cssi/SciSciGPT-SciSciNet huggingface dataset:
Humidified Gas Stream Separations at High Temperatures Using Matrimid 5218

Most industrially relevant high temperature gas separations (≥150°C) of either carbon dioxide (flue gas) or hydrogen (syn-gas) must be performed in the presence of water vapor. At ambient temperatures, water vapor can permeate easily through most polymeric membranes and can influence the permeation of other gases through interaction with the polymer, such as swelling and clustering. At higher temperatures, water vapor can be destructive to polymer membranes by changing the polymer structure that can result in diminished gas separation performance. Little data has been reported on the influence of water vapor in gas separations at >100°C because most polymers are not stable at temperature. Many high performance (HP) polymers are able to endure high temperatures and aggressive chemical conditions. For example, polyimides are promising HP polymers that effectively separate permanent gases at temperatures higher than 150°C under dry conditions. In this report, the analysis of selected HP polymers in humidifie...
Parents as Models in Children's Cultural Development

(1986). Parents as Models in Children's Cultural Development. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 60, No. 2, pp. 72-75.
Anesthesia advances during the Civil War.

The advent of general inhalation anesthesia, in the form of ether (1846) or chloroform (1847), revolutionized medicine for surgeons and patients. Its efficacy in wartime was quickly tested in the Civil War, establishing that painless surgery on the battlefield might be possible (Fig. 1). Despite prior, widespread use of ether by American doctors, chloroform became the anesthetic agent of choice by Union and Confederate Army surgeons, due primarily to its nonflammability and the “rapidity of its effects [. . .] and from the small quantity required.” Army Surgeon B. B. Breed, United States Volunteers wrote that while he personally preferred ether, “on the field of battle [. . .] chloroform is the safe and preferable agent.” As the war progressed, authors of the “Medical and Surgical History of the War of Rebellion (MSHWR)” determined that gathering statistics on the use of anesthesia was “impracticable.” Indeed it may be the only instances in the creation of “MSHWR’s” six volumes that the gathering of data was considered unfeasible—a notable distinction in its own right. They determined that chloroform was used at least 80,000 times and individual testimonies from field surgeons
The rgg Gene of Streptococcus pyogenes NZ131 Positively Influences Extracellular SPE B Production

Streptococcus pyogenes produces several extracellular proteins, including streptococcal erythrogenic toxin B (SPE B), also known as streptococcal pyrogenic exotoxin B and streptococcal proteinase. Several reports suggest that SPE B contributes to the virulence associated with S. pyogenes; however, little is known about its regulation. Nucleotide sequence data revealed the presence, upstream of the speB gene, of a gene, designated rgg, that was predicted to encode a polypeptide similar to previously described positive regulatory factors. The putative Rgg polypeptide of S. pyogenes NZ131 consisted of 280 amino acids and had a predicted molecular weight of 33,246. To assess the potential role of Rgg in the production of SPE B, the rgg gene was insertionally inactivated in S. pyogenes NZ131, which resulted in markedly decreased SPE B production, as determined both by immunoblotting and caseinolytic activity on agar plates. However, the production of other extracellular products, including streptolysin O, streptokinase, and DNase, was not affected. Complementation of the rgg mutant with an intact rgg gene copy in S. pyogenes NZ131 could restore SPE B production and confirmed that the rgg gene product is involved in the production of SPE B.
Polydicyclopentadiene aerogels grafted with PMMA: II. Nanoscopic characterization and origin of macroscopic deformation

Polydicyclopentadiene (pDCPD) is a polymer of emerging technological significance from separations to armor. It is a paradigm of ring opening metathesis polymerization (ROMP) and should be an ideal candidate for strong nanoporous solids (aerogels), however, excessive swelling of pDCPD wet-gels in toluene (up to 200% v/v), followed by de-swelling and severe deformation in acetone, renders the resulting aerogels unusable. With only 4–5% of the pendant cyclopentene double bonds of pDCPD engaged in crosslinking (see previous paper of this issue), introducing additional crosslinking with polymethylmethacrylate (PMMA) was deemed appropriate. Thus, even with an uptake of PMMA as low as 13% w/w, the resulting aerogels kept the shape and dimensions of their molds. Evidence though suggests (e.g., DSC) that PMMA remains a linear polymer, hence pDCPD/PMMA networks resist deformation, not because of molecular-level crosslinking, but due to a synergism related to the nano-topology of the two components. SEM and N2 sorption on dry aerogels show that macroscopic deformation of wet-gels is accompanied by coalescence of nanoparticles. Small angle X-ray scattering (SAXS) shows that both deformed (pDCPD) and non-deformed (pDCPD/PMMA) aerogels consist of same-size primary particles (8–9 nm radius) that form non-mass-fractal secondary particles (21–27 nm radius). On the other hand, rheology shows that the pDCPD gel network is formed by mass fractal aggregates (Df ∼ 2.4). Putting this information together, it is concluded that the pDCPD network is formed by aggregates of secondary particles. It is suggested that particles coalescence is driven by non-covalent interactions that squeeze deformable secondary particles of one fractal assembly inside the empty space of another. As supported by skeletal density considerations, PMMA fills the space between primary particles; thus, secondary particles become rigid and can no longer squeeze past one another into the empty space of their higher fractal aggregates.
AKAP-Mediated Targeting of Protein Kinase A Regulates Contractility in Cardiac Myocytes

