cssi/SciSciGPT-SciSciNet huggingface dataset:
Collective Behavior of the Closed-Shell Fermi Gas

We propose an unconventional description for the ground state and collective oscillations of the two-component normal Fermi gas with two-body zero-range interactions. The many-body problem can be accurately reduced to a linear, one-dimensional Schroedinger equation in a single collective coordinate, the hyperradius R of the N-atom system which is the root mean square radius. The calculated properties of the Fermi gas ground state are shown to agree accurately with results from the Hartree-Fock (HF) approximation over a wide range of interspecies scattering lengths. The breathing mode excitation frequency deviates qualitatively from HF predictions, but we show that this reflects a failure of the HF approach for this observable.
Diagnosing and Treating Breast Cancer in Elderly Women: A Call for Improved Understanding

Breast cancer is the most common nondermatological malignancy in women, and the incidence increases with age until the eighth decade. Breast cancer pathology and biology appear to be different in elderly patients than in younger ones, and therefore treatment recommendations cannot be generalized from one group to the other. Most elderly women can tolerate breast cancer surgery without significant complications and should be offered a definitive surgical procedure. Improved mechanisms to predict which patients will tolerate and benefit from various therapies are under development. Because most breast cancers in the elderly are hormone responsive, hormonal therapy remains the mainstay of systemic treatment in the adjuvant and metastatic settings. Chemotherapy can be used in elderly women, but treatment decisions must be individualized based upon risk-benefit analyses. Elder-specific studies are underway to identify the most-efficacious and best-tolerated therapies for breast cancer in this population. Primary care physicians must be aware of these issues to provide adequate counseling and care to these patients.
Some Remarks on Teaching: Three Insights Into the Purpose and Process of Teaching Medical Students

Interaction with medical students as a physician and teacher for 40 years has taught me many things, among them three insights into the purpose and process of teaching which have served me well as a teacher and which seem worthwhile to share. Originally, I believed that the role of teachers was to provide information to students; by giving of my own knowledge, I believed that my students would learn. Despite great effort, this process never seemed as successful as expected. The reason for failure now seems obvious. Our students are adults. They learn by thinking actively and by doing; the teacher9s role is to be supportive of the learning process.
Birth of inflationary universes

A cosmological model is proposed in which the Universe is created by quantum tunneling from "nothing" into a de Sitter space. The tunneling is described by a de Sitter---Hawking---Moss instanton. After the tunneling, the model evolves along the lines of the inflationary scenario. It is argued that at any time there exist parts of the Universe which are still in the de Sitter phase, while other parts have already recollapsed. This model does not have a big-bang singularity and does not require any initial or boundary conditions.
Evidences of Transformative Learning in Service-Learning Reflections

Abstract A major shift in university course work involves activities outside the traditional classroom in which students are required to apply knowledge from the coursework in real-life service-learning environments. Such complex learning contexts generate a level of disequilibrium or anxiety that may or may not result in transformative learning. This phenomenological study examined student reflective writings from an Honors service-learning course at a medium-sized mid-western university for evidences of transformative learning, the precipitating disequilibria, and the significant pedagogical structures underlying growth. All students learned and all students encountered disquieting experiences; however, only half the participants exhibited varying levels of transformative learning. Results indicate that transformative learning requires time, space, and appropriate scaffolding to develop or augment personal internal systems of adjusting what one thinks and how one thinks about new information and experiences. The results further suggest that a framework of iterative service experiences, grounded in course content, readings, faculty-student-community dialogue, and continuous, thoughtfully designed, reflective practice can maximize transformative learning potentials. Future research should continue to explore how service-learning is experienced by individual participants and what contextual factors are essential for increasing the likelihood that transformative learning will occur.
Games That Art Educators Play: Games in the Historical and Cultural Context of Art Education

Games have played an important role in modern educational methodologies. Beginning with the work of luminaries like Froebel, Montessori, and Dewey and continuing through the Cold War, the counter-culture movement of the 1960s and ’70s, and into the present day, shifts in educational practice can be traced historically using the lens of games, where concepts like play, win strategies, cooperation, and engagement figure prominently in curricular structures. The author investigates how games have been discussed in art education literature, linking how the use of games in art educational environments significantly reflects the sociopolitical contexts of the 20th century.
Prospective change in daily walking over 2 years in older adults with or at risk of knee osteoarthritis: the MOST study

