cssi/SciSciGPT-SciSciNet huggingface dataset:
Solidification/stabilization of phenolic waste with cementitious and polymeric materials☆

Abstract Methods of handling organic wastes more safely and decreasing the degree of hazard of disposed organic wastes are becoming critical elements in any hazardous waste management planning. In this study the potential of a thermosetting polyester polymer to solidify/stabiIize phenol, a primary constituent in many organic hazardous wastes and with a very low allowable level in drinking water, was investigated. The performance of rapid-setting high-strength polyester polymer in immobilizing 0.5 percent and 2 percent phenol has been studied in detail and compared to that of Type I portland cement. The effect of phenol concentrations on setting and microstructure of the polyester polymer and cement have been investigated. Phenol inhibits the setting of polyester polymer and cement and also produces large voids in the cement matrix. The phenol leachability and compressive and tensile properties were studied with curing time up to 30 days. Most of the polyester polymer solidified phenol specimens showed no measurable amount of phenol in the leachate after the extraction procedure test. The phenol recovery from cement matrix is very much dependent on curing time and initial phenol content. The compressive and tensile strengths of solidified waste reduces with increasing phenol content. The polyester polymer is very effective in rapidly solidifying/stabilizing phenol and the solidified waste has the potential to be used in construction applications.
Matrix Stiffness Corresponding to Strictured Bowel Induces a Fibrogenic Response in Human Colonic Fibroblasts

BACKGROUND Crohn's disease is characterized by repeated cycles of inflammation and mucosal healing which ultimately progress to intestinal fibrosis. This inexorable progression toward fibrosis suggests that fibrosis becomes inflammation-independent and auto-propagative. We hypothesized that matrix stiffness regulates this auto-propagation of intestinal fibrosis. METHODS The stiffness of fresh ex vivo samples from normal human small intestine, Crohn's disease strictures, and the unaffected margin were measured with a microelastometer. Normal human colonic fibroblasts were cultured on physiologically normal or pathologically stiff matrices corresponding to the physiological stiffness of normal or fibrotic bowel. Cellular response was assayed for changes in cell morphology, α-smooth muscle actin staining, and gene expression. RESULTS Microelastometer measurements revealed a significant increase in colonic tissue stiffness between normal human colon and Crohn's strictures and between the stricture and adjacent tissue margin. In Ccd-18co cells grown on stiff matrices corresponding to Crohn's strictures, cellular proliferation increased. Pathologic stiffness induced a marked change in cell morphology and increased α-smooth muscle actin protein expression. Growth on a stiff matrix induced fibrogenic gene expression, decreased matrix metalloproteinase, and proinflammatory gene expression and was associated with nuclear localization of the transcriptional cofactor MRTF-A. CONCLUSIONS Matrix stiffness, representative of the pathologic stiffness of Crohn's strictures, activates human colonic fibroblasts to a fibrogenic phenotype. Matrix stiffness affects multiple pathways, suggesting that the mechanical properties of the cellular environment are critical to fibroblast function and may contribute to auto-propagation of intestinal fibrosis in the absence of inflammation, thereby contributing to the intractable intestinal fibrosis characteristic of Crohn's disease.
Stability of stage-structured population models

In order to model populations which go through distinct stages, such as laboratory insect populations it is necessary to take the age structure of the population into account. The oscillations which have frequently been observed in the sizes of such populations cannot be explained by a model which ignores the effects of age structure. While it is feasible to use a fully age-structured model of McKendrickkvon Foerster type [3] or an analogous size-structured model [4], it is generally impossible to derive qualitative information about the behavior of solutions of such models. Accordingly, models have been proposed which subdivide the lifetime of an individual into two stages (larvae and adults), with different dynamics in each stage. Such models may be formulated as systems of differentialdifference equations, and several different types of systems of differentialdifference equations to model different types of larval competition have been proposed in [S]. Our purpose is to analyze the stability properties of the various models proposed in [S], using the standard method of determining equilibria, linearizing about an equilibrium, and locating the roots of the corresponding characteristic equation. By an equilibrium of a system of differential-difference equations we mean simply a constant solution; thus equilibria are found by setting the right side of each equation equal to zero (assuming that each equation of the system has been solved for the derivatives of the unknown functions). In cases where every constant is a solution of one of the equations in a system, it is necessary to replace that equation by an integrated form which incorporates the initial data in order to solve for equilibria. The linearization of a system about an equilibrium is obtained by using the deviations of the unknown functions from equilibrium as new variables, expanding by Taylor’s theorem, and retaining only the linear terms. The
Short communication: Effects of increasing protein and energy in the milk replacer with or without direct-fed microbial supplementation on growth and performance of preweaned Holstein calves