Compartmentalization of cAMP-dependent protein kinase A (PKA) by A-kinase anchoring proteins (AKAPs) targets PKA to distinct subcellular locations in many cell types. However, the question of whether AKAP-mediated PKA anchoring in the heart regulates cardiac contractile function has not been addressed. We disrupted AKAP-mediated PKA anchoring in cardiac myocytes by introducing, via adenovirus-mediated gene transfer, Ht31, a peptide that binds the PKA regulatory subunit type II (RII) with high affinity. This peptide competes with endogenous AKAPs for RII binding. Ht31P (a proline-substituted derivative), which does not bind RII, was used as a negative control. We then investigated the effects of Ht31 expression on RII distribution, Ca(2+) cycling, cell shortening, and PKA-dependent substrate phosphorylation. By confocal microscopy, we showed redistribution of RII from the perinuclear region and from periodic transverse striations in Ht31P-expressing cells to a diffuse cytosolic localization in Ht31-expressing cells. In the presence of 10 nmol/L isoproterenol, Ht31-expressing myocytes displayed an increased rate and amplitude of cell shortening and relaxation compared with control cells (uninfected and Ht31P-expressing myocytes); with isoproterenol stimulation we observed decreased time to 90% decline in Ca(2+) but no significant difference between Ht31-expressing and control cells in the rate of Ca(2+) cycling or amplitude of the Ca(2+) transient. The increase in PKA-dependent phosphorylation of troponin I and myosin binding protein C on isoproterenol stimulation was significantly reduced in Ht31-expressing cells compared with controls. Our results demonstrate that, in response to beta-adrenergic stimulation, cardiomyocyte function and substrate phosphorylation by PKA is regulated by targeting of PKA by AKAPs.
Adenoviral Receptor Expression of Normal Bladder and Transitional Cell Carcinoma of the Bladder

Objective: The insertion of absent or underexpressed genes into cancer cells to alter their malignant phenotype is an important potential application of available gene therapy techn
Topological properties of least-squares error surfaces for adaptive IIR filters

In this paper, a new framework for understanding the performance of adaptive IIR filters is proposed and shown to enhance the understanding of filter stability during adaptation in time- varying data environments. This new understanding arises from considering the error surface as defined by the data, rather than the statistics of the data, in a manner analogous to that used to develop recursive least squares (RLS) FIR adaptive filters. The stability of the filter is shown to be dependent on the problem formulation. Defining the time-varying error surface using frequency domain, rather than time domain, methods is shown to result in substantially better stability structure in the performance surface.
Automated classification of signals with duration-dependent segments via class-specific features and Gibbs sampling

We study time series modelled as variable duration hidden Markov (VDHMM) segments. The observations within each segment can be statistically dependent and parameterized according to an unknown distribution. Gibbs sampling and class-specific (CLASP) feature methods, which are comfortable in high-dimensional and complex problems, are applied to the segmentation and, ultimately, the integrated classification of these segmented time series; that is, the segmentation is automatic, the segments are soft-classified according to the candidate VDHMM models, and a menu of VDHMM models themselves compete to claim the overall time series. Simulation results show their effectiveness, and, in particular, we highlight the benefits of incorporating the Markov structure of the segment types and the segment duration probability information. Techniques for estimation of the VDHMM models from training data are also given.
CD13 promotes mesenchymal stem cell-mediated regeneration of ischemic muscle

Mesenchymal stem cells (MSCs) are multipotent, tissue-resident cells that can facilitate tissue regeneration and thus show great promise as potential therapeutic agents. Functional MSCs have been isolated and characterized from a wide array of adult tissues and are universally identified by the shared expression of a core panel of MSCs markers. One of these markers is the multifunctional cell surface peptidase CD13 that has been shown to be expressed on human and murine MSCs from many tissues. To investigate whether this universal expression indicates a functional role for CD13 in MSC biology we isolated, expanded and characterized MSCs from bone marrow of wild type (WT) and CD13KO mice. Characterization of these cells demonstrated that both WT and CD13KO MSCs expressed the full complement of MSC markers (CD29, CD44, CD49e, CD105, Sca1), showed comparable proliferation rates and were capable of differentiating toward the adipogenic and osteogenic lineages. However, MSCs lacking CD13 were unable to differentiate into vascular cells, consistent with our previous characterization of CD13 as an angiogenic regulator. Compared to WT MSCs, adhesion and migration on various extracellular matrices of CD13KO MSCs were significantly impaired, which correlated with decreased phospho-FAK levels and cytoskeletal alterations. Crosslinking human MSCs with activating CD13 antibodies increased cell adhesion to endothelial monolayers and induced FAK activation in a time dependent manner. In agreement with these in vitro data, intramuscular injection of CD13KO MSCs in a model of severe ischemic limb injury resulted in significantly poorer perfusion, decreased ambulation, increased necrosis and impaired vascularization compared to those receiving WT MSCs. This study suggests that CD13 regulates FAK activation to promote MSC adhesion and migration, thus contributing to MSC-mediated tissue repair. CD13 may present a viable target to enhance the efficacy of mesenchymal stem cell therapies.
Screening for pancreatic neoplasia in high-risk individuals: an EUS-based approach