Summary Objective Radiographic disease and knee pain are thought to decrease physical activity in people with knee osteoarthritis (OA), but this has not been formally studied. We examined change in objectively measured daily walking over 2 years and evaluated the association of certain risk factors with reduced walking among adults with or at risk of knee OA. Design Steps/day over 7 days were collected at baseline and 2 years later in subjects with or at risk of knee OA from the Multicenter Osteoarthritis Study using a StepWatch. We evaluated the presence of radiographic knee osteoarthritis (ROA), knee pain, worsening of ROA and pain over 2 years, obesity, depressive symptoms, living situation, catastrophizing, fatigue, widespread pain and comorbidities with 2-year change in daily walking using regression models adjusted for potential confounders. Results 1318 met inclusion criteria (age 66.9 ± 7.7, 59% women, BMI 30.6 ± 5.9) and walked 126 ± 1700 steps/day fewer steps at 2 years (95% CI [−218, −35]). People with depressive symptoms at baseline walked 455 fewer steps/day [−872, −68], and there was a trend for people with ROA worsening to walk 183 fewer steps/day [−377.5, 11.7]. No other factors met statistical significance for change in daily walking. Conclusion Adults with or at risk of knee OA experienced only minimal declines in daily walking over 2 years. Nonetheless, depressive symptoms and may be worsening ROA are associated with a decline in steps/day in adults with or at risk of knee OA.
Congenital cytomegalovirus infection of the brain: imaging analysis and embryologic considerations.

PURPOSE To analyze the cortical gyral patterns and myelination patterns in a series of patients with congenital cytomegalovirus infections involving the central nervous system, to correlate them with known developmental events, and to develop a consistent theory regarding their embryogenesis. METHODS The MR (11 patients) and CT (four patients) studies of 11 patients with congenital cytomegalovirus infections involving the brain were retrospectively reviewed. Analysis was made of myelination patterns, cortical gyral patterns, other areas of maldeveloped brain, and focal brain lesions. RESULTS Lissencephaly was found in four patients. These patients had very thin cerebral cortices, extremely diminished volume of white matter, delayed myelination, small cerebella, and very enlarged lateral ventricles. Focal areas of dysplastic cortex, presumably polymicrogyria, were found in five patients. These patients had slightly thickened irregular cerebral cortices, slightly diminished volume of white matter, delayed myelination, variably small cerebella, and slightly enlarged lateral ventricles. Two patients had normal cerebral cortices, slightly diminished volume of white matter, delayed myelination, normal cerebella, and slightly enlarged lateral ventricles. Periventricular lesions, representing calcification, or perhaps blood, were seen in all groups. CONCLUSIONS We postulate that the patients with lissencephaly suffer injury before 16 or 18 weeks gestational age, whereas those with regions of polymicrogyria are injured between approximately 18 and 24 weeks gestational age. Those with normal gyral patterns are probably injured during the third trimester and may have active infections at birth. Moreover, we propose that the finding of cerebellar hypoplasia and myelination delay in association with diffuse lissencephaly or cortical dysplasia should suggest the diagnosis of congenital cytomegalovirus infection.
Shear-induced aggregation of mammalian synovial fluid components under boundary lubrication conditions

Author(s): Banquy, X; Lee, DW; Das, S; Hogan, J; Israelachvili, JN | Abstract: The lubricating and structural properties of different mammalian synovial fluids in thin films undergoing shear between two mica surfaces are studied in detail using a surface force apparatus (SFA). A 10-13 nm thick film of synovial components (proteins, lipids, and polymers) adsorbs on the mica surfaces in less than an hour of incubation time, and induces a strong repulsion between the surfaces that prevents them from coming into contact. Upon shearing, the structure of the confined synovial fluid changes dramatically when sheared above a "critical" shear rate of about 2 s-1 (corresponding to approximately 40 nm s-1). Above this critical shear rate and up to at least 70 μm s-1, the proteins and biopolymers in the fluid gradually aggregate to form a homogenous gel layer on each mica surface. As shearing continues, the gel layer gradually breaks up into discrete/individual gel particles that can roll in the contact keeping the sheared surfaces far apart even under high compressive loads (pressure P ≈ 20 MPa). These particles eventually become elongated and finally behave as roller bearings. This mechanism is consistently observed for three mammalian synovial fluids and two types of surfaces suggesting that it actually occurs in articular joints and prostetic implants in vivo. The implications of these findings for joints and prosthetic implants structure and lubrication are discussed; in particular the formation and function of the lamina splendens. Shear-induced aggregation of synovial fluid components is observed under boundary lubrication conditions. The aggregation process starts with the formation of a gel-like layer on the surfaces, which ultimately leads to the formation of rod-like aggregates. These aggregates provide enhanced wear protection and lubrication to the surfaces using rolling friction instead of pure sliding friction. This mechanism suggests new design criteria for future bioinspired lubricants. © 2014 WILEY-VCH Verlag GmbH a Co. KGaA, Weinheim.
Resolution, uncertainty, and whole Earth tomography

