cssi/SciSciGPT-SciSciNet huggingface dataset:
A new, more versatile, optical switching helical polycarbodiimide capable of thermally tuning polarizations ±359°

An in depth study of newly synthesized polycarbodiimides containing asymmetric aryl pendant groups has been performed. The focus of this study was to create new polymers capable of the low-energy, reversible, solvo-, and thermocontrollable conformational switching phenomenon previously discovered. Of the polymers synthesized, one polymer, N-(1-naphthyl)-N′-(n-octadecyl) polycarbodiimide, Poly-5, has been found to undergo reversible optical switching in various solvents, each of which alter the temperature at which the switching is observed. The switching is not due to helical inversions, but instead due to synchronous rearrangement of polyarene pendant groups around the helical backbone. This is further shown by anisotropic changes of the aromatic chemical shifts using variable temperature 1H NMR through the observed thermal switching range in THF-d8. The net change in specific optical rotation reaches a remarkable 1700° and changes in the direction of rotation. The polymer system is tunable and capable o...
Proactive displays & the experience UbiComp project

The proliferation of sensing and display technologies creates opportunities for proactive displays that can sense and respond appropriately to the people and activities taking place in their vicinity. A conference provides an ideal context in which to explore the use of proactive displays, as attendees come together for the purpose of mutual revelation, eager both to learn more about others and what others are doing and to tell others about themselves and what they are doing. We will deploy a suite of proactive display applications that can aid and abet this desire for mutual revelation in the context of a paper presentation session, a demonstration and poster session, and informal break areas at the conference.
Inactivation modifiers of Na+ currents and the gating of rat brain Na+ channels in planar lipid membranes.

Rat brain Na+ channels whose inactivation process had been removed either by batrachotoxin (BTX) or veratridine (VT) were reconstituted into planar lipid membranes. The voltage dependence of the open probability (Po) of the channel, of the opening and closing rate constants, and the conductance and relative permeability for Na+ and K+ were studied in voltage-clamp conditions in the presence of agents known to modify the inactivation of Na+ currents. In relation to alkaloids (BTX, VT, and aconitine), it was found that once a Na+ channel was modified by BTX or VT, the addition of another alkaloid did not change further the gating and permeation properties of the channel over a period of about 1 h. Once the inactivation process of the channels is removed by BTX, the addition of a proteolytic enzyme (trypsin) or an halogenated compound (chloramine-T, CT) induced profound and specific modifications on the opening and closing events of Na+ channels: (1) the voltage dependence of the channel Po shifted to more hyperpolarized potentials; (2) this voltage shift can be explained by equal hyperpolarizing voltage shifts of the opening and closing rate constants of the channel; (3) although the gating properties of the channel were modified by these compounds, the permeation properties of the channel, as evaluated by the conductance and the selectivity to Na+ and K+ ions, were unaltered; (4) trypsin and CT were active only in the intracellular side of the channel and were irreversible within the time course of the experiments, suggesting covalent modifications of the channel. Inactivation modifiers also affected the gating of toxin-activated single Na+ channels. This alteration is compatible with a simple increase in the intracellular potential as seen by the voltage sensor of the channel.
Multicanonical Molecular Dynamics Simulations of Low-Molecular-Weight Peptide Oligomers

We present simulation results for small peptide oligomers (dimers through hexamers) using the multicanonical simulation algorithms Replica Exchange Statistical Temperature Molecular Dynamics. This algorithms use biased dynamics to overcome sampling problems related to broken ergodicity at low temperatures. Changes in the Potential Energy Surface of the system as it grows from a single molecule to a small oligomer are discussed. Each peptide is represented using a coarse-grained model and has an alpha-helix as its native state. We show for dimers that, at low temperatures, both peptides are helical; at high temperatures, both peptides are random coils; and at intermediate temperatures, one peptide is folded while the other adopts an extended configuration that minimizes the solvent exposed surface area. Dimerization causes one peptide to become more stable and fold at a higher temperature than an isolated monomer while the other peptide becomes less stable and folds at a lower temperature than an isolated monomer. This effect is due to the solvation of the stabilized molecule by the unfolded, destabilized molecule. We show that this effect is stronger in larger oligomers and results in multiple solvated peptides that are substantially more stable than the isolated monomer at the expense of multiple molecules that are thermally destabilized. The consequences of this effect are discussed in the context of molecular crowding and of protein misfolding and aggregation.
Risk and protective factors that affect adolescent reproductive health in developing countries: a structured literature review

The primary focus of this article is to determine which risk and protective factors are most important to adolescent reproductive health in developing countries. A comprehensive and systematic literature search was conducted on studies that examined factors in relation to the following outcomes: ever had premarital sex, condom use, pregnancy, early childbearing, sexually transmitted infections, and HIV. While the search identified over 11,000 publications, only 61 were retained for the final analysis. The results show that factors which were significantly associated to the outcomes were primarily related to the adolescents themselves. In fact, very few factors outside the individual were found to be related to sexual risk behaviours. This contrasts to similar research conducted among youth samples in the US. While this review confirms the strong need for a broader research base on the risk and protective factors related to adolescent sexual and reproductive health in developing countries, it also does identify key factors that can be addressed through innovative programmes and policies to help improve adolescent reproductive health in the developing world.
FTN topology and protocols