Abstract Background & Aims: Relatives of patients with pancreatic cancer and persons with certain inherited syndromes are at increased risk for developing pancreatic cancer. We prospectively evaluated the feasibility of screening for pancreatic neoplasia in high-risk individuals. Methods: Individuals from familial pancreatic cancer kindreds and a patient with Peutz-Jeghers syndrome underwent screening endoscopic ultrasound (EUS). If the EUS was abnormal, EUS-guided fine-needle aspiration, endoscopic retrograde cholangiopancreatography (ERCP), and spiral computed tomography (CT) were performed. Patients with abnormalities suggesting neoplasia had surgery. Results: Thirty-eight patients were studied; 31 (mean age, 58 yr; 42% men) from kindreds with ≥3 affected with pancreatic cancer; 6 from kindreds with 2 affected relatives, 1 was a patient with Peutz-Jeghers syndrome. None had symptoms referable to the pancreas or suggestive of malignancy. Six pancreatic masses were found by EUS: 1 invasive ductal adenocarcinoma, 1 benign intraductal papillary mucinous neoplasm, 2 serous cystadenomas, and 2 nonneoplastic masses. Hence, the diagnostic yield for detecting clinically significant pancreatic neoplasms was 5.3% (2 of 38). The 1 patient with pancreatic cancer was treated and still is alive and disease-free >5 years after surgery. EUS changes similar to those associated with chronic pancreatitis were found, which were more common in patients with a history of regular alcohol intake ( P = 0.02), but also occurred in patients who did not consume alcohol. Screening also led to a new diagnosis and treatment of symptomatic upper-gastrointestinal conditions in 18.4% of patients. Conclusions: EUS-based screening of asymptomatic high-risk individuals can detect prevalent resectable pancreatic neoplasia but false-positive diagnoses also occur.
Mechanisms, pathways, and dynamics of excited-state energy flow in self-assembled wheel-and-spoke light-harvesting architectures.

Static and time-resolved optical measurements are reported for two cyclic hexameric porphyrin arrays and their self-assembled complexes with guest chromophores. The hexameric hosts contain zinc porphyrins and 0 or 3 free base (Fb) porphyrins (denoted Zn6 or Zn3Fb3, respectively). The guests are a tripyridyl arene (TP) and a dipyridyl-substituted free base porphyrin (DPFb), each of which coordinates to zinc porphyrins of a host via pyridyl−zinc dative bonding. Each architecture is designed to have an overall gradient of excited-state energies that affords excitation funneling within the host and ultimately to the guest. Collectively, the studies delineate the various pathways, mechanisms, and rate constants of energy flow among the weakly coupled constituents of the host−guest complexes. The pathways include downhill unidirectional energy transfer between adjacent chromophores, bidirectional energy migration between identical chromophores, and energy transfer between nonadjacent chromophores. The energy tr...
Properties and potential of a polarization technique for the separation of the overlapping fluorescence and elastic scattering applied to algae in seawater

We present the results of recent experiments and analysis on the polarization discrimination technique developed by us to separate elastic reflectance and fluorescence components resulting from white light illumination of algae in seawater. The technique uses the polarized properties of elastically scattered light and unpolarized properties of fluorescence to separate the two. The approach was successfully applied to measurements on four types of algae of different sizes and shapes in the laboratory, with both polarized and unpolarized illumination sources. The procedure is shown to be effective for extraction of the chlorophyll fluorescence in the 685 nm region from reflectance of algae dominated by chlorophyll pigments with different angles of illumination for both polarized and unpolarized light sources, including sunlight. The results are compared with other methods for the estimation of chlorophyll concentrations, such as blue/green ratio, and the fluorescence line height above the baseline. We also report the results of experiments which examine the impact of surface roughness on the efficacy of the technique for measurements above the surface.
Sources of black-white earnings differences

An unmistakable fact of U.S. society is the disparity of incomes be- tween blacks and whites. At an aggregate level, the income of a typical black family is some 60% of that for a typical white family.’ Despite extensive research, it remains unclear what causes these differences. While race per se undoubtedly enters, it is clearly an oversimplification to label all differences simply as due to discrimination. The typical black and white workers differ in terms of schooling, experiences, job choices, residential location, and a myriad of other factors that might affect earn- ings. Knowledge of the quantitative importance of each of these possible sources of differences is essential whenever one considers policies that might be introduced to lessen the observed differences. This paper attempts to decompose the observed earnings differences between blacks and whites into more fundamental factors. These dif- ferences can, very generally, arise from a variety of underlying factors- including differences in the schooling and experience levels of individuals (the focus of much active governmental policy), differences in the “qual- ity” of schooling and experiences, differences in “general abilities” of the population, and differences in the rewards to these factors. The problem is, however, more complicated than this. The rewards to any specific factors represent market outcomes that aggregate the supplies of individual characteristics and the demands for these. The demands for specific factors may well vary across labor markets, implying that the rewards, say for given amounts of schooling, will also vary across labor markets. Thus, the specific distribution of individuals across labor markets will enter into any aggregate earnings comparisons.
Bounds on margin distributions in learning problems