[1] Using the arrival times of 10 distinct phases from the International Seismological Center catalogue (P, S, PP, PcP, SS, ScS, PKPab, PKPbc, PKPdf, SKSac) and two sets of differential times (SS − S410S and SS − S660S), we estimate the P and S velocity structure of the whole Earth (mantle, outer core, and inner core), boundary topography of four interfaces within the Earth, hypocentral relocation parameters, and station corrections. The entire catalogue is relocated and reassociated using the radial velocity model ak135. Both P and S phases are used in the relocation of over 41,000 events. In depth, isotropic velocity variations within the Earth are parameterized by 22 layers. Lateral variations in shear and compressional velocity within the layers are represented by one of two grids. In the mantle, each layer is subdivided into 4560 equal-volume cells, of dimension 3° × 3° at the equator. However, in the outer and inner core, the cell size is increased to 6° × 6°. This change in grid spacing accounts for decreasing cell volumes with depth and variations in sampling between the mantle and core. Previous attempts using a fine grid throughout the Earth resulted in poor resolution of core structure. With the current grid, the resolution of velocity heterogeneity in the mantle and outer core is comparable. In the upper and midmantle, the well-resolved cells lie beneath Eurasia and a narrow zone surrounding the mantle beneath the Pacific basin. In the lowest mantle, the resolution decreases significantly. An examination of the averaging kernels associated with six locations near the base of the mantle reveals the significant lateral and vertical averaging inherent in estimates of compressional velocity. In well-sampled regions of the outer core, we are able to resolve compressional velocity variations in our 6° × 6° cells. However, velocity variations in the inner core are poorly constrained at the scale of our blocks. In well-sampled regions of the mantle and outer core model, parameter standard deviations remain below 0.25%. For much of the inner core, the standard deviations are quite large, exceeding 0.5%. Narrow, high-velocity anomalies are imaged in the upper mantle, associated with subduction zones. In a number of locations, such as beneath the Americas, these features extend well into the lower mantle. In the outer core, heterogeneity is generally lower in magnitude, of the order of 0.5%. The most notable feature in the outer core is a systematic shift to slightly higher velocity. In addition, we find a roughly symmetric distribution of heterogeneity at the base of the outer core. Compressional velocities are generally higher in the equatorial regions and lower at the poles.
Infusion of dye molecules into Red clover necrotic mosaic virus

The Red clover necrotic mosaic virus capsid is utilized to package and release molecules through reversible depletion and re-addition of divalent cations.
Note on Modulation

It is shown that the usual nonperiodic solution of d2y -+ e(1 + k cos t)y = 0 dt2can always be interpreted in the stable case as a wave undergoing simultaneous phase and amplitude modutlation. An analysis is carried through on this basis.
Impact of the FDA black box warning on physician antidepressant prescribing and practice patterns: opening pandora's suicide box

After a decade-long decline, annual suicide rates in American children and adolescents increased in 2004. A report released in February 2007 described an 18% increase in the suicide rate in persons aged 1 through 19 years between 2003 and 2004. The incidence of suicide, the third-leading cause of death in 15 to 19-year-old Americans, increased from 7.3 to 8.2 per 100,000 persons in 2004. Language: en
Convergence of the method of fundamental solutions for Poisson’s equation on the unit sphere

Solutions of boundary value problems of the Laplace equation on the unit sphere are constructed by using the fundamental solution $$\Phi (\bf{x},\bf{y})=\frac{1}{4\pi \|\bf{x}-\bf{y}\|},\qquad \bf{x}, \bf{y}\in R^3.$$ With the use of radial basis approximation for finding particular solutions of Poisson's equation, the rate of convergence of the method of fundamental solutions is derived for solving the boundary value problems of Poisson’s equation.
Nuclear winds and the narrow-line emission from active galaxies

This paper discusses active galaxy narrow-line emission in the context of a supersonic wind generated by the active nucleus, a nuclear wind. Wind acceleration can naturally produce the inferred narrow-line cloud velocities as well as those of the broad-line and broad absorption line clouds with only a weak dependence on the parameters of the active nucleus. The primary obstacle to wind acceleration of emission-line clouds is the destructive effect of instabilities; however, the stability and structure of wind-confined clouds remain areas of future research. Observations, particularly of the Seyfert galaxy NGC 1068, are interpreted in the context of nuclear winds.
A Survey of Methods for Pure Nonlinear Integer Programming

The subject of this paper is a classification and discussion of algorithms for solution of nonlinear pure integer programming problems. The survey is organized by characterizing the mathematical form of the nonlinear optimization problems addressed by the various algorithms. If any method can be used without changes to solve mixed integer nonlinear programming problems that fact is mentioned in the description of the algorithm. However algorithms which must be applied only to mixed integer problems are not surveyed.
Deamination of Glutamic and Aspartic Acids by Geotrichum candidum

Strains of Geotrichum candidum were isolated from the surface of a commercial sample of Limburger cheese and from raw milk. Growth of the isolates in an acidified tryptone-yeast extract medium was accompanied by a rise in the pH of the medium from 3.5 to above 7.0 Ammonia production, as indicated by Nesslerization, was associated with the deamination of glutamic and aspartic acids. The first reaction in the production of ammonia from glutamic acid, isomerization to beta-methylaspartic acid, required vitamin B12 and the second reaction, the deamination of beta-methylaspartic acid to mesaconic acid and ammonia, was dependent on magnesium and potassium. The conversion of aspartic acid to fumaric acid and ammonia required magnesium. These minerals were in sufficient amounts in the Limburger cheese for optimum deaminase activity.
Support effects on CO hydrogenation over Ru/Zeolite catalysts