Abstract Forty-four Holstein calves were fed a direct-fed microbial (DFM) and 1 of 2 milk replacers to evaluate calf performance and growth. Treatments were (1) a control milk replacer [22:20; 22% crude protein (CP) and 20% fat], (2) an accelerated milk replacer (27:10; 27% CP and 10% fat), (3) the control milk replacer with added DFM (22:20+D), and (4) the accelerated milk replacer with added DFM (27:10+D). Dry matter intake, rectal temperatures, respiration scores and rates, and fecal scores were collected daily. Body weight, hip and withers height, heart girth, blood, and rumen fluid samples were collected weekly. Effects of treatment, sex, week, and their interactions were analyzed. Calves fed an accelerated milk replacer, regardless of DFM supplementation, consumed more CP and metabolizable energy in the milk replacer. No treatment differences were found for starter intake or intake of neutral detergent fiber or acid detergent fiber in the starter. Calves fed the accelerated milk replacer had greater preweaning and weaning body weight compared with calves fed the control milk replacer. Average daily gain was greater during the preweaning period for calves fed the accelerated milk replacer, but the same pattern did not hold true during the postweaning period. Feed efficiency did not differ among treatments. Hip height tended to be and withers height and heart girth were greater at weaning for calves fed the accelerated milk replacer compared with calves fed the control milk replacer. Fecal scores were greatest in calves fed DFM. Overall acetate, propionate, butyrate, and n -valerate concentrations were lower in calves fed the accelerated milk replacer, but DFM did not have an effect. Rumen pH was not different. Blood metabolites were unaffected by DFM supplementation, but calves fed the accelerated milk replacer had increased partial pressure of CO 2 , bicarbonate, and total bicarbonate in the blood. Direct-fed microbial supplementation did not appear to benefit the calf in this trial
Energy harvesting eel

Abstract The current study examines the feasibility of placing a piezoelectric membrane or “eel” in the wake of a bluff body and using the von Karman vortex street forming behind the bluff body to induce oscillations in the membrane. The oscillations result in a capacitive buildup in the membrane that provides a voltage source that can be used, for example, to trickle-charge a battery in a remote location. The aim of the hydrodynamic testing is to maximize the strain energy and mechanical power by coupling the unsteady flow field with the vibration of the membrane. The requirement of optimal coupling is best defined as a resonance condition where the membrane has a negligible damping effect on the original von Karman vortex street.
Complementation of M Gene Mutants of Vesicular Stomatitis Virus by Plasmid-Derived M Protein Converts Spherical Extracellular Particles into Native Bullet Shapes

Abstract The matrix (M) protein of vesicular stomatitis virus (VSV) binds the nucleocapsid to the cytoplasmic surface of the host plasma membrane during virus assembly by budding. It also condenses the nucleocapsid into a tightly coiled nucleocapsid–M protein complex that appears to give the virion its bullet-like shape. As described here, temperature-sensitive (ts) M mutants produced two classes of membrane-containing extracellular particles at the nonpermissive temperature. These could be distinguished by sedimentation in sucrose gradients and by electron microscopy. One class contained nucleocapsids and envelope glycoprotein, but very little M protein. The other class was devoid of nucleocapsids. Most of these particles were spherical or pleiomorphic in shape as determined by electron microscopy. Expression of wild-type (wt) M protein from plasmid DNA using the vaccinia/T7 virus system did not enhance the incorporation of nucleocapsids into extracellular particles from cells coinfected with the ts M mutants but did enhance the incorporation of M protein into these particles. Electron microscopy showed that wt M protein served to impart the bullet-like shape typical of VSV virions to what would otherwise be spherical or pleiomorphic virus-like particles. These data suggest that there are two distinct processes in VSV envelope biogenesis. One process involves envelopment of the nucleocapsid and can be accomplished by the ts M mutants at the nonpermissive temperature, albeit at a low level compared to wt VSV. The other process involves conversion of virion components into the bullet-like shape and requires a function provided by wt M protein.
All-Electron Hybrid Density Functional Calculations on UFn and UCln (n = 1−6)

We calculate the bond dissociation energies of the series UFn and UCln (n = 1-6) using the all-electron third-order Douglas-Kroll-Hess approximation in combination with hybrid density functionals. The spin-orbit (SO) operator is included self-consistently using the nuclear-only SO and the screened-nuclear SO approximations. Results are in very good agreement with experimental values, with the exception of the smallest molecules of each series, UF and UCl. By shifting the one-electron orbital energies of UF6 and UCl6 to match the HOMO level with the ΔSCF calculated value of the first ionization energy, we are able to reproduce the main features of the photoelectron spectrum of these two molecules.
Hydroxylated sterols and the human fetal adrenal

The conversion by isolated human fetal adrenal cells (24 wks gestation) of 25-OH-cholesterol (25-OH), 22S-OH-cholesterol (22S). 17,20-diOH-cholesterol(17,20) and 17-OH-pregnenolone(17-OH) into C21 and C19 steroids was studied.In additior the effects on the levels of free cholesterol (Chol) were determined. Substrates and products were estimated by capillary GC. Intracellular ATP was used as a viability criterion. Results: Production in μg/7×105 cells/2hrs DHEA=dehydroepiandrosterone; preg=pregnenolone The results suggest that these sterols not only act as precursors, but are able to stimulate steroid production by altering cellular metabolism.
Effects of intratracheal installation of dactinomycin on pulmonary edema and phosphatase activity of the lung lavage fluid in rats