Abstract Let (S, A ,P) be a probability space and let Pn be the empirical measure based on i.i.d. sample (X1,…,Xn) from P. Let F be a class of measurable real valued functions on (S, A ). For f∈ F , define Ff(t):=P{f⩽t} and Fn,f(t):=Pn{f⩽t}. Given γ∈(0,1], define en,γ(δ):=1/(n1−γ/2δγ). We show that if the L2(Pn)-entropy of the class F grows as e−α for some α∈(0,2), then, for all f∈ F and all δ∈(0, Δ n ), Δ n = O (n 1/2 ), F f ( δ c(σ) )⩽c(σ)[F n,f (δ)∨ 1 σ e n,γ (δ)] and F n,f ( δ c(σ) )⩽c(σ)[F f (δ)∨ 1 σ e n,γ (δ)], where γ= 2α 2+α and c(σ)↓1 as σ↓0 (the above inequalities hold for any fixed σ∈(0,1] with a high probability). Also, define δ n (γ;f):= sup {δ: F f (δ)⩽e n,γ (δ)} and δ n (γ;f):= sup {δ: F n,f (δ)⩽e n,γ (δ)}. Then for all γ> 2α 2+α δ n (γ;f) δ n (γ;f) →1 as n→∞ uniformly in F and with probability 1 (for γ= 2α 2+α the above ratio is bounded away from 0 and from ∞). The results are motivated by recent developments in machine learning, where they are used to bound the generalization error of learning algorithms. We also prove some more general results of similar nature, show the sharpness of the conditions and discuss the applications in learning theory.
Continuum Percolation Theory for Saturation Dependence of Air Permeability

Continuum percolation theory has recently been used to find the saturation, S , dependence of the hydraulic conductivity, K ( S ), of probabilistic fractal porous media. Analysis of K ( S ) in conjunction with solute diffusion revealed the presence of a critical volume fraction, θ t , for percolation in natural porous media. For moisture contents within a few percent of θ t , K ( S ) depends on the moisture content as a power of θ − θ t . At higher moisture contents, K ( S ) is determined through critical path analysis, which uses continuum percolation theory to find the dependence of a bottleneck (flow-limiting) pore radius on S . The physics near θ t is thus dominated by connectivity and tortuosity issues, but far from θ t by the variations in the radius of a bottleneck pore. Here it is demonstrated that the bottleneck pore radius for air permeability, k a , does not change as a function of saturation. Using the same scaling for the air permeability in the vicinity of the percolation of the air phase as proposed for the hydraulic conductivity in the vicinity of the percolation of the water phase yields results for k a in accordance with experimental data.
Evidence for cleavage of polymer chains by crack propagation

CRACK propagation in polymers is a topic of considerable importance to the technological application of these materials. In high-molecular-weight glassy polymers, crack propagation is normally assumed to require the breaking of covalent bonds in polymer chains that span the crack path, as opposed to chain slip and disentanglement. The fraction of such broken chains in a bulk sample would be very small, however, so that there is little direct evidence for this chain breakage1. Interfaces between immiscible polymers are often very weak, but can be strengthened by the presence of a diblock copolymer (a polymer in which each molecule consists of a block of one polymer bonded to a block of a different polymer) for which each of the two blocks is miscible with one of the homopolymers2. The diblock copolymer is thought to organize at the interface and so 'stitch' the homopolymers together. Here we show that crack propagation along the interface between the homopolymers involves breaking all the copolymer chains at a point in the region of the junction between the two blocks. Thus we demonstrate both that the block copolymer does indeed organize at the interface and that fracture involves the breaking of polymer chains. This information may suggest means by which the mechanical properties of polymer blends could be systematically improved.
New directions or not: USAID in Latin America.

Abstract In 1973 the US Congress passed a resolution directing the Agency for International Development (USAID) to provide its economic aid to the poorest populations in the poorest countries. This paper studies whether the congressional initiative has been satisfied in US bilateral economic aid allocations to Latin America. We compare aid given before and after 1973 to Latin American countries as a function of four independent variables: child mortality; political stability; imports from the United States; and GDP per capita. The dependent variable is the percentage of all USAID Latin American loans and grants given to each country. Our results suggest that USAID has not followed the congressional directive.
A foam ablation model for lost foam casting of aluminum

A model is developed for heat transfer, polymer vaporization, and gas diffusion at the interface between the advancing liquid metal and the receding foam pattern during mold filling in lost foam casting of aluminum. Most of the pattern interior decomposes by ablation, but the boundary cells decompose by a collapse mechanism, which creates an undercut in the pattern next to the coating. By regulating how much of the pattern coating is exposed to gas diffusion, the undercut controls the overall filling speed of the metal through the mold. Computed values for the foam decomposition energy from this model compare very well with experimental data on foam pyrolysis, and predicted filling speeds are consistent with observations in published experiments. In addition, the model explains several unusual observations about mold filling that until now have not been understood.
Electronic spectral shifts, reorganization energies, and local density augmentation of Coumarin 153 in supercritical solvents