Hydrogenation of carbon monoxide at 101.3 kPa has been studied over a series of ion-exchanged Ru catalysts supported on NaX, NaY, KL, Na mordenite, and HY zeolites. The type of zeolite had pronounced effects on the activity and selectivity of the Ru. The specific activity would appear to be related to the dispersion of reduced ruthenium in the zeolite. Methane selectivity, however, seems to be strongly influenced by the type and concentration of alkali cations remaining in the ion-exchanged zeolite. These cations appear to promote chain growth much as traditional alkali promoters would, though perhaps more indirectly. Due to bifunctional properties of the zeolite-supported catalysts, a significant fraction of C/sub 4/ was in the form of isobutane. Formation of isobutane seems to be related to either the Si/Al ratio in the zeolites or the concentration of the remaining alkali cations, but not to the OH concentration. In addition, H/sub 2/ chemisorption at 25/sup 0/C was increasingly suppressed as the Se/Al ratio of the zeolite support increased. Both the formation of isobutane and the suppression of H/sub 2/ chemisorption may be related to the acid strength of the OH groups present, which is a function of the Si/Al ratio of themore » zeolite.« less
Trace element crystal chemistry of mantle eclogites

Rare earth element (REE) concentrations have been measured using instrumental neutron activation analysis on clean separates of primary minerals from 11 eclogite samples from the Bobbejaan and Roberts Victor kimberlites, South Africa. Samples were selected to reflect minimal secondary alteration and represent a broad range of eclogite compositions from coesiteand corundum-grospydites through magnesian bimineralic eclogites. Correlations between REE concentrations and major-element compositions suggest that garnet and clinopyroxene crystal chemistry are the dominant control on REE distribution and that these approach solidstate equilibrium distributions. Reconstructed wholerock REE concentration variation with whole-rock major-element compositions are consistent with an origin by high-pressure igneous fractionation followed by reequilibration to lower temperatures at pressures in excess of three GPa.
Surface Interactions of Iodine Vapor with Tungsten

The interactions of iodine vapor with a clean tungsten surface were studied by first adsorbing the iodine on the tungsten ribbon and then thermally desorbing the adlayer. The composition of the desorption products was determined with a time‐of‐flight mass spectrometer. No evidence is found for the formation of surface compounds. Only iodine atoms and, at higher coverages, iodine molecules populate the surface. Both desorptions are first order, and the most tightly bound atom state has a desorption energy of ∼80 kcal. A second, lower‐energy atom state is populated at higher coverages. An estimate of the iodine molecule desorption energy gives ∼40 kcal.
Propagation of 3-D Beams Using a Finite-Difference Algorithm: Practical Considerations

We discuss practical aspects of the use of the finite-difference, alternating-direction implicit (ADI), numerical solution of the paraxial wave equation, for the free-space propagation of light beams. Results of calculations solving the finite-difference equations are compared with fresnel-integral solutions. Calculations are for round beams, but the field is represented in cartesian coordinates. Modes for empty unstable resonators are also obtained using the finite-difference algorithm and are compared with fresnel-integral solutions.
Measuring Spatial Knowledge: Effects of the Relation between Acquisition and Testing

Performance in human-robot interaction is related to the operator's mental map of the space in which the robot travels. Accordingly, accurate assessment of mental maps will be important for the design of human-robot interfaces. The present research used a factorial design experiment to examine two methods for acquiring spatial knowledge (reading a map vs. navigating in the space), three methods of testing spatial knowledge (drawing a map, navigating through the space, and estimating point-to-point distances. The results showed that performance in the navigation test was influenced by factors unrelated to the navigated distance, whereas map drawing especially was closely related to the actual distance. Map drawing resulted in a stronger relation between map distance and actual distance in the map training condition than in the navigation training condition. The results are interpreted in terms of transfer appropriate processing, and are applied to human-robot interface design.
Trapezoidal Wing Experimental Repeatability and Velocity Profiles in the 14- by 22-Foot Subsonic Tunnel

The AIAA Applied Aerodynamics Technical Committee sponsored a High Lift Prediction Workshop held in June 2010. For this first workshop, data from the Trapezoidal Wing experiments were used for comparison to CFD. This paper presents long-term and short-term force and moment repeatability analyses for the Trapezoidal Wing model tested in the NASA Langley 14- by 22-Foot Subsonic Tunnel. This configuration was chosen for its simplified high-lift geometry, publicly available set of test data, and previous CFD experience with this configuration. The Trapezoidal Wing is a three-element semi-span swept wing attached to a body pod. These analyses focus on configuration 1 tested in 1998 (Test 478), 2002 (Test 506), and 2003 (Test 513). This paper also presents model velocity profiles obtained on the main element and on the flap during the 1998 test. These velocity profiles are primarily at an angle of attack of 28 degrees and semi-span station of 83% and show confluent boundary layers and wakes.
Extracellular Angio-Associated Migratory Cell Protein Plays a Positive Role in Angiogenesis and Is Regulated by Astrocytes in Coculture

