cssi/SciSciGPT-SciSciNet huggingface dataset:
Bit error rate reduction by power shaping in WDM networks with EDFAs

a b s t r a c t The trend in multi-wavelength optical networks is toward dynamic route and wavelength assignment to support burst-switching or packet switching. Where erbium-doped optical amplifiers (EDFAs) are used for multi-wavelength amplifications, the time interval between traffic blocks can be long enough to induce EDFA optical power transients created by abrupt changes in the average input power to the EDFAs and can adversely affect the performance of the network. To mitigate the effects of EDFA optical power transients on optical networks, a method based on power shaping where heads and tails are joined to the beginning and end of a traffic block is proposed. A head (tail) gradually increases (decreases) the channel power by employing a pseudo-random bit sequence in which the probability of a ‘‘1” (‘‘0”) increases from 0 to 0.5. This paper reports experimental results showing that EDFA optical power transients can be significantly reduced with adequate shaping periods. The effects of alternative shaping profiles are examined, and for a linear shaping profile, experiments show that the drop transient deviation is reduced by 0.5 dB while the add transient deviation is reduced by 0.71 dB. We show by lab experiments that the bit error rate induced by wavelength add-drop transients in a chain of EDFAs in an emulated fiber network can be reduced by 25% using power shaping techniques. Power shaping is an economical means of suppressing EDFA optical power transients compared to other physical layer approaches that require the addition of specialized components and can be applied to EDFAs as well as other solid-state and Raman optical amplifiers.
EGF Receptor Activation of the Human Gastrin Gene : A Tale of Two Zinc Finger Transcription Factor Families

Gastrin is one of the oldest and most actively studied of the gastrointestinal peptides. Adult expression of the mature peptide is restricted to the stomach and duodenum. However, it is antral gastrin that is subject to feedback regulation from the counter-regulatory peptide somatostatin as a function of gastric pH. Yet little is known about the molecular steps required to modulate the synthesis of this peptide. Using cell culture models, a GC-rich regulatory element called gERE has been identi-fied that binds two families of zinc finger transcription factors - Sp and ZBP. Competitive binding of these two transcription factor families in association with changes in their phosphorylation state appears to mediate the positive and negative activation of this gene in response to EGF receptor ligands. These findings contribute to our understanding of gastrin gene expression in the presence of the activated ras oncogene, e.g., during colonic transformation.
Effects of EMG Biofeedback on Diabetes

A case is described in which a juvenile-onset insulin-requiring diabetic was given frontalis EMG biofeedback. For 6 years prior to biofeedback training, the subject had been healthy and stable on 22-24 units regular insulin injected once daily. During 8 weeks of standard feedback training for relaxation of frontalis muscle activity, the subject twice reduced her daily insulin dosages. At the end of 8 weeks, the subject was receiving 17-18 units regular insulin daily but was still unstable, sometimes being hyperglycemic, sometimes hypoglycemic. Because of disturbing symptoms associated with this instability, biofeedback was discontinued for 6 months, at which time the subject was again healthy and stable on the equivalent of 18-19 units regular insulin daily. After this period, biofeedback was again given for 1 week, but the subject again became highly unstable and biofeedback was permanently stopped. Caution is suggested when dealing with diabetic patients.
Arsenic, microbes and contaminated aquifers

The health of tens of millions of people world-wide is at risk from drinking arsenic-contaminated well water. In most cases this arsenic occurs naturally within the sub-surface aquifers, rather than being derived from identifiable point sources of pollution. The mobilization of arsenic into the aqueous phase is the first crucial step in a process that eventually leads to human arsenicosis. Increasing evidence suggests that this is a microbiological phenomenon.
Metabolic and Hemodynamic Effects of a Graded Intracoronary Insulin Infusion in Normal and Fat Anesthetized Dogs: A Preliminary Study

Abstract This study evaluated both cardiac hemodynamic and metabolic effects of a graded intracoronary artery infusion of insulin in four normal and five obese anesthetized dogs. Dogs were anesthet...
Matrix polynomials orthogonal on the unit circle and accuracy of autoregressive models

Some new results in the theory of matrix polynomials orthogonal on the unit circle are derived to provide a basis for assessing the accuracy of autoregressive models. In particular, a bound to the weighted norm of the difference between matrix polynomials and their infinite degree limit is obtained which can be used to estimate a priori their rate of convergence. Finally, the connections between some Fourier coefficients of the weight matrix and of its autoregressive approximation are investigated.
Linear Viscoelasticity of Disordered Polystyrene−Polyisoprene Block Copolymer Based Layered-Silicate Nanocomposites