Abstract We have developed a network called FTN that satisfies the requirements for a large class of fault tolerant applications in distributed processing. (N denotes the number of devices and m = ⌈log2N⌉). The network has a high fault tolerance: up to m−2 faulty processors can be tolerated. The fault tolerance is high and optimal. The criteria of optimality is the following: the number of vertex disjoint paths is equal to the minimal degree in the graph (m−1). We have developed algorithms to provide routing in both faulty and nonfaulty systems. The paths generated by the algorithms are nearly the shortest paths for any two source and destination processors. The network can be constructed for a system of an arbitrary size. We developed an algorithm which can add a new processor at the small cost of modifying only O(m) edges. The O(m) diameter implies a low transit delay. A multiplexing/demultiplexing protocol can utilize up to m−1 nonblocking paths between any two processors to achieve a high throughput. In general the network has much better fault tolerance than the recently reported Incomplete Cube, can be designed for any number of processors in contrast to the Boolean Cube, and it has a significantly lower cost than the Generalized Hypercube network in terms of the link count.
Immunohistochemical demonstration of prostatic origin of metastases

Abstract An immunoperoxidase technique for prostate specific acid phosphatase was performed on 14 lymph node metastases of prostatic carcinoma and 13 cases of metastatic adenocarcinoma from other primary sites. Eleven metastatic prostate carcinomas showed diffuse strongly positive immunostain and one showed focal weak positivity. Two prostatic and all other metastatic carcinomas were negative. Thus, the method is found to be extremely specific (100 per cent) and to show a high degree of sensitivity (86 per cent) for the demonstration of the prostatic origin of lymph node metastases.
Vaso-vagal reactions in an ambulatory surgery center

This prospective study was undertaken to determine the incidence and factors predisposing to vaso-vagal reactions during venous cannulation in an ambulatory surgery population. In 141 ambulatory surgery patients, signs and symptoms of a reaction together with mean arterial pressure and heart rate were recorded at 1-min intervals during and for 6 min after venous cannulation. Overall, 10.6% of patients were symptomatic (95% confidence interval [CI] 6%-17%). The incidence was 16.6% (95% CI 8.4%-24.9%) in patients < or = 40 yr and 33.3% (95% CI 6.7%-60.0%) with a prior fainting history. Young age, duration or number of attempts at venous cannulation, and fainting history were independently associated with increased risk of a reaction (P < 0.03-0.004 by multiple repression analysis). Minimum mean arterial pressure was less in symptomatic patients than in those who were asymptomatic (58 mm Hg +/- 11.3 SD versus 82 mm Hg +/- 14.3 SD, P < 0.0001). We conclude that reactions occur commonly, particularly in the young or in patients with a history of fainting. Reactions are typically associated with significant hypotension that may require treatment.
More on limit theorems for iterates of probability measures on semigroups and groups

In this paper, we continue earlier works of one of the authors on vague convergence of the sequence βk,n=βk+1 *...*βn, where βn is a sequence of probability measures on semigroups or groups. Typical results in this paper are: Theorem. Let S be a locally compact noncompact second countable group such that \(S = \overline {\bigcup\limits_{n = 1}^\infty {S_\beta ^n ,} } S_\beta\) being the support of a probability measure β on S. Suppose there exists an open set V with compact closure such that x−1Vx=V for every x∈S. Then for all compact sets K, sup{βn(Kx): x∈S→0 as n→∞. Theorem. Let S be an at most countable discrete group. Let βn be a sequence of probability measures on S. Then for all nonnegative integers k, the sequence βk,n converges vaguely to some probability measure if and only if there exists a finite subgroup G such that the series \(\sum\limits_{n = 1}^\infty {\beta _n } (S - G) s>0 for all n, e being the identity.
Composition domains in monoterpene secondary organic aerosol

The composition and structure of freshly formed oligomers in alpha- and beta- pinene SOA are studied with high performance mass spectrometry to provide insight into the SOA formation mechanism. Van Krevelen plots (H:C ratio vs O:C ratio) are interpreted in the context of distinct structural domains that correspond to separate oligomer formation routes. The domain containing most of the signal intensity encompasses elemental formulas that correspond to oligomerization reactions of intermediates and/or stable molecule monomers produced by ozonolysis of the precursor. While oligomers involving reactive intermediates from the hydroperoxide channel dominate the product distribution, products are also observed that uniquely map to the stable Criegee intermediate and/ or combinations of stable molecule monomers. A second domain encompasses molecules having lower H:C ratios but similar O:C ratios to the first domain. Many of the products observed in this domain have double bond equivalents greater than the maximum number possible when forming dimers by standard reaction mechanisms and are interpreted in the context of repeated self-reactions of alkoxy/peroxy radicals. A third domain encompasses molecules having very high H:C and O:C ratios consistent with polymerization of formaldehyde and/or acetaldehyde. These domains remain distinguishable from experiment to experiment and among different extraction solvents (50/50 methanol-water, 50/50 acetonitrile-water,100% water).
Elastic distortion fields in the ternary compound K1−xRbxC8