The extracellular form of angio-associated migratory cell protein (AAMP), a recently discovered protein, plays a positive role in angiogenesis and can be regulated by astrocytes. Angiogenic activities are inhibited by an affinity-purified, polyclonal antibody generated to recombinant AAMP. Inhibition of endothelial cell tube formation was previously shown and now endothelial cell migration assays using this antibody show dose-dependent inhibition (75%) of endothelial cell migration. Also, antisense inhibition has been used to determine the effects of reducing total AAMP (extracellular and intracellular forms). An AAMP-specific antisense oligonucleotide that targets a region near its amino terminus, anti-MES, inhibits (45%) total AAMP production by bovine aortic endothelial cells (BAECs), compared to a negative control oligonucleotide. Paradoxically, comparable use of antisense-MES results in a 27% increase in BAEC motility. Decreased cellular production of total AAMP (via antisense) that results in an increase of endothelial migration contrasts with antibody inhibition of extracellular AAMP that decreases migration. This indicates compartment-specific roles for AAMP in angiogenesis. Transwell cocultures of human astrocytes and BAECs increase (53%) the amount of extracellular AAMP found associated with endothelial cells. Therefore, regulation of extracellular AAMP by astrocytes is hypothesized to aid in angiogenesis of the nervous system. Extracellular AAMP's positive role may be either as a promoter or as a permissive protein in this process.
Truncated cystatin C in cerebrospiral fluid: Technical artefact or biological process?

Cystatin C, a low molecular weight cysteine proteinase inhibitor present in human body fluids at physiological concentrations, is more expressed in cerebrospinal fluid (CSF) than in plasma. Mass spectrometric characterization showed that after 3 months of storage of human CSF at -20 degrees C, cystatin C was cleaved in the peptide bond between R8 and L9 and lost its eight N-termini amino acids, whereas this cleavage did not occur when stored at -80 degrees C. This truncation occurred in all CSF samples studied irrespective of the underlying neurological status, indicating a storage-related artefact rather than a physiological or pathological processing of the protein. These results stress the importance of optimal preanalytical storage conditions of any sample prior to proteomics studies.
Effect of sugar and acid on the acceptability of frozen yogurt to a student population.

One hundred and forty-one college students tasted and rated on a nine-point hedonic scale their degree of liking for nine samples of vanilla frozen yogurt varying in sugar and lactic acid. Subjects were also asked to complete a questionnaire about consumption of frozen yogurt and other dairy products. Degree of liking differed significantly among samples, and the samples best liked were those with the lowest acidity, .23 to .29%, independent of sugar concentration. Degree of liking of frozen yogurt failed to correlate with dairy product consumption or hunger at the time of testing. No significant difference existed between male and female students for overall degree of liking of frozen yogurt or overall dairy product intake, yet the questionnaire revealed a significantly higher consumption of frozen yogurt among female students. The results of this study suggest that, for the student population tested, frozen yogurt should combine the sensory properties of ice cream (low acidity) with the nutritional properties of yogurt (low fat, active enzyme culture).
Human embryonic stem cells as a research model for human biology and diseases

As a pluripotent and unlimited cell source, human embryonic stem (hES) cells offer the promise to develop new transplantation therapies and to characterize early events of human cell development and diseases. We have developed a novel method to generate a broad range of hematopoietic cells including immune modulating leukocytes from hES cells in culture. This study provides the first evidence that differentiated hES cells can generate functional APCs in addition to other myeloid and erythroid cells in culture (Zhan, Lancet, 2004). In addition to cell culturebased methods, we are also exploring the transgene expression approach to enforce and enhance hematopoietic differentiation from hES cells in vitro. We have been working on the role of two signaling pathways, Wnt/beta-catenin and Notch/CBF1/Hes1, for hematopoietic differentiation as well as self-renewal or maintenance of undifferentiated hES cells. Both pathways are greatly activated in differentiating hES cells induced by a variety of methods. Our data point to a role of the Wnt/beta-catenin activation in promoting cell proliferation (essential for both HES cell selfrenewal and differentiation), instead of hES cell maintenance (Dravid, Stem Cells, 2005; Cai, Cell Res, 2007). Notch signaling activation is not required for self-renewal or maintaining undifferentiated hES cells or trophoblast differentiation, but required for differentiation commitment to the 3 embryonic germ layers. We conclude Notch signaling is important for hES cells to exit from the undifferentiated state and/or enter to certain differentiated states (realizing differentiation potential or pluripotency), but not necessarily self-renewal of the undifferentiated state. We have started to use hES cells as a genetic/developmental model for human diseases lacking functional products of a defined gene. To this end, we have established hES cell lines deficient in PIG-A, which is required for GPIanchored cell surface protein synthesis and mutated in hematopoietic stem cells in PNH patients. We found that PIG-A deficient hES cells were capable of self-renewal or committing differentiation into the 3 embryonic germ layers after differentiation induction. However, hES cells deficient in PIG-A and GPI-anchored proteins failed to form trophoblasts induced by embryoid body formation or BMP4, a unique characteristic of hES cells different from mouse ES cells. The defect in trophoblast formation was due to reduced BMP4 signaling in the PIG-A deficient hES cells (Chen, submitted). The effects of PIG-A and GPI-anchored protein deficiency in hematopoiesis from hESderived hematopoietic precursors will be discussed. These studies highlight the excitement that hES cells provide an unprecedented and much needed research tools for understanding the development and function of human cells and tissues, complementing or validating studies using murine or other small animal models. Cell Research (2008) 18:s8. doi: 10.1038/cr.2008.98; published online 4 August 2008
Why continuum electrostatics theories cannot explain biological structure, polyelectrolytes or ionic strength effects in ion–protein interactions