Abstract Intratracheal (i.t.) administration of protein synthesis inhibitors produced pulmunary edema. O course inhibitors studied, dactinomycin (act. D) was the most potent. Severity of lung damage due to act. D was dose- and almost age-related. Maximal intensity of pulmunary edema was reached on the 3rd day following administration and relained constant for 14 days. Histopathological studies revealed confluent edema of the entire lung. Pretreatment with act. D induced tolerance to an ID 100 edematogenic dose of thiourea. The effect of i.t. instillation of act. D appear to be localized in the pulmonary tissue. Lung lavage fluid collected fromn drug-treated rats had higher acid and alkaline phosphatase activities, higher protein content and more leukocyte infiltration than that of control.
Sestrin2 Protein Positively Regulates AKT Enzyme Signaling and Survival in Human Squamous Cell Carcinoma and Melanoma Cells

Skin cancer is the most common cancer in the United States and is mainly caused by environmental UV radiation. Reducing skin cancer incidence is becoming an urgent issue. The stress-inducible protein Sestrin2 (Sesn2) plays an important role in maintaining redox and metabolic homeostasis and their related pathologies. However, the role of Sesn2 in cancer remains unclear. Here we show that UVB radiation induces Sesn2 expression in normal human keratinocytes, mouse skin, normal human melanocytes, and melanoma cells. In addition, Sesn2 promotes AKT activation through a PTEN-dependent mechanism. Sesn2 deletion or knockdown sensitizes squamous cell carcinoma (SCC) cells to 5-fluorouracil-induced apoptosis and melanoma cells to UVB- and vemurafenib-induced apoptosis. In mice Sesn2 knockdown suppresses tumor growth from injected human SCC and melanoma cells. Last, as compared with normal skin, Sesn2 is up-regulated in both human skin SCC and melanoma. Our findings demonstrate that Sesn2 promotes AKT activation and survival in response to UVB stress and chemotherapeutics and suggest that Sesn2 is oncogenic in skin SCC and melanoma.
A Mitochondrial Mystery, Solved

The three-carbon molecule pyruvate is a metabolic intermediate and a central hub for cellular energy metabolism. It lies at the junction of aerobic and anaerobic metabolism and is the precursor for biosynthetic pathways including glucose, lipid, and amino acid syntheses. Given the ubiquitous role of pyruvate in cellular bioenergetics (see the figure), its subcellular localization plays a critical role in its fate. The final product of pyruvate metabolism is fundamentally altered once it enters the mitochondrion. As such, the identity of the protein that transports pyruvate from the cytoplasm into mitochondria has been eagerly anticipated, and the wait has been nearly 40 years. Two papers in this issue, by Bricker et al. ( 1 ) on page 96 and Herzig et al. on page 93 ( 2 ), report the identification of a mitochondrial pyruvate carrier (MPC) responsible for this function—a momentous development in the field of bioenergetics with profound implications for treating metabolic diseases.
Tissue imaging using two-photon video rate microscopy

Non-invasive optical diagnosis of cellular and extracellular structure and biochemistry in thick tissue is becoming a reality with the maturation of the two-photon imaging. Today, the slow imaging speed of typical two-photon microscopes is a major hurdle in realizing their clinical potential. We have developed a high-speed two-photon microscope optimized for acquiring 3-D tissue images in real time. The scanning speed improvement of this system is obtained by the use of an air bearing polygonal mirror. The maximum achievable scanning rate is 40 microseconds per line, which is about 100 times faster than conventional scanning microscopes. High-resolution fluorescence images were recorded in real-time by an intensified CCD camera. Using this instrument, we have monitored the movements of protozoas and mapped the collagen/elastin fiber structures in excised human skin.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Road Maps for Learning and Teacher Evaluation

Black, Wilson, and Yao (this issue) make a compelling case for a coherent model of curriculum, pedagogy, and assessment, all built around a well-specified theory of learning. Arguing that dominant ...
Reoperations after myopic laser in situ keratomileusis.

Abstract Purpose To evaluate the results after enhancement of myopic laser in situ keratomileusis (LASIK) using the VISX Star excimer laser. Setting The Buzard Eye Institute, Las Vegas, Nevada, USA. Methods In this prospective study, 52 eyes of 40 patients had LASIK enhancement. The existing flap was lifted and the excimer laser treatment reapplied for the residual refractive error. The VISX Star excimer laser was used for the primary LASIK and the enhancement procedure. Retreatments for undercorrection, regression, and overcorrection were performed after 6 weeks and up to 40 weeks after the primary LASIK. Follow-up was 96% at 1 month, 67% at 6 months, and 71% at 12 months. Results Mean pre-enhancement spherical equivalent was −0.77 diopters (D) ± 0.94 (SD) and mean uncorrected visual acuity (UCVA), 20/60. One year after the enhancement, mean spherical equivalent was −0.13 ± 0.33 D, and mean UCVA was 20/25. Refraction remained stable during the 1 year follow-up, with no retreatment required. After the enhancement, all patients had a UCVA of 20/40 or better. At 1 year, 3% of patients had lost 1 line of best corrected visual acuity and 32% had gained 1 line. No epithelial ingrowth was noted. Conclusion Retreatment for LASIK beginning 6 weeks after the initial procedure proved to be effective with minimal complications and good results. The technique to raise and reposition the flap appeared safe, and complications were few.
Atlantic meets Pacific: Lexicon common to the english-based pidgins and creoles