Abstract We have studied the binary compound formation K 1− x Rb x C x by in situ X-ray (00 l ) scans on HOPG material. The elastic distortion field parallel to the c -axis was monitored by the change of the Bragg angle. Simultaneously, we determined the ternary composition by the intensity ratio of the (001) and (002) reflections. The measurements reveal a strong deviation from Vegard's rule of lattice parameter changes in binary alloys. The width of the (002) reflection, measured at a sample temperature of 320°C, is a function of the binary concentration and shows a maximum at x = 0.7. In the small concentration region ( x x >0.9) we have determined the component of the double force tensor normal to the planes for K and Rb defects, which is in both cases 0.37 eV.
Second-order phase field asymptotics for unequal conductivities

We extend Karma and Rappel's improved asymptotic analysis of the phase field model to different diffusivities in solid and liquid. We consider both second-order "classical" asymptotics, in which the interface thickness is taken much smaller than the capillary length, and the new "isothermal" asymptotics, in which the two lengths are considered comparable. In the first case, if the phase field model is required to be gradient flow for an entropy functional, then for unequal diffusivities it is impossible to construct a phase equation with finite kinetics which converges with second-order accuracy to a Gibbs--Thomson equilibrium condition with infinitely fast kinetics. In the second case, some error terms are pushed to higher orders, and it is easy to eliminate the remaining errors with finite phase kinetics.
Use of consensus information in prediction of behavior

Abstract This research examined the effects of two factors on the use of consensus information in making predictions about the behavior of a target person. Subjects first read a description of a condition in Darley and Latane's ( Journal of Personality and Social Psycholog , 1968, 8 , 377–383) bystander intervention experiment in which actual participants rarely helped the victim (a socially undersirable behavior). The two factors of interest were: (a) social desirability of the consensus information (subjects were shown the actual distribution of behavior in the Darley and Latane study, no distribution, or a distribution opposite to that obtained by Darley and Latane), and (b) information about the personality and background of a target member of the original experimental population (subjects either read a description of the target person or they did not). After receiving the above information, subjects predicted the target person's behavior in the experiment. The impact of consensus information on prediction of behavior was greater when social desirability of the consensus information was high rather than low, and when subjects did not read a description about the target person. The different manners in which consensus information can be used were discussed.
Conjugate Heat Transfer Modeling of a Film-Cooled, Flat-Plate Test Specimen in a Gas Turbine Aerothermal Test Facility

The aerothermal test facility at the National Energy Technology Laboratory (NETL) provides experimental data at realistic gas turbine conditions to enable the development of advanced film cooling strategies for future gas turbine components. To complement ongoing experimental studies, Fluent computational fluid dynamics (CFD) models have been developed to provide a framework for comparison of cooling strategies and to provide fundamental understanding of the fluid dynamic and conjugate heat transfer (CHT) processes occurring in the experiments.The results of a parametric study of the effects of mesh density, near-wall refinement, wall treatment, turbulence model and gradient discretization order on the CHT predictions are presented, and the simulation results are compared to experimental data. A flat plate test specimen with a single row of laidback fan-shaped film cooling holes was modeled at a process pressure of 3 bar, a process gas flow rate (m) of 0.325 kg/s (Re ≈ 100,000) and a blowing ratio (M) of 2.75. Three polyhedral mesh cases and three turbulence models (Realizable k-e, SST k-ω and RSM Stress-ω) were implemented with enhanced wall treatment (EWT) and 1st-order and 2nd-order gradient discretization.The results show that the choice of turbulence model will have little effect on the results when utilizing the finest mesh case and 2nd-order discretization. It was also shown that the SST k-ω turbulence model cases showed minimal mesh sensitivity with 2nd-order discretization, while the Re k-e turbulence model cases were more sensitive to mesh density and near-wall refinement. The results thus indicate that the SST k-ω turbulence model can predict the convective heat transfer adequately with a relatively coarse mesh, which will save computational resources for later inclusion of radiative heat transfer effects to provide comprehensive CHT predictions.Copyright © 2013 by ASME
A new class of mixed-valence systems with orbitally degenerate organic redox centers. Examples based on hexa-rhenium molecular prisms

The ligand-centered mixed-valence (LCMV) properties of two supramolecular complexes are reported: triangular prisms of the form ([Re(CO)3]2X)3-μ,μ‘,μ‘ ‘-[tPyTz]2, where X is 2,2‘-bisbenzimidazolate (1) or a pair of benzylthiols (2), and tPyTz is tri-(4-pyridyl)-1,3,5-triazine. Cyclic voltammetry demonstrates that the redox-accessible bridging ligands, tPyTz, are reduced in sequential, one-electron reactions. The singly reduced prisms, which represent an unusual type of mixed-valence compound in which the tPyTz ligands themselves are the redox centers, show intense, broad intervalance transfer (IT) bands in the NIR, consistent with highly coupled MV species. Electroabsorption (Stark spectroscopy) measurements reveal small dipole moment changes associated with intervalence excitation (|Δμ12| = 0.30 ± 0.02 eA for 1- and 0.48 ± 0.02 eA for 2-), as well as noncollinear transition dipole moment (μ12) and dipole moment change vectors (ζ ≈ 45°). DFT electronic structure calculations support this unusual result, ...
Micromechanical toughness test applied to NiAl