Abstract Solvent reorganization energies and local densities of Coumarin 153 (C153) in supercritical C2H6, CO2, and CHF3 (Tc=5 K) are measured using fluorescence spectroscopy. Reorganization energies are 320±70 and 770±70 cm−1 in CO2 and CHF3, respectively – nearly independent of density (0.3≤ρ/ρc≤2.1). The spectral shifts imply similar effective local densities in all three solvents. These effective densities can exceed 3–5 times the bulk density. In CO2 and CHF3, the maximum density augmentation calculated from emission shifts is ∼20% greater than that calculated from excitation shifts. No such difference is found in C2H6.
Air-drying bio-based polyurethane dispersion from cardanol: Synthesis and characterization of coatings

Abstract Exploring bio-renewable materials to replace petroleum-based building blocks for advanced coatings has been a major thrust area for researchers for the development of eco-friendly and sustainable products. For the last few decades, there has been significant interest among coating researchers around the world to design water-based polyurethane dispersions (PUDs) that can be cured at ambient conditions. In the present work we synthesized auto-oxidizable PUDs based on cardanol as sustainable material that also provides self-crosslinking attribute to the PUDs. Such types of PUDs are expected to be suitable for water-based industrial protective primers. The cardanol-based intermediates and final products are characterized by FTIR spectroscopy for conformation of synthesis reaction and their structures. The dried films of the coatings, formulated using a suitable drier catalyst, exhibited improvement in mechanical properties and solvent resistance. The oxidative curing has also been investigated by FTIR and differential scanning calorimetry (DSC). The corrosion resistance properties of the coatings on steel substrate, as studied by using electrochemical impedance spectroscopy (EIS) technique also showed better performance for cross-linked films.
Regulating gene expression in zebrafish embryos using light-activated, negatively charged peptide nucleic acids.

We report the synthesis, characterization, and in vivo application of light-activated, negatively charged peptide nucleic acids (caged ncPNAs) for down-regulating gene expression during zebrafish embryonic development. The 18-mer ncPNAs were attached to a short complementary 2‘-OMe RNA sense strand (sRNA) via a heterobifunctional photocleavable linker (PL). Caged ncPNAs were designed to target chordin and bozozok mRNA. Modest UV irradiation cleaved the photoactive linker, which yielded the less stable ncPNA/sRNA duplex (ΔTm ∼ −20 °C for chordin and −41 °C for bozozok). These caged ncPNAs were microinjected into zebrafish (Danio rerio) embryos at the one- or two-cell stage. The conjugate was nontoxic, and most embryos showed no phenotypic response at 24 h post fertilization (24 hpf), which indicated low background activity. Embryos that were photoactivated at 2 or 3 hpf developed phenotypic abnormalities typical of embryos with loss of function of the chordin or bozozok gene. Phenotypic results were furthe...
Ideology and the History of Science

Antoine Destutt de Tracy, who coined the term "ideology," considered his new discipline a general science of our "intellectual faculties, their principal phenomena, and the more remarkable circumstances of their activities" (1801, p. 4). Convinced of the sensationalist epistemology of Locke and Condillac, Destutt de Tracy believed one could resolve all ideas into the sensations that produced them and thereby test their soundness. The sensationalist assumptions of his project led him to propose that "ideology is a part of zoology" (1801, p. 1), and he consequently paid close attention to the way physiological circumstance shaped and often misshaped ideas. Though Karl Marx appropriated this concept of ideology, he explored not physiological but cultural determinants. He concerned himself with the way material and economic conditions influenced ideas, especially when they produced a false consciousness of the supposed reality to which they referred. Marx believed his principles of analysis would allow him to distinguish sound ideas from those tainted by particular circumstance. The concept of ideology from its beginning has thus depended upon the presumption that some ideas can escape the kind of distortion from which others suffer. During our century, the concept of ideology has speciated. In the social sciences and humanities, it has come to be applied with a variety of different assumptions and meanings. 1 Historians and philosophers of science, however, have usually sustained the original presumption that a clear distinction can be made between true or at least 'rationally sound' and false ideas. Karl Popper, for instance, conceives ideology as a pseudo-scientific system like psychoanalysis or, for that matter, Marxism that pretends to science but essentially lacks the requisite rational methodology. For Popper, of course, the rational method of science, by which it can be distinguished from its ideological counterfeit, is falsificationism. The uncritical and stubborn adherence to a position, protecting it from confuting evidence by developing ad hoc hypotheses, clearly indicates an ideological conception. It is in this Viennese vein that Georges Canguilhem (1988), mentor of Foucault, defined a scientific ideology:
Use of Interference to Extinguish Reflection of Light from Glass