Continuum electrostatics models for ions in water provide apparent long range electrostatic explanations for the forces on ions. However the electro-chemical free energy of solvation of ions resides largely in the first two water layers, which control the interfacial behavior of the ions and require explicit modeling to capture their distinctive behaviors. The resulting short range forces produce such surprising charge density-dependent behaviors as ion adsorption onto nonpolar surfaces, like charge aggregation of ions, and substantial ion pairing preferences, which arise largely from the affinity of specific ions for individual water molecules. Specific ion effects controlled by the local water affinity of the ion show a diagnostic change of sign between strongly hydrated Na(+) and weakly hydrated K(+) and between strongly hydrated F(-) and weakly hydrated Cl(-), in both cases marking the strength of water-water interactions in bulk solution, a critical benchmark missing from continuum electrostatics models.
Disparities in Access to Fresh Produce in Low-Income Neighborhoods in Los Angeles

Background Access to fresh produce and other healthy foods differs between poor ethnic and wealthier non-ethnic neighborhoods. Given the need to improve access, emergency food organizations, such as food pantries, can provide assistance. Food pantry clients, many living in poor ethnic neighborhoods, are at highest risk for inadequate intake of fruits and vegetables as emergency food assistance often does not include a supply of fresh produce. This study examines the extent to which food pantry clients live within reasonable walking distance of stores carrying fresh produce, and it proposes a strategy to increase accessibility of produce to those clients. Methods Addresses for 3985 food pantry clients residing in Pomona, California, in 2003 and 84 food stores categorized as selling a "variety of produce" or "limited produce" were geocoded using geographic information systems technology in 2004. A 0.8-km network buffer was used to measure access to stores. Cluster areas with high densities of food pantry clients, or hot spots, were determined. Results Forty-one percent of Pomona food pantry clients were within walking distance of a store with fresh produce. Eighty-three percent were within walking distance of stores with limited produce, and 13% were not within walking distance of either store type. Seventeen cluster areas of food pantry clients accounted for 48% of clients with no access to a produce store. Conclusions Using individual-level data allowed for the identification of significant numbers of food pantry clients with limited access to stores carrying a variety of fresh produce. Identification of the location of high concentrations of food pantry clients provides a potential solution to increase fresh fruit and vegetable access via mobile produce trucks.
Defined benefit versus defined contribution pension plans: How are the interests of employees and the public best served?

Prior to the enactment of the Employee Retirement Income Security Act of 1974 the rate of formation of defined benefit retirement plans exceeded the rate of formation of defined contribution retirement plans. Following its enactment the trend has been reversed. This article reviews the development of public policy with respect to privately sponsored retirement benefits, takes note of the legislatively mandated regulatory distinctions between defined benefit and defined contribution plans, outlines the distinctions between the plans from the perspective of plan sponsors versus plan participants, and questions the appropriateness of the movement away from defined benefit plans in terms of public policy objectives regarding retirement income security.
Phosphoproteins of the avian erythrocyte.

Abstract The mature avian erythrocyte provides a favorable model for studies relating nuclear structure, function, and composition. Phosphoproteins have been recognized among nuclear constituents, although no detailed functions have been described for them. Earlier studies of avian erythrocytes may have included plasma membrane phosphoproteins in the nuclear fraction. Plasma membrane and nuclear nonhistone proteins from chicken erythrocytes have been separately isolated and characterized with respect to total phosphorus and [ 32 P]phosphate incorporation. The nuclear nonhistone proteins were 11.7-fold richer in total phosphorus, but phosphorus reached a 2.3-fold higher specific radioactivity in the plasma membrane proteins during a 3-h incubation. Both fractions yielded radioactive phosphoamino acids after acid hydrolysis. The proteins were separated by electrophoresis on 4–30% gradient polyacrylamide gels in the presence of sodium dodecyl sulphate. A 92-kilodalton, plasma membrane-specific protein was the most radioactive constituent. Six to seven phosphoprotein bands were apparent from both the plasma membrane and the nuclear fractions and three bands appeared to be common to both. The circulating erythrocyte maintains its structural integrity without benefit of macromolecular synthesis for an extended period. The protein-bound phosphorus and the continued phosphorylation described herein may reflect activities devoted to the maintenance of structure.
Easy access to the Wilkinson tris(tert-butylimido)nitridomanganate(VII) complex from commercially available starting materials