Abstract A microscratch technique for determining the fracture toughness of brittle intermetallics is presented. Advantages include very small sample sizes and multiple tests on a single, flat polished surface. The fracture toughnesses of single-crystal NiAl in {001}〈100〉, {001}〈110〉, {110}〈110〉, and {110}〈100〉 crack orientations were evaluated using this technique. The results of the scratch testing are compared with measurements on small compact tension samples. Also, transmission electron microscopy is used to help explain the dislocation character of the resulting plastic zones in samples tested. Lastly, a model for determining the dislocation velocity during nanoindentation is presented to help understand the ductile-brittle transition temperature of semibrittle materials.
Multicriteria Optimization Method for Network-Level Bridge Management:

A multicriteria optimization method for analyzing important capital investment decisions involved in managing bridge infrastructure is presented. The condition assessment and decision variables of the method can be adapted to analyze a population of small and medium-size bridges or a population of spans of a large bridge. Condition ratings of various bridge structural elements are used to assess the condition needs of four major components. Subsequent use of this information leads to characterization of bridge condition by defining bridge states. State increment models are used to identify suitable treatment options for each state and predict the variable time over which state increments (or transitions) occur. These state increment models are incorporated into an optimization method that has three major steps: (a) identification of objective functions representing the multiple decision criteria, (b) assessment of the importance of each objective in achieving the numerical goals targeted by decision maker...
A lipopolysaccharide binding heteromultivalent dendrimer nanoplatform for Gram negative cell targeting

We report on the practicality of a heteromultivalent design strategy for a nanoplatform that targets lipopolysaccharide molecules (LPS) present on the surface of Gram-negative bacteria. This design is based on the conjugation of a poly(amido amine) (PAMAM) dendrimer with two types of ligands, each having distinct affinities: (i) polymyxin B (PMB) as a primary high affinity ligand; (ii) a PMB-mimicking dendritic branch as an auxiliary low affinity ligand. Co-conjugation of these two ligands maximizes the efficiency of the primary ligand even when the primary ligand is present at a low valency on the nanoplatform (mean nPMB ≈ 1). By performing surface plasmon resonance studies using a LPS-immobilized cell wall model, we identified an ethanolamine (EA)-terminated branch as the auxiliary ligand that promotes binding avidity via heteromultivalent association. PMB conjugation of the dendrimer with excess EA branches led to LPS avidity two orders of magnitude greater than unconjugated PMB. Such tight binding observed by SPR corresponded well with adsorption to E. coli cells and with potent bactericidal activity in vitro.
Electrochemical analysis of parathion-ethyl using zirconium oxide–laponite nanocomposites-modified glassy carbon electrode

A simple, cost–effective electrode surface modified with a mixture of laponite clay and zirconium oxide (laponite–ZrO2) gel nanocomposites has been developed for the detection of parathion-ethyl pesticide. Different composition ratios of laponite–ZrO2 gel were used to modify the surface of glassy carbon (GC) electrode. The fabricated electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and attenuated total internal reflectance infrared spectroscopy. Cyclic voltammetry and differential pulse voltammetry were employed to investigate the modified laponite–ZrO2 electrode toward the electrochemical oxidation of several organophosphate compounds. The obtained results showed that the laponite–ZrO2 nanocomposites-modified GC electrodes have improved the sensitivity and selectivity of parathion-ethyl detection with a limit of detection as low as 1.6 ng mL−1 in the linear range of 0–58.3 ng mL−1 (R 2 = 0.994). Furthermore, the modified electrodes showed good stability at 71.6 ± 3.2 % after 14 days with the relative standard deviation of 4.36 % (n = 20).
Ganglioside GM1-Mediated Amyloid-beta Fibrillogenesis and Membrane Disruption†

There is increasing evidence that a class of cell membrane glycolipids, gangliosides, can mediate the fibrillogenesis and toxicity of Alzheimer's disease amyloid-beta peptide (Abeta). Using lipid monolayers and vesicles as model membranes, we measured the insertion of Abeta into 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-ganglioside GM1 monolayers to probe Abeta-GM1 interactions, imaged the effects of Abeta insertion on monolayer morphology, and measured the rate of Abeta fibril formation when incubated with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)-GM1 vesicles. Furthermore, the location of Abeta association in the monolayer was assessed by dual-probe fluorescence experiments. Abeta exhibited direct and favorable interactions with GM1 as Abeta insertion monotonically increased with GM1 concentration, despite increases in monolayer rigidity at low GM1 levels. At low GM1 concentrations, Abeta preferentially inserted into the disordered, liquid expanded phase. At higher GM1 concentrations, Abeta inserted more uniformly into the monolayer, resulting in no detectable preferences for either the disordered or condensed phase. Abeta insertion led to the disruption of membrane morphology, specifically to the expansion of the disordered phase at low GM1 concentrations and significant disruption of the condensed domains at higher GM1 concentrations. During incubation with POPC vesicles containing physiological levels of GM1, the association of Abeta with vesicles seeded the formation of Abeta fibrils. In conclusion, favorable interactions between Abeta and GM1 in the cell membrane may provide a mechanism for Abeta fibrillogenesis in vivo, and Abeta-induced disruption of the cell membrane may provide a pathway by which Abeta exerts toxicity.
RIGHT VENTRICLE TRANSCRIPTIONAL PROFILING IN HUMAN HEART FAILURE