The phenomena of interference of light rays reflected from the two boundaries of a thin film cause the intensity ${I}_{R}$ of the resultant light to be greater or less than the intensity of the individual rays. The value of ${I}_{R}$ is determined by (a) the refractive index of the film, ${n}_{1}$, and the substance on which the film is deposited, ${n}_{g}$, (b) the thickness of the film, (c) the angle of incidence at which light strikes the film, (d) the wave-length of the light. The conditions necessary to obtain extinction of reflected light are described. In the case of monochromatic perpendicular light ${I}_{R}=0$ when ${n}_{1}={{n}_{g}}^{\frac{1}{2}}$ and the thickness $t$ is given by $t=\frac{0.25\ensuremath{\lambda}(2a+1)}{2}$ where $a$ is zero or an integer. The technique of building films which have the required values of ${n}_{1}$ and $t$ is described. The films are made by building up monomolecular layers, each layer consisting of 50 percent cadmium arachidate and 50 percent arachidic acid. The film is then soaked in alcohol which dissolves the arachidic acid and leaves a skeleton of cadmium arachidate. The refractive index of the skeleton is determined by the amount of arachidic acid which has been removed from the film. Since the interstices are of molecular size there is no appreciable scattering of the reflected light.
Abstract 2537: UVB irradiation induces nuclear translocation of TC-PTP in keratinocytes

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Ultraviolet B radiation (UVB) can cause DNA damage, induce gene mutations and modulate intracellular signal transduction contributing to the development of skin cancer. Signal transducer and activator of transcription 3 (Stat3) modulates various physiological functions, including apoptosis, cell cycle regulation, and tumor angiogenesis through regulation of gene expression, and its constitutive activation is associated with human epithelial cancers. Recent studies demonstrated that T-cell protein tyrosine phosphatase (TC-PTP) dephosphorylates activated Stat3 in keratinocytes after UVB irradiation. In the current work, we report that TC-PTP translocates from the cytosol to the nucleus and dephosphorylates Stat3 following UVB irradiation in keratinocytes. Western blot analysis showed that TC-PTP mainly localized in the cytoplasm of keratinocytes and translocated from cytoplasm to nucleus upon UVB irradiation. Immunofluorescence analysis of the exogenous expression of TC-PTP confirmed its nuclear translocation, and showed that nuclear translocation of TC-PTP occurs independently of its phosphatase activity. Nuclear translocation of TC-PTP was increased with increased dose of UVB exposure. Dephosphorylation of Stat3 by TC-PTP was enhanced after UVB irradiation of cultured keratinocytes with nuclear accumulation of TC-PTP. Knockdown of TC-PTP with siRNA suppressed dephoshorylation of Stat3 and enhanced cell viability in response to UVB irradiation. UVB irradiation also induced expression of 14-3-3α, a protein that has been shown to be involved in the transport of proteins. Further studies revealed that UVB-induced nuclear translocation of TC-PTP was effectively inhibited by knockdown of 14-3-3α, suggesting 14-3-3α is involved in nuclear import of TC-PTP. These results indicate that TC-PTP plays an important role as a regulator of Stat3 signaling in keratinocytes upon UVB irradiation. Nuclear translocation of TC-PTP is regulated by a 14-3-3α-dependent signaling pathway, resulting in the rapid dephosphorylation of activated Stat3 in the nucleus. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2537. doi:1538-7445.AM2012-2537
The Homunculi approach to social and emotional wellbeing: a flexible CBT programme for young people on the autism spectrum or with emotional and behavioural difficulties

This A4 size book describes a 10 week programme for individuals or groups, aged seven upwards, aimed at building social and emotional resilience for those with Autism Spectrum Conditions (ASC) and ...
Direct Visualization of Tropomyosin Isoform Binding to F-Actin

There are more than forty different tropomyosin isoforms in mammalian cells produced via alternative splicing from four separate genes. These isoforms have varying expression levels in different cell types and are targeted to specific regions of cells. In turn, the proper regulation of actin-binding protein interactions relies on the ability of different tropomyosin isoforms, each with its own unique actin-binding properties, to target a particular subset of actin filaments and define filament functions. Despite the large number of studies that have investigated the various cellular roles played by tropomyosin, the mechanism of differential tropomyosin binding to actin filaments remains uncertain.In this work, we used TIRF microscopy to monitor Alexa-532-labeled tropomyosin binding to actin. We found that random, weak monomer binding leads to the formation of "nucleation sites" with enhanced affinity for the actin filament-a process most likely dependent on the tropomyosin end-to-end interactions. Stepwise changes in fluorescence intensity observed indicate that three tropomyosin molecules are required to form a stable nucleation site. From these sites, subsequent chain elongation is rapid and appears to depend on the strength of such end-to-end "tropomyosin linkages." This mechanism, which is strongly dependent on polymer formation rather than initial monomer binding onto the actin filament, suggests that tropomyosin isoform sorting may be intrinsic to the end-to-end linkage sites. A mixture of Tm2-Cy3 and Tm5NM1-Cy5.5 labeled tropomyosins was shown to segregate on F-actin and form distinct "patches" along actin filaments. We hypothesize that the C-terminal region of tropomyosin, which is highly variable among tropomyosin isoforms, is the primary determinant in distinguishing among different isoforms.
Mammalian DNA methyltransferase 1: inspiration for new directions.