Abstract Comparing the results of lexicographical studies of English-based creoles in the Atlantic with more recent work on pidgins and creoles in the Pacific, this article examines the common core of lexicon that cannot be traced to current standard English to see what this reveals about the historical relationship between the two groups of restructured languages. The evidence indicates that the lexical base of the Pacific varieties was not only English (including archaic and regional usages), but also the English-based creoles of the Atlantic (often reflecting the influence of their African substrate), and that a number of grammatical as well as lexical items spread from the Atlantic to the Pacific via diffusion.
Formation of hybrid polaritons in an organic-inorganic microcavity at room temperature

We demonstrate hybridization of organic and inorganic excitons via strong coupling to a common microcavity mode. The system consists of 3,4,7,8-napthalenetetracarboxylic dianhydride (NTCDA) and ZnO nanocrystals embedded in a dielectric microcavity held at room temperature.
Electrical and optical switching properties of ion implanted VO2 thin films

Abstract The metal-insulator transition in vanadium dioxide thin films implanted with O + ions was studied. Ion implantation lowered the metal-insulator transition temperature of the VO 2 films by 12 °C compared to the unimplanted ones, as measured both optically and electrically. The lowering of the transition temperature was accomplished without significantly reducing the mid-wave infrared optical transmission in the insulating state for wavelengths > 4.3 μm. Raman spectroscopy was used to examine changes to the crystalline structure of the implanted films. The Raman spectra indicate that ion implantation effects are not annealed out for temperatures up to 120 °C.
Electronic properties of gold on Mo(110): d → s,p charge redistribution and valence band shifts

Abstract The interaction between Au atoms and Mo(110) has been investigated using photoelectron spectroscopy and ab initio self-consistent field calculations. The formation of AuMo bonds induces shifts toward higher binding energy (0.3–0.7 eV) in the core levels and valence d band of gold. This is accompanied by an important redistribution of charge, in which Au loses 5d electrons and gains (6s,6p) electrons. The positive binding-energy shifts in the Au 4f levels and 5d band reflect the effects of a Mo-induced reduction in the Au 5d electron population.
"Holding on" or "coming to terms" with educational underachievement: a longitudinal study of ambition and attainment.

Given mounting aspirations to graduate from college and pervasive difficulties in obtaining a four-year degree, growing numbers of young people in the United States have become “underachievers.” Using data from the ongoing Youth Development Study, the authors examine the prevalence of “holding on” and “letting go” of high aspirations and the precursors of these states as youth move from high school through their mid-twenties. They find that advantage stemming from the family of origin and changing occupational circumstances engender persistence or reappraisal of earlier educational goals. © Wiley Periodicals, Inc.
The Short-Chain Fatty Acids of the Peripheral Blood of Goats

Summary Measureable amounts of acetic, propionic and butyric acids were identified in the peripheral blood of goats. Small amounts of other volatile acids also were present. There were 2.7 to 3.8mg. of total volatile acids per 100ml. in the blood of the young goats and 4.2 to 6.1mg. per 100ml. in the blood of the adult animals. About 75 per cent (molar basis) of the adult levels of volatile acids was acetic acid. Concurrent with the development of the rumen, the glucose level of the blood decreased, while the short-chain fatty acid level increased.
Markov–Nikolskii type inequalities for exponential sums on finite intervals

Let Λn:={λ0<λ1<⋯<λn} be a set of real numbers. The collection of all linear combinations of eλ0t,eλ1t,…,eλnt over R will be denoted by E(Λn):=span{eλ0t,eλ1t,…,eλnt}. Motivated by a question of Michel Weber (Strasbourg) we prove the following couple of theorems. Theorem 1 Let0 0andc2=c2(p,q,a,b)depending only on p, q, a, and b such that c1(n2+∑j=0n|λj|)1q−1p⩽sup0≠P∈E(Λn)‖P‖Lp[a,b]‖P‖Lq[a,b]⩽c2(n2+∑j=0n|λj|)1q−1p. Theorem 2 Let0 0andc2=c2(p,q,a,b)depending only on p, q, a, and b such that c1(n2+∑j=0n|λj|)1+1q−1p⩽sup0≠P∈E(Λn)‖P′‖Lp[a,b]‖P‖Lq[a,b]⩽c2(n2+∑j=0n|λj|)1+1q−1p, where the lower bound holds for all0<q⩽p⩽∞, while the upper bound holds whenp⩾1and0<q⩽p⩽∞.
There and Back Again: Exploring Teacher Attrition and Mobility with Two Transitioning Science Teachers