The right ventricular (RV) transcriptome in human heart failure (HF) has not been widely reported. We performed RNAseq (30M target reads/cDNA library, paired-end 50 bp sequencing by Illumina HiSeq 25009) on 5 unused donor RVs (DON) and 22 explanted HF RVs. We used a novel sum of ranks approach
Regulation of Armadillo by a Drosophila APC Inhibits Neuronal Apoptosis during Retinal Development

Abstract We find that inactivation of a Drosophila homolog of the tumor suppressor APC (D-APC) causes retinal neuronal degeneration and pigment cell hypertrophy, a phenotype remarkably similar to that found in humans with germline APC mutations. Retinal degeneration in the D-APC mutant results from apoptotic cell death, which accompanies a defect in neuronal differentiation. Reduction in the Drosophila β-catenin, Armadillo (Arm), rescues the differentiation defect and prevents apoptosis in the D-APC mutant, while Arm overexpression mimics D-APC inactivation. A mutation in dTCF, the DNA-binding protein required in Arm-mediated signal transduction, can eliminate the cell death without rescuing the differentiation defect in D-APC mutants. Uncoupling of these two Arm-induced processes suggests a novel role for the Arm/dTCF complex in the activation of apoptosis.
Temperature Dependence of the Electrical Conductivity of Single Crystal Quinolinium (TCNQ)2

Abstract Previous electrical,(1) optical(2) and magnetic susceptibility(3) data of the complex anion-radical salt quinolinium (TCNQ)2 have been interpreted in terms of a model in which the close face to face stacking of TCNQ molecules allows the formally unpaired electron (one unpaired electron per two TCNQ molecules) to be completely delocalized over the entire TCNQ array producing a strongly degenerate electron gas. Specific evidence for this model comes from several sources: the X-ray data for other 1 : 2 complexes (e.g. triethylammonium (TCNQ)2 (4) tetraphenylphosphonium (TCNQ)2 (5)) show a face to face stacking of TCNQ with a closer than van der Waals separation between the molecular planes (no X-ray data are available for the quinolinium salt); the electrical conductivity for this complex is very high at room temperature (σ = 100 Ω−1 cm−1)l; the magnetic susceptibility is temperature independent from about 50 °K to 300 °K which has been interpreted as being due to Pauli paramagnetism(3) and the EPR ...
Decentralized cooperative control of multiple nonholonomic systems

This paper considers the cooperative control of multiple nonholonomic systems. Time-varying cooperative control laws are proposed with the aid of the results of the graph theory. The proposed control laws are decentralized and make the states of the group of systems converge to a moving point. By suitable control variables, the proposed control laws can make the state of each system converge to a small neighborhood of the origin. Robustness of the proposed control laws to communication delays is also considered. As an application of the proposed results, formation control of wheeled mobile robots is discussed. The simulation results show effectiveness of the proposed results.
Distal Interphalangeal Joint Arthrodesis

CURRENT OPINION Kirschner wires have high fusion rates but risk pin track infection. Intraosseous wires have also resulted in high fusion rates, but have the disadvantages of implant prominence and a secondary procedure for implant removal in some cases. Headless compression screws offer the potential benefit of stability across the arthrodesis site without implant prominence, but they have the disadvantages of difficulty achieving arthrodesis in flexion (if desired), size mismatch between the bone and screw, increased cost, potential nail deformity, screw cutout, screw breakage, and retained implant. Headed screws have also been used with high union rates, but have the disadvantage of prominent screw heads.
Low-Temperature Thermochronometry of Meteorites

Timing of accretion of the primary planetesimals in the early solar system has been investigated using short-lived (e.g., 26Al, 53Mn, 182Hf and 129I) and long-lived (e.g., 238U, 235U, 232Th and 147Sm) radionuclides. The first condensed objects in the solar system are known to be the calcium-aluminum-rich inclusions (CAIs) in chondrites (undifferentiated meteorites mainly composed of Fe- and Mg- bearing silicates), the most abundant meteorites found on Earth. The formation age of the CAIs was precisely determined by 207Pb/206Pb dating at ~4.56–4.57 Ga (Tilton 1988; Allegre et al. 1995; Amelin et al. 2002). Following the formation of the CAIs, more solids were rapidly accreted. Bodies grown to relatively large size (e.g., large terrestrial planets) experienced differentiation forming metallic cores, whereas smaller bodies of asteroids (e.g., parent bodies of chondritic meteorites) underwent relatively mild thermal metamorphism over the next ~15–20 Myr (summarized in Gilmour and Saxton 2001), followed by cooling to the their present thermal status. Thermal histories of asteroids and planets after primary crystallization or metamorphism have been the subject of considerable attention. One reason for this attention is because the deduced thermal histories provide key information on accretion processes, physical dimensions and heat budget of the early solar bodies. Using Ni distribution between two metallic phases, kamacite and taenite, Wood (1967) deduced cooling rates of ~2–10 °C/Ma at ~500 °C for ordinary chondrites, and showed how this information can be used to estimate the size of the parent body and original depth of individual meteorites in the parent body. Turner et al. (1978) deduced cooling rates at ~240 ± 120 °C by studying 40Ar/39Ar system in 16 unshocked chondrites, and suggested that these are from parent bodies with radii less than 30 km, or …
The Mentoring Partnership

