We propose a novel testable mechanism by which circadian period and amplitude may act together to gate phytochrome B‐mediated suppression of hypocotyl. We also demonstrate that ZTL-dependent delay of flowering is mediated through decreases in CONSTANS and FLOWERING LOCUS T message levels, thus directly linking proteasome-dependent proteolysis to flowering.
Imaging joints for calcium pyrophosphate crystal deposition: a knock to the knees

With advanced age, articular calcium pyrophosphate crystal deposition (CPPD) is common. Defining who has CPPD is of growing importance, given increases in longevity in many countries and the frequent association of chondrocalcinosis with osteoarthritis. Chondrocalcinosis detected by plain radiography serves as a major screening tool, but how many and which sites to screen have not been adequately defined in the past. The work of Abhishek and colleagues in the previous issue of Arthritis Research and Therapy sheds new light on the incomplete information from knee radiographs, and helps position us to learn more about the epidemiology, pathophysiology, diagnosis, and clinical impact of CPPD.
Potent inhibition of human apurinic/apyrimidinic endonuclease 1 by arylstibonic acids.

Human apurinic/apyrimidinic endonuclease (Ape1) plays an important role by processing the >10,000 highly toxic abasic sites generated in the genome of each cell every day. Ape1 has recently emerged as a target for inhibition, in that its overexpression in tumors has been linked with poor response to both radiation and chemotherapy and lower overall patient survival. Inhibition of Ape1 using siRNA or the expression of a dominant-negative form of the protein has been shown to sensitize cells to DNA-damaging agents, including various chemotherapeutic agents. However, potent small-molecule inhibitors of Ape1 remain to be found. To this end, we screened Ape1 against the NCI Diversity Set of small molecules and discovered aromatic nitroso, carboxylate, sulfonamide, and arylstibonic acid compounds with micromolar affinities for the protein. A further screen of a 37-compound arylstibonic acid sublibrary identified ligands with IC50 values in the range of 4 to 300 nM. The negatively charged stibonic acids act by a partial-mixed mode and probably serve as DNA phosphate mimics. These compounds provide a useful scaffold for development of chemotherapeutic agents against Ape1.
Perceived gender-based barriers to careers in academic surgery

Abstract Background Women represent roughly 50% of US medical students and one third of US surgery residents. Within academic surgery departments, however, women are disproportionately underrepresented, particularly at senior levels. The aim of this study was to test the hypothesis that female surgeons perceive different barriers to academic careers relative to their male colleagues. Methods A modified version of the Career Barriers Inventory–Revised was administered to senior surgical residents and early-career surgical faculty members at 8 academic medical centers using an online survey tool. Likert-type scales were used to measure respondents' agreement with each survey item. Fisher's exact test was used to identify significant differences on the basis of gender. Results Respondents included 70 women (44 residents, 26 faculty members) and 84 men (41 residents, 43 faculty members). Women anticipated or perceived active discrimination in the form of being treated differently and experiencing negative comments about their sex, findings that differed notably from those for male counterparts. Sex-based negative attitudes inhibited the career aspirations of female surgeons. The presence of overt and implicit bias resulted in a sense that sex is a barrier to female surgeons' career development in academic surgery. No differences were observed between male and female respondents with regard to career preparation or structural barriers. Conclusions Female academic surgeons experience challenges that are perceived to differ from their male counterparts. Women who participated in this study reported feeling excluded from the dominant culture in departments of surgery. This study may help guide transformative initiatives within academic surgery departments.
Statistical methods to correct for verification bias in diagnostic studies are inadequate when there are few false negatives: a simulation study.

A common feature of diagnostic research is that results for a diagnostic gold standard are available primarily for patients who are positive for the test under investigation. Data from such studies are subject to what has been termed "verification bias". We evaluated statistical methods for verification bias correction when there are few false negatives. A simulation study was conducted of a screening study subject to verification bias. We compared estimates of the area-under-the-curve (AUC) corrected for verification bias varying both the rate and mechanism of verification. In a single simulated data set, varying false negatives from 0 to 4 led to verification bias corrected AUCs ranging from 0.550 to 0.852. Excess variation associated with low numbers of false negatives was confirmed in simulation studies and by analyses of published studies that incorporated verification bias correction. The 2.5th – 97.5th centile range constituted as much as 60% of the possible range of AUCs for some simulations. Screening programs are designed such that there are few false negatives. Standard statistical methods for verification bias correction are inadequate in this circumstance.
Cancellation of Passive Intermodulation Distortion in Microwave Networks