Abstract The synthesis of dark green, crystalline Li2[Mn(NtBu)3 N] ∙ LiCl(THF)2 in two steps from commercially available starting materials is described. Reaction of MnF3 with LiNHtBu and LiCl and subsequent workup represents an easy access to this historic complex. 1H NMR, absorption and FT-IR spectra, and single crystal X-ray diffraction data are reported and confirm the identity of the material.
Photoluminescence characteristics of polar and nonpolar AlGaN/GaN superlattices

High quality Al0.2Ga0.8N/GaN superlattices (SLs) with various (GaN) well widths (1.6 to 6.4 nm) have been grown on polar c-plane and nonpolar m-plane freestanding GaN substrates by metal-organic chemical vapor deposition. Atomic force microscopy, high resolution x-ray diffraction, and photoluminescence (PL) studies of SLs have been carried out to determine and correlate effects of well width and polarization field on the room-temperature PL characteristics. A theoretical model was applied to explain PL energy-dependency on well width and crystalline orientation taking into account internal electric field for polar substrate. Absence of induced-internal electric field in nonpolar SLs was confirmed by stable PL peak energy and stronger PL intensity as a function of excitation power density than polar ones.
ROS: double-edged sword for leukemic cells

Comment on Chandra et al, page [2501][1] There is increasing evidence that chemotherapeutic drugs can work via acceleration of reactive oxygen species in human malignancy. In this issue of Blood , Chandra and colleagues describe the activity of the unique molecule adaphostin, a tyrphostin kinase
Pharmacological modification of unit activity of the cerebral ganglion of the mussel, Mytilus edulis and the control of ciliary movement.

Abstract 1. Direct application of serotonin (5-HT) or weak concentrations (10−7 M) of acetylcholine (ACh) to the cerebral ganglion of the mussel, Mytilus edulis, produced a 300–600% increase in unit activity from the cells of the cerebral ganglion and a similar increase in ciliary beating of the gill. 2. Prior application of bromolysergic acid (Bol) prevented this effect. 3. Exogenous application of dopamine (DA) decreased both cerebral ganglion unit activity and ciliary beating. 4. Following section of the cerebrovisceral connective, ciliary beating steadily decreased and electrical stimulation of the branchial nerve no longer excited gill activity.
A role for Yin Yang-1 (YY1) in the assembly of snRNA transcription complexes

The RNA polymerase (pol) II and III human small nuclear RNA (snRNA) genes have very similar promoters and recruit a number of common factors. In particular, both types of promoters utilize the small nuclear RNA activating protein complex (SNAP(c)) and the TATA box binding protein (TBP) for basal transcription, and are activated by Oct-1. We find that SNAP(c) purified from cell lines expressing tagged SNAP(c) subunits is associated with Yin Yang-1 (YY1), a factor implicated in both activation and repression of transcription. Recombinant YY1 accelerates the binding of SNAP(c) to the proximal sequence element, its target within snRNA promoters. Moreover, it enhances the formation of a complex on the pol III U6 snRNA promoter containing all the factors (SNAP(c), TBP, TFIIB-related factor 2 (Brf2), and B double prime 1 (Bdp1)) that are sufficient to direct in vitro U6 transcription when complemented with purified pol III, as well as that of a subcomplex containing TBP, Brf2, and Bdp1. YY1 is found on both the RNA polymerase II U1 and the RNA polymerase III U6 promoters as determined by chromatin immunoprecipitations. Thus, YY1 represents a new factor that participates in transcription complexes formed on both pol II and III promoters.
Giant Nernst effect and lock-in currents at magic angles in (TMTSF)2PF6.

We have measured the thermoelectric signal along the a axis in (TMTSF) 2 PF 6 at 10 kbar as a function of the orientation of the applied magnetic field Resonantlike Nernst signals were found with a dramatic sign change as the field was rotated through the "Lebed magic angles." The sign change indicates that the electrical current is "locked in" to the magic angle (interchain) directions for field alignment close to, but on either side of, the magic angles. The amplitude of signals near these angles is many orders of magnitude larger than expected from conventional Boltzmann transport theory.
Physicians and a smoke-free society.

The National Cancer Institute (NCI), Bethesda, Md, has established a goal of reducing the cancer mortality rate in the United States by 50% by the year 2000. This means that more than 200 000 premature deaths will be prevented in that and each ensuing year. While this goal will be reached by action on a number of fronts, eg, changing dietary habits, developing new treatment techniques, and utilizing existing state-of-the-art treatment techniques, an essential element will be an accelerated rate of smoking prevention and cessation in the United States. This is particularly true if we are to become the smoke-free society envisioned by the Surgeon General. See also p 1039. Since the publication of the first Surgeon General's Report on Smoking and Health in 1964, 1 more than 30 million Americans have stopped smoking. While no one approach appears to have been preeminent as a means of stopping smoking (although
Structural Plasticity in Influenza Virus Protein NS2 (NEP)