Although long recognized, the importance of a mentor appears to be receiving renewed attention. The New England Journal ofMedicine recently published an article on attending physicians as role models.' The authors of the article identified several characteristics of excellent teach­ ers. Some of these features included an emphasis on the patient-physician relationship and a psychosocial perspec­ tive in clinical care, and others have emphasized enjoyment of teaching, greater time devoted to educating, teaching in clinical settings, providing feedback to learners, and ac­ tively building relationships with students. An editorial in Medical Education highlighted the importance of men­ toring throughout one's career, especially during profes­ sional transitions.' In the same volume, another editorial called for an examination of the effect of role models on students and junior staff and went on to describe the con­ cept of learning through caring.' It is estimated that fewer than half of physician-teachers exhibit professional characteristics residents want to emu­ late." However, those who do exhibit such worthy charac­ teristics can have a profound effect on the professional lives of their students. In this article, we review mentoring as a partnership that depends on the fit between teacher and student. We expand the discussion to include the concept of loss in the life cycles of these professional relationships. Background The word mentor is derived from the fictional character Mentor, tutor of Telemachus, in the Odyssey of Homer. S Mentor was a wise and faithful friend ofOdysseus, King of Ithaca. When Odysseus departed for the siege of Troy, he entrusted his infant son, Telemachus, to Mentor. Mentor was largely responsible for the child's education, shaping his character and instilling values. In Mentor's presence, Telemachus matured to make decisions independently. Thus, Mentor was viewed as the transitional figure in Telemachus's life during his journey from youth to man­ hood. Although the concept of mentor is ancient, it continues to be useful in many areas, including the development of
X-ray-induced Abnormal Differentiation of the Epithelium of the Small Intestine in the Mouse

SummaryAfter 2500 r of x-irradiation the cells that originally occupied the crypts (stem cells) migrate onto the villus. These abnormal stem cells form the final protective barrier between intestinal lumen and the tissues.As the population migrates, the cells undergo differential hypertrophy. The more mitotically-active cells in the crypt that are least differentiated show greatest enlargement. The most differentiated and least mitotically-active epithelial cells show least hypertrophy. We propose that stem-cell hypertrophy may be an abnormal form of differentiation, which results primarily from radiation-induced mitotic inhibition.
The long-term effects of intimate partner violence on adolescent mothers’ depressive symptoms

Adolescent mothers are at high risk of experiencing intimate partner violence (IPV) which may increase their likelihood of depressive symptoms in adulthood, yet little is known about the long-term effects of IPV on adolescent mothers' trajectories of depressive symptoms. The study reported here uses prospective data spanning 14 years from a study of 229 adolescent mothers from Washington State, USA to evaluate the effects of adolescent exposure to IPV on the trajectories of depressive symptoms over time, as well as the likelihood of depressive symptoms at age 28 years. After controlling for levels of economic insecurity, the results indicate that adolescent IPV and an early vulnerability to depression were significantly related to the intercept, but not the slope of the adult depressive symptom trajectories. Both cumulative and concurrent IPV predicted the likelihood of depressive symptoms at age 28 years. Follow-up analyses indicate that adolescent IPV is associated with greater levels of adult IPV, and that women who report both adolescent and adult IPV have the highest mean levels of depressive symptoms. These findings suggest that exposure to IPV in adolescence may alter the life course of young women, increasing their risk for continuing exposure to intimate partner violence in adulthood and its concomitant negative mental health effects. Efforts aimed at prevention and early intervention in IPV among adolescent mothers are important components of the clinical care of young mothers.
Characterization of Aura TES carbonyl sulfide retrievals over ocean

Abstract. We present a description of the NASA Aura Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm for oceanic observations, along with evaluation of the biases and uncertainties using aircraft profiles from the HIPPO (HIAPER Pole-to-Pole Observations) campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 and 500 hPa, (3) but have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. We estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.
Transendothelial Migration of Megakaryocytes in Response to Stromal Cell-derived Factor 1 (SDF-1) Enhances Platelet Formation