The role of DNA methyltransferase 1, DNMT1, in human cancer cells has recently been contested. In this setting, DNMT1’s function as the sole maintenance methyltransferase was based on the assumption that its biological activity is identical to the mouse homologue. However, the application of recent technological advances, including gene targeting and siRNA mediated ablation studies, has cast doubt on this presumed role. Here, we attempt to shed light on these new data within the context of previous experiments.
Potentiation of the excitatory action of NMDA in ventrolateral periaqueductal gray by the μ-opioid receptor agonist, DAMGO

Several lines of evidence have suggested that μ-opioids, generally regarded as inhibitory, also have effects that stimulate neural activity. To look for possible excitatory opioid action in the rat periaqueductal gray (PAG), we first re-examined data from a previous study and found that met-enkephalin could evoke a delayed, sluggish excitation, suggestive of modulation by the opioid on the action of certain excitants. This observation, coupled with other studies that show μ-opioids can modulate NMDA receptor activation, prompted us to perform extracellular recording of the responses of single ventrolateral PAG (vlPAG) neurons in brain slices to DAMGO, a μ-opioid, and to NMDA. When applied alone, DAMGO at nM concentrations, like met-enkephalin, often evoked the delayed excitation and occasionally an inhibition. When applied after a brief exposure to NMDA, DAMGO at doses as low as 0.1 nM potentiated the excitation produced by a subsequent pulse of NMDA. This occurred, depending on cell type, in 23–100% of vlPAG neurons. The potentiating action of DAMGO was blocked by naloxone, suggesting it was mediated by μ-opioid receptors. Characterization of these μ-opioid actions revealed that the potentiation and the delayed excitation, unlike the inhibition, was not blocked by another opioid antagonist, nalmefene, nor by an inhibitor of the G protein of the Gi class, N-ethylmaleimide. Moreover, the potentiating action was distinct from the inhibition in that it was: (a) enhanced by repeated opioid applications, (b) exhibited low effective doses, (c) had a long time course (minutes to develop and last tens of minutes) and (d) was present in distinct though overlapping cell populations. These data reveal an unconventional action of opioids in PAG neurons, that is, a potentiation of excitation produced by NMDA. This effect appeared mechanistically distinct from opioid inhibition or disinhibition and may be related to established examples of direct opioid excitation. These observations may help understanding behaviorally important mechanisms linked to acute and chronic opioid functions in the vlPAG.
Effects of microstructure on the radiation stability of amorphous semiconductors

Abstract The influence of phase separated and crystalline regions on the fast neutron and X-ray damage thresholds of germanium chalcogenides and vanadia-phosphate semiconducting glasses has been established. Damage thresholds are shown to be a function of volume fraction and size of heterogeneities, and the bond energies of the glass. A theoretical model interpreting structure-dependent radiation damage is presented based on heterogeneous semiconductor theory and the destruction of interfacial Schottky barriers. Applications of the results to predicting the radiation sensitivity of amorphous semiconductor devices are suggested.
New Approach for Calculating Position Domain Integrity Risk for Cycle Resolution in Carrier Phase Navigation Systems

A new theoretical approach is described to quantify position-domain integrity risk for cycle ambiguity resolution problems in satellite-based navigation systems. It is typically conservatively assumed that all incorrectly fixed cycle ambiguities cause hazardously large position errors. While simple and practical, this conservative assumption can unnecessarily limit navigation availability for applications with stringent requirements for accuracy and integrity. In response, a new method for calculating the integrity risk for carrier phase navigation algorithms is developed. In this method we evaluate the impact of incorrect fixes in the position domain and define tight upper bounds on the resulting navigation integrity risk. Furthermore, a mechanism to implement this method with partially-fixed cycle ambiguity vectors is also derived. The improvement in navigation availability using the new method is quantified through covariance analysis performed over a range of error model parameters.
Lateral equilibrium of asymmetrical swept wings - Aileron control vs geometric twist

A static aeroelastic phenomenon unique to an aircraft with asymmetrically swept wings is discussed. A simple formula is derived from the analysis of a highly idealized model. The validity of this formula is examined through the use of a more sophisticated numerical analysis. Among the results of this analysis are the following: aileron settings of a few degrees are sufficient to trim such aircraft in roll-for-g-flight; the use of built-in twist in the form of initial negative dihedral provides an efficient alternative to aileron trim; if the wing is elastically tailored in a proper fashion, it may be possible to design a wing whose elastic deformation under airloads provides a form of self-trim in roll at the cruise q of the aircraft.
The production of 11C by the interaction of 375 MeV/amu Ne10+ ions with carbon☆

Abstract We have measured the reaction cross section for production of 11 C from 12 C in a polystyrene target with incident 375 MeV/amu Ne 10+ ions at the Lawrence Berkeley Laboratory's Bevalac. We used a broad beam irradiation, and determined both beam profile and absolute particle fluence with LiF thermoluminescent dosimeters, which had been calibrated by track counting in nuclear emulsions; the induced target activity was measured with a NaI(Tl) crystal, γ-ray spectrometer. The reaction cross section was (75±7) mb.
The effects of dipolar cross correlation on 13C methyl-carbon T1, T2, and NOE measurements in macromolecules