Passive nonlinearities in high-power transmit/receive wireless systems cause undesirable transfer of power from high-power transmit carriers to the receive band, causing levels of interference and distortion that can severely limit or debilitate the system. This paper proposes a method of cancellation that allows for reduction of nonlinear distortion due to passive nonlinearities in high-power wireless systems. We verify the method by experiment, resulting in almost 40 dB of cancellation of nonlinear distortion in a high-power radio frequency system, effectively eliminating the reflected passive intermodulation from the system.
Adenocarcinoma of the small bowel: A study of 37 cases with emphasis on histologic prognostic factors

PURPOSE: Primary small-bowel adenocarcinoma is uncommon. There are few large studies that have evaluated the prognostic impact of clinical and pathologic parameters. The purpose of this study was to perform a comprehensive analysis of the Cleveland Clinic experience with small-bowel adenocarcinoma, with emphasis on histopathologic parameters as prognostic indicators. METHODS: Thirty-seven cases of primary small-bowel adenocarcinomas resected at the Cleveland Clinic between 1978 and 1999 were retrospectively studied. Metastatic tumors and those arising from the biliary system were excluded from analysis. Clinical and pathologic data were recorded and their impact on prognosis was evaluated by either Kaplan-Meier or Cox proportional hazards analysis. RESULTS: The cohort included 25 males, and the age range was 24 to 82 (mean, 56) years. Tumor location was duodenum (18), jejunum (10), ileum (2), and site not specified (7). Patients most frequently presented with abdominal pain (48 percent), anemia (39 percent) and small-bowel obstruction (33 percent). Underlying conditions included Crohn’s disease (4) and familial adenomatous polyposis (2). Overall survival was 52 and 47 percent at 5 and 10 years, respectively, with a mean follow-up of 50.5 (range, 0.5–184) months for all patients. Features found to be negative prognostic factors for survival were positive surgical margins (P < 0.001), extramural venous spread (P < 0.001), lymph node metastases (P = 0.038), poor tumor differentiation (P = 0.015), depth of tumor invasion (P = 0.023), and history of Crohn’s disease (P < 0.001). Age, gender, tumor size, growth pattern, lymphocytic host response, and adjuvant therapy did not affect survival. CONCLUSIONS: Pathologic features, including positive surgical margins, extramural venous spread, positive lymph nodes, poor tumor differentiation, depth of tumor invasion, and history of Crohn’s disease, are of major prognostic significance in small-bowel adenocarcinoma. Although many of these prognostic features are similar to the ones used for colorectal adenocarcinoma, they are easily applicable and reproducible for small-bowel adenocarcinomas. This is important considering the often dismal prognosis of small-bowel adenocarcinoma.
Evidence That Autobiographic Memory Retrieval Does Not Become Independent of the Hippocampus: An fMRI Study Contrasting Very Recent with Remote Events

Traditional consolidation theory, which seeks to explain how new memories are incorporated into the preexisting neural architecture, stipulates that the hippocampus plays a time-limited role in this process. However, although there is abundant research showing that the hippocampus is necessary for the initial (encoding) phase, there is very little experimental evidence with human subjects proving that the structure ceases to play a role in the retrieval of episodic items from memory stores. To test this hypothesis, we investigated recall activation associated with recent memories (2.5 days) versus remote memories (mean of 8 years) using functional magnetic resonance imaging. In accordance with the multiple memory trace theory, recall of consolidated autobiographic information, represented by the remote condition, was not independent of the hippocampus. Both types of memory retrieval produced significant activation in parahippocampal, prefrontal, and midtemporal gyri, the parietal–temporal junction, and a medial region of cortex spanning the posterior cingulate and precuneus gyri. However, where recent events activated bilateral regions of the caudate nucleus, remote events yielded significantly greater activation within the hippocampus proper. The results challenge traditional consolidation theory, which would predict greater hippocampal activity for recent events. Furthermore, they highlight the interplay between multiple memory systems in the brain. We argue that our particular question format, which encouraged depth of recall and did not require a prescan interview, as well as our delineation of the recent and remote time periods, were the determining factors for the observed pattern of hippocampal activation.
Osteoarthritis: An Update on Data Currently Reshaping Practice

Osteoarthritis is common, has considerable health consequences, and will affect increasing numbers of persons in coming years. Nonpharmacological interventions are of paramount importance in achieving adequate symptom control. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) play a pivotal role in osteoarthritis pharmacotherapy. Acetaminophen, due to its safety profile, should be adequately trialed before resorting to NSAIDs. NSAIDs and celecoxib, a selective inhibitor of cyclooxygenase-2, should be selected thoughtfully so as to balance the likelihood of treatment success with gastrointestinal bleeding and cardiovascular events. Celecoxib may be used when the risk for gastrointestinal bleeding is high and the risk of cardiovascular events low. Otherwise, NSAIDs, usually naproxen, should be paired with a gastroprotective agent. Topical NSAIDs, including a recently approved diclofenac patch and gel, may also be useful when systemic exposure is undesirable. The role of glucosamine and chondro...