The melt-state linear viscoelastic properties for a series of intercalated nanocomposites are examined. The nanocomposites are based on a short disordered polystyrene−polyisoprene diblock copolymer and varying amounts of dimethyldioctadecylammonium modified montmorillonite. The linear dynamic oscillatory moduli and the stress relaxation moduli are in quantitative agreement and suggest that at short times the relaxation of the nanocomposites is essentially unaffected by the presence of the layered-silicate. However, at long times (or equivalently low frequency), the hybrids exhibit dramatically altered viscoelastic behavior. Hybrids with silicate loadings in excess of 6.7 wt % exhibit pseudo-solidlike behavior, similar to that observed in previous studies of exfoliated end-tethered nanocomposites. On the basis of simple phenomenological arguments, the long time behavior is attributed to the presence of anisotropic stacks of silicate sheets randomly oriented and forming a percolated network structure that i...
Optimal Large Eddy Simulation in One Dimension

How the optimal choice of the filter function in large eddy simulations is related to the spectrum of the turbulent flow is shown. A new formula for the subgrid residuals, which ensures that the exact and filtered flow have the same energy decay profile, is also derived.
Fish Biliary Polycyclic Aromatic Hydrocarbon Metabolites Estimated by Fixed-Wavelength Fluorescence: Comparison with HPLC-Fluorescent Detection☆

Abstract Fixed wavelength fluorescence (FF) was compared to high-performance liquid chromatography with fluorescence detection (HPLC-F) as an estimation of polycyclic aromatic hydrocarbon (PAH) exposure to fish. Two excitation/emission wavelength pairs were used to measure naphthalene- and benzo[a]pyrene (B[a]P)-type metabolites. Early nonmetabolite fluorescent peaks were negligible in HPLC chromatograms of bile of brown bullhead, white sucker, and common carp. Linear regression analysis of FF and HPLC-F data hadr2values between 0.89 and 1.00. Although the linear regression was significant, the absolute HPLC-F and FF values were not equivalent. HPLC-F values for B[a]P-type metabolites were always higher than those determined by FF. For naphthalene-type metabolites there was no consistent relationship between the HPLC-F and FF values. These inequivalencies were possibly due to the variable HPLC-elution patterns caused by the composition of metabolites and the unique fluorescent response exhibited in different solvent concentrations. Nevertheless, mean concentration estimates divided by the value obtained at the reference site were similar by both methods. The FF method can be used to estimate biliary PAH concentrations in these three species and allows PAH metabolites to become a routine measurement end point for environmental assessments.
Congruently melting compounds of CaF2 · rcRF3: Part II

Abstract Crystals of congruently melting CaF 2 · r c RF 3 , where R = Gd, Tb, Dy, Ho, Y and Er, were shown to have the tysonite (LaF 3 -type) structure. From the lattice constants, crystal composition (r c ) and density (p), these compounds are seen to be an extended form of the hexagonal (tysonite) structure of the corresponding RF 3 . In these compounds, Ca 2+ enters substitutionally compensated by a fluoride ion vacancy. The partial molar volume of RF 3 in the compound is a constant of the class of R and equals 37.6 cm 3 .
Government regulations and FDI: a historical perspective of mexico

This article analyzes the development of foreign investment regulations and their impact on FDI flows in Mexico. The study covers the evolution of sectoral and aggregate investment patterns from the independence period to the 1994 Peso crisis and its aftermath. The pattern followed by FDI in Mexico has paralleled the transformation of the Mexican economy itself, focusing initially on the extractive and agricultural sectors, then on manufacturing activities, and recently on the services sector. Mexico has continuously reformed and modernized its regulatory system in order to adapt to internal political changes and changes in the world economic environment. Recent economic reforms and liberalization of FDI regulations have had a major positive impact on capital inflows, but more needs to be done, especially in the area of financial services in order to achieve a higher level of economic efficiency and to prevent financial breakdowns like the one experienced in 1994.
MRSA colonization and the risk of MRSA bacteraemia in hospitalized patients with chronic ulcers

A cohort study of patients with chronic ulcers was performed to estimate the risk of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in a population colonized with MRSA. During a five-year period (January 1990-May 1995), 911 patients with chronic ulcers (CU), as determined by ICD9-CM code search, were admitted to an acute care hospital. Sixty percent (545/911) of these patients with CU had their CU cultured to detect MRSA and 30% (166/545) of these were colonized with MRSA. Among patients with surveillance cultures, those with MRSA colonization had significantly more days of hospitalization and were also more likely to have a central venous catheter during hospitalization compared with patients without MRSA colonization. MRSA bacteraemia occurred in 4% (36/911) of CU patients during the study period and in 6% (32/545) of cultured CU patients. Among the 545 patients who had surveillance cultures, the risk ratio for MRSA bacteraemia when there was MRSA colonization of their chronic ulcer was 16 (95% CI 6-45). Among patients with MRSA colonization, central venous catheter use was the only significant risk factor for MRSA bacteraemia. In 16 of the 28 patients with MRSA bacteraemia and MRSA colonization, the MRSA colonization was identified more than seven days before the bacteraemia. This cohort study identifies MRSA colonized CU patients in an acute care setting as a high-risk population for MRSA bacteraemia.
Topology Design of Multifunctional Compliant Mechanisms With Smart Material Actuation