This study chronicled the professional journeys of two beginning science teachers. The focus of the research effort documents what brought them to science teaching and investigated their resulting career paths. Data artifacts for this instrumental case study approach included: interviews, written survey responses, personal communications and member checks. All data was transcribed and coded into emergent categories using a constant comparative analysis approach. The findings indicated that their decisions to enter and leave teaching were a complex melange of issues that included career disposition, notions of isolation, overarching culture of the school, and future possibilities. However, most striking was their re-entry into teaching on a temporary basis after considerable time away from the classroom, which suggests that teachers develop a sense of agency regarding their career decisions. This may require researchers to reconsider how we view teacher decision-making within the context of teacher attrition and mobility. Implications for science teacher education indicate that some teachers may enter the profession considering teaching to be a transition into a different career path. Secondary science teachers may perceive multiple career options (beyond the classroom) based on their preparation and teaching experience. Further implications and possibilities for science teacher education are discussed.
Collaboration and Organization for Successful Serials Cancellation

ABSTRACT Serials cancellations are dreaded equally by librarians and faculty. Previously, faculty reviewed title lists, and librarians canceled what they recommended. Today's cancellation process is more complex; there has to be a context and a timetable. Reports must include at least data about historical pricing and titles associated with e-packages that are not cancellable. Although libraries' workflows differ, there are basic steps necessary to carry out a successful cancellation process. This joint presentation demonstrated how integrated planning and the use of serials management tools are used to organize complex information into useable data. It takes early and collaborative planning between Collection Development, teaching faculty, and Serials Technical Services to make a dreaded process less painful and more effective. This tactics session was delivered in parts by Susanne Clement and Gaele Gillespie, Head of Collection Development and Serials Librarian, respectively, at Watson Library, Universi...
Stability and change in early childhood classroom interactions during the first two hours of a day

Abstract Early childhood classrooms support children's learning in a variety of ways. Of critical importance are the interactions teachers have with children. The type and quality of classroom interactions vary and can be grouped into three domains: instructional, organizational, and emotional. The purpose of this study is to examine the extent to which the quality of classroom interactions is stable over time and the extent to which certain types of interactions (e.g., organizational) set the stage for other types of interactions (e.g., instructional) during the first two hours of a typical pre-k day. Classrooms (n = 693) were observed during four contiguous observation cycles (20 min for observation, 10 min for ratings) using the Classroom Assessment Scoring System. Stability estimates from autoregressive models showed the quality of classroom interactions was highly stable. Latent difference score models were then fit to determine how these domains of teacher interactions related with one another over time. Contrary to hypotheses, higher levels of Classroom Organization and Emotional Support were not related to positive changes in Instructional Support. However, the final model indicated that Classroom Organization and Emotional Support were positively related to one another over time. That is, higher levels of Classroom Organization were related to higher levels of Emotional Support at the next observation cycle and vice versa. Implications for the understanding of classroom interactions and the measurement of interactions are discussed.
Health Diplomacy and the Enduring Relevance of Foreign Policy Interests

Harley Feldbaum and Joshua Michaud consider the important interplay between foreign policy and global health interests, and introduce a series on Global Health Diplomacy beginning this week in PLoS Medicine.
Strong surface adsorption of aqueous sodium nitrite as an ion pair

Abstract We describe the first detailed experimental characterization of surface adsorption of an aqueous ion pair and quantify the unusual surface behavior of sodium nitrite, a ubiquitous component of natural waters. The onset of unusually strong adsorption at concentrations as low as ca. 0.1 M resembles the controversial ‘Jones–Ray Effect,’ wherein 13 salts exhibited surface tension minima in the millimolar region before resuming the normal linear increase with bulk concentrations. Given the compelling analogy recently found between adsorption of ions to the air–water interface, and the Hofmeister Effects of biochemistry, these results have important implications for the mechanism underlying these phenomena.
A fluorometric assay for angiotensin-converting enzyme activity

A simple and sensitive assay for angiotensin-converting enzyme (ACE; EC 3.4.15.1) activity has been developed which employs fluorescently labeled tripeptides. ACE hydrolyzes dansylphenylalanyl-arginyl-tryptophan or dansyl-phenylalanyl-arginyl-phenylalanine, liberating dansyl-phenylalanine and a dipeptide. Dansyl-phenylalanine partitions quantitatively into chloroform, whereas the substrates are virtually insoluble in chloroform. This allows rapid measurement of ACE activity with high signal-to-noise ratios even when microliter aliquots of human serum are assayed. Inhibition studies of the dansyl-tripeptide cleaving activity of human serum and rat lung, the identity of the products of enzyme action, and the regional distribution of enzyme activity among rat tissues demonstrate that only ACE cleaves these substrates under the conditions employed here. This assay may be useful for the clinical measurement of human serum ACE activity and for research investigations of ACE from a variety of tissues.
The Differential Regulation of p38α by the Neuronal Kinase Interaction Motif Protein Tyrosine Phosphatases, a Detailed Molecular Study