The cellular nuclear transport machinery relies on the assembly of specialized transport complexes between soluble transport receptors, transport substrates, and additional accessory proteins. This study focuses on the structural characteristics of influenza virus protein NS2 (NEP), which interacts with the nuclear export machinery during viral replication, and has been proposed to act as an adapter molecule between the nuclear export machinery and the viral ribonucleoprotein complex. For this purpose, we have purified recombinant NS2 under nondenaturing conditions, and have investigated its structure and aggregation state using optical spectroscopy, differential scanning calorimetry, as well as hydrodynamic techniques. Our results indicate that isolated NS2 exists as a monomer in solution, and adopts a compact, but very flexible conformation, which shows characteristics of the molten globule state under near physiological conditions. Proteolytic sensitivity suggests that, despite its overall plasticity, the structure of NS2 is heterogeneous. While the C terminus of the protein adopts a relatively rigid conformation, its N terminus, which is recognized by the nuclear export machinery, exists in a highly mobile and exposed state. It is proposed that the flexibility observed in the nuclear export domain of NS2 is an important element in the recognition of substrate proteins by the nuclear export machinery.
Enhancement of Heat Transfer in Miniaturized Channels Using Ferrohydrodynamic Convection

Heat transfer in miniaturized channels and slots in electronic cooling applications is restricted by relatively low convection due to flow limitations. The flow is generally laminar and heat transfer in these small geometries is usually conduction limited. We have proposed the use of ferrofluids as coolants in the presence of a nonuniform external magnetic field to enhance the heat transfer. A magnetic ferrofluid consists of a stable colloidal dispersion of subdomain magnetic nanoparticles in a liquid carrier that remain suspended due to their thermal Brownian energy. Under a varying external magnetic field (B) , a ferrofluid experiences a local volumetric body force (M.∇)B. The magnetization M of the ferrofluid is coupled with the fluid temperature through its density and magnetic susceptibility. In our simulations, a strong magnetic field is considered to be applied by placing an edge pole adjacent to one of the walls of a rectangular channel. The channel is assumed to carry a pressure-driven ferrofluid flow. The resulting flowfield is predicted by numerically solving the coupled mass, momentum, energy, and Maxwell’s equations. A parametric study is performed to identify the influence of the magnetic field strength on the temperature distribution and the resulting heat transfer. A comparison based on the local and average Nusselt numbers shows that there is a significant heat transfer augmentation due to the magnetic field.Copyright © 2003 by ASME
A Miniature Hybrid L-Band Battery Operated FSK Transceiver

This paper describes a miniature transceiver which consists of three main sections: 1) a receiver portion with three active mixers, thick film limiter, and modem; 2) a transmitter portion with three active upconverters and a gated power amplifier; and 3) a local oscillator section containing a temperature compensated crystal oscillator which is shared by both transmitter and receiver. Design techniques to minimize current drain include active mixers and gated functions. Absolute frequency stability is provided by the interrogator's own frequency accuracy. Construction employs two Epsilam-10* boards sandwiching a Teflon** fiberglass voltage distribution layer. Use of these construction techniques alleviates the need for conventional high-cost cavity construction.
Quantitative proteomics approach towards the identification of yeast endoplasmic reticulum flippase

Phospholipids in cells are mainly synthesized in the cytoplasmic leaflet of the endoplasmic reticulum (ER) and the newly made polar lipids must flip-flop rapidly across biological membranes to sustain cellular life. But this 'flipping' is energetically costly as well as its translocation rate is low. As a solution to this, cells have membrane proteins that function as lipid transporters - 'flippases', proteins that facilitates the rapid, bi-directional, energy-independent flip-flop of phospholipids between the cytosolic and lumenal leaflets of the ER membrane. Flippases have been known to play a key role in membrane stability as well as in the mechanism by which cells avoid being killed by macrophages. Candidate flippases have been implicated in human diseases that include intrahepatic cholestasis, angelman syndrome, autism, tangier disease, macular dystrophy and adrenoleukodystrophy. Establishing the primary function of candidate flippases and how they contribute to cell function and human disease is becoming a central issue in biology. Although the flippases that operate at the plasma membrane of eukaryotes at the expense of ATP hydrolysis resulting in unidirectional lipid flipping have been identified, the ATP-independent bi-directional flippases that translocate lipids in specialized compartments such as the ER have not yet been identified at their molecular level. The objective of the current study is to identify ER flippases in yeast Saccharomyces cerevisiae using a quantitative proteomics approach based on stable isotope labeling by amino acids in cell culture (SILAC). Yeast cells were grown in synthetic medium supplemented with either 'light' or 'heavy' lysine. Proteins extracted from unlabeled (light) cells were further fractionated by velocity sedimentation in a glycerol gradient and flippase activity of each fraction was quantified by a phospholipid reconstitution-based procedure. An aliquot of labeled (heavy) extract (containing equal amount of protein by weight) was added to each light fraction. The mixed fractions were then subjected to in-gel digestion followed by quantitative proteomic analysis using mass spectrometry. The data obtained were processed using MaxQuant followed by Spearman correlation analysis for identification of proteins with enrichment profiles matching that of the activity profile. The potential flippase candidates were tested for their activity using genomically tagged yeast strains.