A method for designing multifunctional compliant mechanisms with smart material actuation is presented. A topology optimization approach is proposed where both passive and active elements can act as design variables. The target application is multifunctional instruments for minimally invasive surgery, which stands to benefit significantly from the advances provided by compliant mechanisms and smart material actuators. Design examples are presented to illustrate the method and the effect of including actuator elements as design variables on the topology and performance of the optimal solution.Copyright © 2002 by ASME
Publisher backtracks on Times atlas claim of dramatic ice loss in Greenland

[1] The newly revised Times Comprehensive Atlas of the World, which many people consider authoritative, includes a set of outstanding maps and illustrations with more than 25,000 mapping updates in addition to incorporating new information about environmental changes on the planet. However, a press release announcing the 13th edition of the atlas, published on 15 September, also indicates that Greenland's ice cover has shrunk by 15% since the publication of an earlier version of the atlas, in 1999. After some glaciologists sharply disputed that number, the atlas publisher, HarperCollins, issued a “clarification” on 20 September that apologizes for the press release but stands by the accuracy of the map. The press release for the atlas indicated that the new edition “has had to erase 15% of Greenland's once permanent ice cover—turning an area the size of the United Kingdom and Ireland ‘green’ and ice-free. This is concrete evidence of how climate change is altering the face of the planet forever—and doing so at an alarming and accelerating rate.”
Juvenile hormone production, juvenile hormone esterase, and juvenile hormone acid methyltransferase in corpora allata of Manduca sexta

Juvenile hormone (JH) secretion by corpora allata (CA) of last instar larvae of Manduca sexta was studied by measuring the rate of JH synthesis in vitro with a radiochemical assay and by analyzing JH esterase and JH acid methyltransferase (JHAMT) activities in CA. CA of 0-day (0–12 hr after ecdysis), 4-day (early wandering larvae), and 7-day (prepupae) animals were used in this study. CA of 0-day larvae showed high rates of JH synthesis, whereas CA of both 4-and 7-day animals did not produce detectable amounts of radiolabeled JH. JH esterase activity was absent in 0-day CA, but high activity was present in both 4- and 7-day CA. However, incubation of older CA in medium containing a potent JH esterase inhibitor did not yield radiolabeled JH, indicating that these glands are unable to methylate JH acids. This conclusion is supported by the observations that JHAMT activity was high in 0-day CA, but absent from older CA. In view of the reported peak of JH in the hemolymph on day 7, an alternative means for producing JH is postulated.
Integrating tools into the classroom

SMILE, a learning environment for collaboration and design, is based on our experience with synchronous and asynchronous collaboration tools in the classroom and sound principles of software and interface design. SMILE provides a more holistic approach to supporting student reasoning and activities rather than the more reductionist tool-based approach we had started with. This more holistic approach focuses on the cognitive processes involved in doing design and learning from that experience, rather than focusing on activities that students are carrying out. This new emphasis has also allowed us to identify ways of integrating scaffolding for metacognitive and reflective reasoning that were not naturally integratable into the previous framework.
Sexual Dimorphism Masks Life History Trade-Offs in the Dioecious Plant Silene Latifolia

Females of dioecious plant species are expected to show greater trade-offs with other life history traits than males because of their high investment in reproduction. We investigated life history traits and resource allocation patterns for both males and females of the dioecious plant Silene latifolia, to document allocation both prior to and after re- productive investment. In addition, the impact of fruit production on subsequent allocation to reproduction and growth was investigated by varying the number of flowers pollinated on females. The mean date of first reproduction was the same for males and females. Early- flowering plants of both sexes invested less in leaf biomass than plants that delayed flow- ering. The percentage of flowers pollinated had a significant effect on how resources were allocated, and on the amount and timing of further flower production. Sexual dimorphism was observed in resource allocation patterns after, but not prior to, investment in repro- duction. Overall, pollinated females were found to have more leaf biomass and invest nearly twice as much in reproduction as males, in spite of an apparent trade-off between leaf production and reproduction within both females and males. We conclude that sexual di- morphism in life history traits that affects resource acquisition causes the resource pool that is allocated to be variable, rather than static, thereby masking the underlying trade- offs.
Estimation of parameters affecting rapid fluid transfers in the whole body. I. Isotonic infusions.