Although thrombopoietin has been shown to promote megakaryocyte (MK) proliferation and maturation, the exact mechanism and site of platelet formation are not well defined. Studies have shown that MKs may transmigrate through bone marrow endothelial cells (BMEC), and release platelets within the sinusoidal space or lung capillaries. In search for chemotactic factor(s) that may mediate transmigration of MKs, we have discovered that mature polyploid MKs express the G protein–coupled chemokine receptor CXCR4 (Fusin, LESTR). Therefore, we explored the possibility that stromal cell–derived factor 1 (SDF-1), the ligand for CXCR4, may also induce transendothelial migration of mature MKs. SDF-1, but not other CXC or CC chemokines, was able to mediate MK migration (ED50 = 125 pmol/liter). The MK chemotaxis induced by SDF-1 was inhibited by the CXCR4-specific mAb (12G5) and by pertussis toxin, demonstrating that signaling via the G protein–coupled receptor CXCR4 was necessary for migration. SDF-1 also induced MKs to migrate through confluent monolayers of BMEC by increasing the affinity of MKs for BMEC. Activation of BMEC with interleukin 1β resulted in a threefold increase in the migration of MKs in response to SDF-1. Neutralizing mAb to the endothelial-specific adhesion molecule E-selectin blocked the migration of MKs by 50%, suggesting that cellular interaction of MKs with BMEC is critical for the migration of MKs. Light microscopy and ploidy determination of transmigrated MKs demonstrated predominance of polyploid MKs. Virtually all platelets generated in the lower chamber also expressed CXCR4. Platelets formed in the lower chamber were functional and expressed P-selectin (CD62P) in response to thrombin stimulation. Electron microscopy of the cells that transmigrated through the BMEC monolayers in response to SDF-1 demonstrated the presence of intact polyploid MKs as well as MKs in the process of platelet formation. These results suggest that SDF-1 is a potent chemotactic factor for mature MKs. Expression of CXCR4 may be the critical cellular signal for transmigration of MKs and platelet formation.
Increasing Black Student Enrollment in Gifted Programs: An Exploration of the Pulaski County Special School District's Advocacy Efforts

An increasing amount of literature focuses on effective advocacy efforts that promote excellence in gifted education, yet educators know very little about successful advocacy efforts targeted to en...
Acute cardiovascular response to a single large intravenous dose of methylprednisolone and its effects on the responses to norepinephrine and isoproterenol.

The cardiovascular actions of single 10-pglkg iv doses of norepinephrine (NE) and isoproteronol (KO), before and after the administration of a single 30-mglkg iv dose of the glucocorticoid methylprednisolone (MP) (sodium succinate ester), were compared in adult cats. Methylprednisolone increased both systolic and diastolic pressures as well as the pulse pressure by approximately 50%. These steroid effects persisted unabated for the duration of the experiment (40 min). Heart rate was unaffected by MP. MP treatment significantly reduced the increase in systolic and diastolic pressures caused by NE. This MP effect was unrelated to the higher baselines for these two parameters caused by the steroid. The systolic blood pressure and positive chronotropic effects of IS0 were also significantly blunted by MP. These observations suggest that a single large dose of MP may cause a depression of cardiovascular a- and 8-1-receptor sensitivity. The results are discussed in relation to the actions of massive dose glucocorticoid administration in certain shock states and central nervous system trauma and stroke. Highdose administration of glucocorticoid,
A C(alpha)-H.O Hydrogen Bond in a Membrane Protein Is Not Stabilizing

Hydrogen bonds involving a carbon donor are very common in protein structures, and energy calculations suggest that Cα−H···O hydrogen bonds could be about one-half the strength of traditional hydrogen bonds. It has therefore been proposed that these nontraditional hydrogen bonds could be a significant factor in stabilizing proteins, particularly membrane proteins as there is a low dielectric and no competition from water in the bilayer core. Nevertheless, this proposition has never been tested experimentally. Here, we report an experimental test of the significance of Cα−H···O bonds for protein stability. Thr24 in bacteriorhodopsin, which makes an interhelical Cα−H···O hydrogen bond to the Cα of Ala51, was changed to Ala, Val, and Ser, and the thermodynamic stability of the mutants was measured. None of the mutants had significantly reduced stability. In fact, T24A was more stable than the wild-type protein by 0.6 kcal/mol. Crystal structures were determined for each of the mutants, and, while some struct...
Observations on Return Mapping Algorithms for Piecewise Linear Yield Criteria

This paper shows that for perfect plasticity, the closest point projection method (CPPM) and the cutting plane algorithm (CPA) for return mapping are exactly equivalent for piecewise linear yield criteria under both associated and nonassociated plastic flow. The paper demonstrates this by presenting closed-form expressions for returned stresses in terms of predicted stresses. A consequence of this exact approach is that the final stresses can be obtained in a single iteration. The equivalence of CPPM and CPA is further demonstrated numerically by comparing five previously published algorithms for return mapping to Mohr–Coulomb in a finite-element analysis of bearing capacity. The analyses also highlight issues relating to singularities that occur at the corners of the Mohr–Coulomb surface. It is shown that many of these problems can be avoided if the return mapping is performed in principal stress space as opposed to general stress space.
Survival of arthroaleuriospore-producing fungi in mice