The MAP kinase p38α is essential for neuronal signaling. To better understand the molecular regulation of p38α we used atomistic and molecular techniques to determine the structural basis of p38α regulation by the two neuronal tyrosine phosphatases, PTPSL/PTPBR7 (PTPRR) and STEP (PTPN5). We show that, despite the fact that PTPSL and STEP belong to the same family of regulatory proteins, they interact with p38α differently and their distinct molecular interactions explain their different catalytic activities. Although the interaction of PTPSL with p38α is similar to that of the previously described p38α:HePTP (PTPN7) complex, STEP binds and regulates p38α in an unexpected manner. Using NMR and small-angle X-ray scattering data, we generated a model of the p38α:STEP complex and define molecular differences between its resting and active states. Together, these results provide insights into molecular regulation of p38α by key regulatory proteins.
Disruption of the head direction cell network impairs the parahippocampal grid cell signal

Navigation depends on multiple neural systems that encode the moment-to-moment changes in an animal's direction and location in space. These include head direction (HD) cells representing the orientation of the head and grid cells that fire at multiple locations, forming a repeating hexagonal grid pattern. Computational models hypothesize that generation of the grid cell signal relies upon HD information that ascends to the hippocampal network via the anterior thalamic nuclei (ATN). We inactivated or lesioned the ATN and subsequently recorded single units in the entorhinal cortex and parasubiculum. ATN manipulation significantly disrupted grid and HD cell characteristics while sparing theta rhythmicity in these regions. These results indicate that the HD signal via the ATN is necessary for the generation and function of grid cell activity.
Utilizing symmetry when model-checking under fairness assumptions: an automata-theoretic approach

One useful technique for combating the state explosion problem is to exploit symmetry when performing temporal logic model checking. In previous work it is shown how, using some basic notions of group theory, symmetry may be exploited for the full range of correctness properties expressible in the very expressive temporal logic CTL*. Surprisingly, while fairness properties are readily expressible in CTL*, these methods are not powerful enough to admit any amelioration of state explosion, when fairness assumptions are involved. We show that it is nonetheless possible to handle fairness efficiently by trading some group theory for automata theory. Our automata-theoretic approach depends on detecting fair paths subtly encoded in a quotient structure whose arcs are annotated with permutations, by using a threaded structure that reflects coordinate shifts caused by the permutations.
The Minimization of Public Health Risks in Newspapers after Hurricane Katrina

During natural disasters, mass media facilitate the timely provision of accurate information about health risks to the public. This study informs our understanding of such public health discourse, utilizing a content-analysis of 235 newspaper articles in four major metropolitan newspapers published in the five weeks after Hurricane Katrina hit the Gulf Coast in August 2005. These data reveal that a small and diminishing number of articles included public health information over time, detailed the hurricane impact on affected communities, and used reliable health sources. The implications for future research from a public health and media relations perspective are discussed.
Total Quality Management and Strategic Change: The Pacific Northwest Experience

ABSTRACTThe U.S. Environmental Protection Agency (EPA) currently faces unprecedented challenges. Its requirements, tools, and methods are undergoing change. These changes call for adherence to some basic strategic principles. One of the main tools for accomplishing such strategic change is total quality management. EPA's Seattle office has made changes over the past 4 years that shed light on how to use these principles and tools to meet a vital public need: environmental quality.
Competing in the Third Wave: The Ten Key Management Issues of the Information Age

The article reviews the book “Competing in the Third Wave: The Ten Key Management Issues of the Information Age,” by Jeremy Hope and Tony Hope.
Prebiotic Nucleotide Oligomerization in a Fluctuating Environment: Effects of Kaolinite and Cyanamide

The clay kaolinite was tested for its ability to promote nucleotide oligomerization in model prebiotic systems. Heterogeneous mixtures of clay, water and nucleotide were repeatedly evaporated to dryness at 60°C and redissolved in water in cyclic fashion in the presence or absence of cyanamide and/ or ammonium chloride. With or without cycling, kaolinite alone did not promote the oligomerization of nucleotides at detectable levels. Cycling of clay in combination with cyanamide, however, promoted high levels of condensation to a mixture of oligonucleotides and dinucleotide pyrophosphate without requiring ammonium chloride. Although cycling with clay favored synthesis of dinucleotide pyrophosphate, cycling without clay enhanced formation of oligonucleotides. These results support the hypothesis that the presence of clays in fluctuating environments would have influenced the course of prebiotic condensation reactions.
Femtosecond transient-absorption dynamics of colloidal gold nanorods: Shape independence of the electron-phonon relaxation time

We studied the femtosecond dynamics of colloidal gold nanorods encapsulated in micelles after excitation with 400 nm pulses of 100 fs duration. It is found that the laser heating of the electron gas of gold nanorods with an average aspect ratio of 3.8 leads to the bleaching of both the transverse and longitudinal mode of the surface plasmon oscillation at 520 and 750 nm. The bleach recovers with the same time constant for both the transverse and longitudinal oscillation, for gold nanodots prepared by photothermal reshaping of the rods as well as for nanodots synthesized chemically by citrate reduction (and known to have twin boundaries and surface defects). Since the bleach recovery on the 3 ps time scale is assigned to electron-phonon relaxation processes, these results suggest that phonon dependent relaxation processes in gold nanoparticles are independent of the shape, size, type of the surfaces, or the mode of the surface plasmon, oscillation excited. The fact that the mean free path of the electron in metallic gold is in the nanometer length scale (\ensuremath{\sim}50 nm) raised the question of the importance of surface scattering to the electron-phonon relaxation process in gold nanoparticles. Our previous studies showed little dependence of the relaxation rate of the size of gold nanodots (from 9 to 48 nm). In the present study, the electron-phonon relaxation is measured in gold nanorods, which have different facets from those of gold nanodots.
The determination of nutritional requirements: A mathematical modeling approach