Abstract The effects of dipolar cross correlation on 13 C T 1 , T 2 , and NOE values are calculated for methyl groups attached to macromolecules. Using the Woessner model to describe methyl-group internal dynamics, it is found that for macromolecules with tumbling times between 5 and 20 ns and fast internal methyl rotation characterized by a correlation time between 15 and 65 ps, the recovery of longitudinal magnetization differs by less than 10% from that of the case with no cross correlation. Therefore for a large range of values of τ m and τ e , cross-correlation effects on longitudinal relaxation are small, despite the fact that reorientation is highly anisotropic. In contrast, for 13 C spin-spin relaxation the effects of dipolar cross correlation are significant for all values of τ m and τ e in the range examined (2 ns τ m τ e 3 spin system attached to a macromolecule. The effect of cross correlation is calculated to change NOE values by no more than 6–7% in the range examined. The influence of neighboring 1 H spins on 13 C relaxation is assessed by including random-field effects in the calculations. While the effects of cross correlation are attenuated, 13 C longitudinal and transverse relaxation rates can, under certain conditions, still be substantially different from rates obtained in the absence of cross correlation. Although a quantitative description of cross-correlation effects on 13 C relaxation depends on the details of methyl-group internal dynamics, the results derived here using the Woessner model are qualitatively the same as results obtained for different descriptions of the methyl-carbon internal motions.
STEM literacy and textbook biases in K-12

Textbooks are a common source of science information in K-12 science education. Science literacy is a major challenge of students in K-12 and this dramatically affects students' achievement. Biases in textbooks negatively influence students' interest and achievement in science and engineering. This study explores types of biases in K-12 science texts. These biases primarily relate to gender, race and ethnicity. Textbook biases negatively affect students' views of science as a field, as a career and as a college major. Achievement may also be affected by such biases. Accordingly, this research study explores the biases in K-12 science textbooks. The textbooks were analyzed using a multidimensional rubric and accompanying scoring checklist. Results of these analyses revealed dramatic biases in textbooks particularly for early elementary and high school texts. Both print and photographic biases were noted in the textbooks. In particular, the books that focused on biological sciences were found to contain significant biases especially related to gender. These biases may influence how students feel about careers in science, technology, engineering and mathematics (STEM) areas and therefore may impact future workforces in STEM fields.
High-temperature diffusion barriers for protective coatings

Abstract An effective diffusion barrier between the superalloy and aluminide coating would reduce coating degradation by lowering the rate of Al loss to the substrate by interdiffusion, and by inhibiting diffusion of substrate elements (such as Cr, Re, Ta, W) into the coating, which degrade its corrosion and oxidation resistance. In this preliminary study, sputtered Hf–Ni and Hf–Pt were evaluated as potential high-temperature diffusion barrier layers beneath NiAl or NiPtAl coatings. A Ni 3 Hf-type layer formed during aluminizing of Ni–Hf thin films, and appeared to result in reduced β-NiAl depletion during oxidation testing at 1150 °C. Some Hf-containing simple aluminide coatings also showed very good oxidation resistance. However, the Ni–Hf phase disrupted coating microstructure and displayed limited high-temperature stability. Heat treatment of Hf and Pt thin films formed a compound similar to HfPt 3 -type, which subsequently dissolved during aluminizing.
Distribution of molecular aggregation by analysis of fluctuation moments.

Abstract The fluorescence from an open volume of a solution of fluorescent molecules fluctuates as the molecules randomly diffuse into and out of the volume. The distribution of degrees of aggregation or polymerization of the fluorescent molecules can be characterized without perturbing the system by measuring either the moments or the amplitude distribution of these fluctuations. We present an experimental verification of this approach applied to simple model systems consisting of solutions of fluorescent particles of well-defined size. We have also characterized the response of the photon-detection device (typically a photomultiplier), which is essential to the analysis of the fluorescence fluctuations, and have compared two methods for determining shot-noise contributions.
Insect hemolymph factor promotes muscle histolysis in solenopsis

Hemolymph was collected from both normal (virgin) females (control hemolymph) and artificially inseminated females (experimental hemolymph) of Solenopsis, ssp., the imported fire ant (primarily S. invicta and S. geminata). When the control hemolymph was injected into normal females, breakdown of the thoracic flight musculature was not seen 24 hr postinjection. In contrast, when the experimental hemolymph was injected into normal females, flight muscle histolysis was marked 24 hr postinjection. When the experimental hemolymph was heated to 70 degrees C prior to injection into normal females, subsequent flight muscle breakdown was not seen. The injection of freshly collected semen into normal females produced no effect on flight muscle structure. Also, the injection of the experimental hemolymph into normal, alate males produced no muscle histolysis. These observations suggest that the hemolymph from inseminated females contains a factor (or factors) that induces the specific breakdown and subsequent dissolution of the complex thoracic flight musculature. Other thoracic muscles (leg muscles, intersegmental muscles, etc.) are not affected. Based on observations made in both insect muscles as well as vertebrate skeletal muscles, it is suggested that such a hemolymph factor may act by disrupting the structural integrity of muscle cell membranes, resulting in significant changes in membrane permeability, especially with regard to calcium ions.
Thermal-timing instability in neutron stars

A thermal instability can occur in neutron stars, in which a significant burst of heat is generated in a short period of time. Accompanying this heat pulse is a change in the pulse repitition rate of the pulsar. A perturbation analysis of a simple model shows that the instability becomes easier to trigger as the star's initial temperature is reduced, and that once started it can grow very rapidly. The resulting time evolution of the pulsar angular velocity may resemble a period jump.