Arthroaleuriosporous fungi (Gymnoascaceae and related fungi) are frequently isolated from organs and tissues of wild rodents. Survival of several such species after inoculation into mice was investigated. Fifteen arthroaleuriosporous fungi were inoculated intraperitoneally into mice. These mice were sacrificed at varying periods after inoculation. Selected organs were cultured on an appropriate medium to determine the presence of the fungi originally inoculated into the mice. The survival time of the fungi varied from 21 to 49 days after inoculation. Thirteen of these fungi were recovered only from the liver, spleen and enterics. Two of the fungi, Coccidioides immitis and Malbranchea dendritica were also recovered from lung tissue.Two arthroaleuriosporous fungi were passed serially through mice: Auxarthron reticulatum (three passages) and Malbranchea dendritica (four passages). Recoveries from these passages exceeded 35 percent for each passage. Recoveries were made even when no gross abnormalities were o...
Stochastic Dynamic Thermal Management: A Markovian Decision-based Approach

This paper proposes a stochastic dynamic thermal management (DTM) technique in high-performance VLSI system with especial attention to the uncertainty in temperature observation. More specifically, we propose a stochastic thermal management framework to improve the accuracy of decision making in DTM, which performs dynamic voltage and frequency scaling to minimize total power dissipation and on-chip temperature. A key characteristic of the framework is that thermal states are controlled by stochastic processes, i.e., partially observable semi-Markov decision processes. Collaborative optimization is considered with mathematical programming formulations to reduce operating temperature by using multi-objective design optimization methods. Experimental results with 32-bit embedded RISC processor demonstrate the effectiveness of the technique and show that the proposed algorithm ensures thermal safety under performance constraints.
Efficiency of a POD-based reduced second-order adjoint model in 4D-Var data assimilation

SUMMARY Order reduction strategies aim to alleviate the computational burden of the four-dimensional variational data assimilation by performing the optimization in a low-order control space. The proper orthogonal decomposition (POD) approach to model reduction is used to identify a reduced-order control space for a two-dimensional global shallow water model. A reduced second-order adjoint (SOA) model is developed and used to facilitate the implementation of a Hessian-free truncated-Newton (HFTN) minimization algorithm in the POD-based space. The efficiency of the SOA/HFTN implementation is analysed by comparison with the quasi-Newton BFGS and a nonlinear conjugate gradient algorithm. Several data assimilation experiments that differ only in the optimization algorithm employed are performed in the reduced control space. Numerical results indicate that first-order derivative methods are effective during the initial stages of the assimilation; in the later stages, the use of second-order derivative information is of benefit and HFTN provided significant CPU time savings when compared to the BFGS and CG algorithms. A comparison with data assimilation experiments in the full model space shows that with an appropriate selection of the basis functions the optimization in the POD space is able to provide accurate results at a reduced computational cost. The HFTN algorithm benefited most from the order reduction since computational savings were achieved both in the outer and inner iterations of the method. Further experiments are required to validate the approach for comprehensive global circulation models. Copyright q 2006 John Wiley & Sons, Ltd.
Why Do Central Banks Exist

This article describes in some detail the properties of free market money and banking so as to contrast state-controlled central bank money and banking. It examines seven steps that government takes to replace the free market with central banking as it creates a banking system cartel. A number of myths surrounding central banking are spelled out and criticized, leading to an answer to the question of why central banks really exist. The article strongly opposes the conventional wisdom surrounding both central banks and the role of economists in government actions.
RNA-Based Detection Does not Accurately Enumerate Living Escherichia coli O157:H7 Cells on Plants

The capacity to distinguish between living and dead cells is an important, but often unrealized, attribute of rapid detection methods for foodborne pathogens. In this study, the numbers of enterohemorrhagic Escherichia coli O157:H7 after inoculation onto Romaine lettuce plants and on plastic (abiotic) surfaces were measured over time by culturing, and quantitative PCR (qPCR), propidium monoazide (PMA)-qPCR, and reverse transcriptase (RT)-qPCR targeting E. coli O157:H7 gapA, rfbE, eae, and lpfA genes and gene transcripts. On Romaine lettuce plants incubated at low relative humidity, E. coli O157:H7 cell numbers declined 107-fold within 96 h according to culture-based assessments. In contrast, there were no reductions in E. coli levels according to qPCR and only 100- and 1000-fold lower numbers per leaf by RT-qPCR and PMA-qPCR, respectively. Similar results were obtained upon exposure of E. coli O157:H7 to desiccation conditions on a sterile plastic surface. Subsequent investigation of mixtures of living and dead E. coli O157:H7 cells strongly indicated that PMA-qPCR detection was subject to false-positive enumerations of viable targets when in the presence of 100-fold higher numbers of dead cells. RT-qPCR measurements of killed E. coli O157:H7 as well as for RNaseA-treated E. coli RNA confirmed that transcripts from dead cells and highly degraded RNA were also amplified by RT-qPCR. These findings show that neither PMA-qPCR nor RT-qPCR provide accurate estimates of bacterial viability in environments where growth and survival is limited.
The Black Movement and Women's Liberation

(1970). The Black Movement and Women's Liberation. The Black Scholar: Vol. 1, Black Revolution, pp. 36-42.