The Saturation Kinetics Model (SKM) has been shown to describe the functional relationship between physiologic responses and nutrients fed in graded amounts. The SKM is based on the concept that an organism is characterized by a sequence of homeostatically constrained steady states. Responses are the result of a series of enzymatically mediated steps, one of which is rate limiting and displays saturation kinetics. The model is descriptive of a wide range of physiological responses and the model equation is continuous in its derivatives. This study examines the usefulness of the application of the SKM to the determination of nutritional requirement levels for growth in the young rat, and provides a basis for the rational formulation of complex mixtures of nutrients (diets) which are designed to optimize some measured performance characteristic in an animal. Using the model, theoretical response curves were constructed based on dietary nutrient concentration, daily weight gain (dW/dt) and daily food intake (dF/dt). Theoretical slopes (first derivative) and efficiency curves were also constructed. Parameters derived from the application of the SKM to rat growth experiments were used to formulate a complete dietary amino acid mix for weanling rats. Dietary ratios and concentrations for indispensable amino acids and arginine were calculated using the parameter K.5. A curve-shift technique was used to determine dietary concentrations for conditionally dispensable and dispensable amino acids. The model was also used to determine a dietary ratio of (IAA + Arg)/(CAA + DAA). Using the dietary amino acid concentrations suggested by the model and an (IAA + Arg)/(CAA + DAA) ratio of 1, a growth response curve was constructed and compared to a similar curve using the amino acid mix of Rogers and Harper. The modeling approach produced a 10-15% improvement in growth over the Rogers and Harper mix. The SKM is discussed in terms of calculating an ideal nutrient ratio and choosing of a desired response level. It was demonstrated that the model can rapidly produce accurate estimates for dietary amino acid levels, while minimizing required numbers of vertebrate animals.
Conformational Dynamics and Proton Relay Positioning in Nickel Catalysts for Hydrogen Production and Oxidation

The [Ni(PR2NR′2)2]2+ complexes (where PR2NR′2 is 1,5-R′-3,7-R-1,5-diaza-3,7-diphosphacyclooctane) are fast electrocatalysts for H2 production and oxidation. Binding of a fifth ligand (CH3CN or BF4–) or chair/boat isomerization has the potential to slow catalysis by blocking the addition of H2 or by incorrectly positioning the pendant amines. We report the structural dynamics of a series of nickel complexes characterized by NMR spectroscopy and theoretical modeling to examine the effects of the fifth ligand for the Ni(II) complexes, including CH3CN, BF4–, Cl–, and H–, as well as the differences in dynamics between the Ni(II) and Ni(0) oxidation states. A fast exchange process was observed for the [Ni(CH3CN)(PR2NR′2)2]2+ complexes, with rates ranging from 104 to 107 s–1 depending on the phosphorus and nitrogen substituents on the PR2NR′2 ligand. This exchange process was identified to occur through a multistep mechanism, which consists of dissociation of the acetonitrile, boat/chair isomerization of each of...
Gas hydrate distribution and carbon sequestration through coupled microbial methanogenesis and silicate weathering in the Krishna–Godavari Basin, offshore India

Abstract The National Gas Hydrate Program Expedition 01 cored ten sites in the Krishna–Godavari basin, located on the southeastern margin of India. A comprehensive suite of pore water solute concentrations and isotope ratios were analyzed to investigate the distribution and concentration of gas hydrate along the margin, in situ diagenetic and metabolic reactions, and fluid migration and flow pathways. Gas hydrate was present at all of the sites cored, and in situ microbial methanogenesis leads to estimates of depth-integrated average gas hydrate saturations that are typically
The Spectrum of School--University Partnerships: A Typology of Organizational Learning Systems.

School–university partnerships are not uni-dimensional projects. Success in these partnerships can be found in loosely-coupled systems such as client–server partnerships and in more tightly-coupled systems such as collaborative development centers. Using a comparative case study approach, we explore two school–university partnership case studies and propose a framework for identifying and evaluating partnerships as learning systems. The structure of the partnership has implications for the focus of organizational learning initiatives that can form the foundation of sustained, systemic internal evaluation.
Observations on degenerate saddle point problems

Abstract We investigate degenerate saddle point problems, which can be viewed as limit cases of standard mixed formulations of symmetric problems with large jumps in coefficients. We prove that they are well-posed in a standard norm despite the degeneracy. By wellposedness, we mean a stable dependence of the solution on the right-hand side. A known approach of splitting the saddle point problem into separate equations for the primary unknown and for the Lagrange multiplier is used. We revisit the traditional Ladygenskaya–Babuska–Brezzi (LBB) or inf–sup condition as well as the standard coercivity condition, and analyze how they are affected by the degeneracy of the corresponding bilinear forms. We suggest and discuss generalized conditions that cover the degenerate case. The LBB or inf–sup condition is necessary and sufficient for wellposedness of the problem with respect to the Lagrange multiplier under some assumptions. The generalized coercivity condition is necessary and sufficient for wellposedness of the problem with respect to the primary unknown under some other assumptions. We connect the generalized coercivity condition to the positiveness of the minimum gap of relevant subspaces, and propose several equivalent expressions for the minimum gap. Our results provide a foundation for research on uniform wellposedness of mixed formulations of symmetric problems with large jumps in coefficients in a standard norm, independent of the jumps. Such problems appear, e.g., in numerical simulations of composite materials made of components with contrasting properties.
Organization for collection development in medium-sized academic libraries

Abstract A survey of medium-sized academic libraries was conducted to ascertain their organizational structure for collection development, and its effect on the activities performed. Two survey instruments were developed, one for chief collection development officers, and one for librarians with collection development responsibilities. The study revealed that librarians defer collection development to other responsibilities and perform few of the activities they feel are desirable for collection development. Librarians in separate collection development departments were less likely to defer collection development to other activities, and performed more collection development activities than their colleagues in other types of libraries. It was recommended that a library of this size locate librarians with primary assignments in collection development in departments established for that purpose.
The metastable constitution and the superconducting transition behavior of ZrTa alloys

Abstract The metastable constitution and superconducting transition temperature have been studied for a series of ZrTa alloys over the composition range from 0 to 20 at% Ta. The transition temperatures of the as-quenched martensitic and retained beta alloys increase as the tantalum content is increased. The precipitation of the metastable omega phase on aging the as-quenched alloys leads to a net decrease in the transition temperature and a broadening of the super-conducting transition. These studies also reveal that ZrTa alloys are potentially important for super-conducting applications.
cDNA cloning of a hnRNP A1 isoform and its regulation by retinol in monkey tracheobronchial epithelial cells

Abstract An isoform of the hnRNP A1 was cloned from a cDNA library of monkey tracheobronchial epithelial (TBE) cells by differential hybridization. The cDNA clone MT77 has an insert of 1756 base pairs and the DNA sequence shares high homology to both human A1 α-type and β-type isoforms with the exception of several differences in the coding and noncoding regions. Like the other two isoforms, MT77 has two polyadenylation sites. A probe prepared from the MT77 clone hybridizes to two message bands at 1.4 and 1.8 kb. Both messages were found in a polysomal preparation, suggesting that both messages are used in A1 protein synthesis. The expression of the A1 gene in monkey TBE cells is stimulated by vitamin A (retinol). The results of nuclear run-on transcriptional assays suggest that this stimulation occurs at the transcriptional level. Furthermore, this effect is not prevented, but superinduced, by cycloheximide. These results suggest that vitamin A may be directly involved in regulating A1 transcription through a mechanism similar to the interactions between the retinoic acid responsive elements and the nuclear receptors of retinoic acid.
Electron Straggling in Thin Foils

A recent experimental investigation of electron straggling distributions reports disagreement with the distribution half-widths of the Landau-Blunck-Leisegang theory. Additional experimental work has been performed in which the angle of incidence of radiation on the foil has been more carefully controlled and a different method of comparison of theory and experiment has been exployed. Discrepancies noted in the previous work with light elements are no longer found.
Statistical probability of worst-case patterns in coincident-current ferrite-core stores

In coincident-current ferrite-core stores, there is a particular pattern of stored information associated with any core which gives a large δnoise signal when that core is read out. Patterns very near to this worst-case pattern also give unwanted δnoise, and this paper calculates the average frequency with which a particular pattern occurs against its nearness to the complete worst-case pattern. For randomly operated 64 2 planes the complete worst-case pattern occurs very rarely, and hence the large δnoise associated with it is rarely encountered. However, lower δnoise voltages from less complete patterns occur significantly often. The mean frequency of occurrence of a particular δnoise is plotted against its magnitude, expressed as a fraction of full worst-case δnoise. In 32 2 and 16 2 planes, complete worst-case patterns occur more frequently. The δnoise voltages associated with them may be expected to occur significantly often, if the planes are randomly operated. A complete worst pattern may also be disturbed in the worst possible way, creating an `absolute' worst-case pattern, which would give the maximum possible δnoise. This is an extremely rare event, for any of the commonly used plane sizes, and even an incomplete absolute worst-case pattern, with half the cores arranged to give little δnoise, is still extremely rare for all but 16 2 planes.
Block copolymer photonic gel for mechanochromic sensing.

Dr. E. P. Chan , Dr. C. M. Stafford Polymers DivisionNational Institute of Standards and Technology100 Bureau Drive, MS 8542, Gaithersburg, MD 20899, USA E-mail: edwin.chan@nist.gov; chris.stafford@nist.gov Dr. J. J. Walish , Prof. E. L. Thomas Department of Materials Science and EngineeringMassachusetts Institute of TechnologyRm 6-113, 77 Massachusetts Avenue, Cambridge, MA 02139, USA