The whole body capillary filtration coefficient (Lp), and tissue compliance (γi) were estimated using a mathematical model of transcapillary water and solute exchange and transient data from experiments. The model describes the dynamic exchanges of water and a generalized solute between the plasma and interstitial compartments as a result of isotonic infusions. An optimization procedure was used to estimate the values of the parameters which gave a “best fit” of the model to transient plasma volume data measured in nephrectomized dogs during and after isotonic infusions. The meanLp for all the experiments ranged from 0.114±0.015 (SEM) ml/min/mm Hg/kg to 0.135±0.019 (SEM) depending upon whether the γi was considered to be constant or to vary in a nonlinear manner. These values are similar to those measured by others in isolated hind limb experiments. The mean γi at normal tissue volume was found to range between 2 and 3 ml/mm Hg/kg. These values indicate that overall tissue compliance is low in agreement with the conclusion of Guyton and thus at variance with the results of others.
Influence of hydrogen bonding upon the TiO2 photooxidation of isopropanol and acetone in aqueous solution

Abstract This study investigates the aqueous photocatalytic degradation of small polar organic compounds (SPOCs) that bear hydrogen-bonding capabilities but do not readily adsorb to the TiO 2 catalyst. The effect of pH on the TiO 2 surface hydroxyl speciation and surface acid/base equilibria was used to elucidate the possible role of hydrogen-bonding interactions in the degradation of acetone and isopropanol in aqueous TiO 2 photocatalytic systems. The kinetic parameters describing the decomposition of these two model compounds were obtained by gas chromatographic analysis of their photoreaction systems and interpreted on the grounds of the Bronsted acid/base properties of the TiO 2 surface speciation and solute hydrogen-bonding numerical scales. The results showed that the fastest initial degradation rates of acetone and isopropanol occurred in a pH range where the optimal conditions for adsorption through hydrogen bonding to the TiO 2 surface and optimum concentration of hydroxyl radicals (OH ) coincide. The fastest degradation constants were observed at pH 6.04 and 8.61 for acetone and isopropanol, respectively. The hypothesis of hydrogen bonding to surface hydroxyl groups presented in this study challenges the common assumption that these model compounds do not adsorb to surface sites, and that their oxidative pathways of degradation only occur via homogeneous-phase reaction with free OH radicals.
Membrane filtration of fullerene nanoparticle suspensions: Effects of derivatization, pressure, electrolyte species and concentration

Particle aggregation is induced in derivatized fullerene (fullerol) suspensions by introducing different counter-ion species (Na(+) Ca(2+) and Mg(2+)) and concentrations. The suspensions are filtered through 20 nm ceramic membranes under different transmembrane pressures, and the removal efficiency is compared. In all cases, the average hydrodynamic radius far exceeded the average pore diameter of the membrane. In the case of mono-valent counter-ions, removal efficiency is influenced by transmembrane pressure, with higher removal efficiencies achieved at lower pressures. In contrast, removal efficiencies of fullerol suspensions destabilized with di-valent ions are insensitive to transmembrane pressure, similar to what was found in the case of non-derivatized fullerene. Scanning Electron Microscope (SEM) images of post-filtration membranes indicate that fullerol aggregates destabilized with Mg(2+) ions deform and partially penetrate the membrane, but are ultimately trapped. The proposed mechanism suggests that di-valent ions act as bridges between fullerol aggregates, forming strong bonds that were not broken under the experimental conditions. These strong bonds may allow aggregated fullerol particles to deform under high pressure, and partially penetrate the membrane. Mono-valent ions are incapable of functioning as bridges, and subsequently, when sufficient pressure is applied, fullerol aggregates will break apart and pass through the membrane.
125 ISOLATION OF MULTILINEAGE STEM CELLS FROM THE PORCINE MAMMARY FAT PAD

Porcine mammary tissue is a dynamic system that undergoes multiple cycles of growth, differentiation, and regression during the life cycle of a female; however, the mechanisms of mammary morphogenesis are not fully understood. The current hypothesis suggests that epithelial stem cells in the terminal end buds interact with surrounding epithelial and stromal cells during mammary tissue development and regeneration. Because the mammary gland of the virgin animal consists largely of a pad of adipose tissue, we propose that adipose-derived stem cells from the mammary fat pad (MFP) may also play a role in the regeneration process. Therefore, the objective of this experiment was to determine whether multilineage stem cells are present in the MFP of gilts. Adipose tissue from the MFP and back fat (BF) from the loin region were harvested from six nulliparous, cycling Yorkshire gilts, approximately 16 mo of age. Methods for isolation of adipose-derived stem cells were modified from those of Malusky and Wheeler (2004; International Society for Stem Cell Research, Proceedings 2nd Annual Meeting, abstr. 248:124). Presumptive stem cells isolated from each tissue type were maintained in vitro in DMEM supplemented with either 10% newborn calf serum (NCS; Rep 1 and 2) or 10% fetal calf serum (Rep 3). BF and MFP cell types formed colonies of fibroblast-like cells within 3 to 5 d. Growth characteristics are shown in Table 1. When the cells were 80% confluent, they were trypsinized and reseeded into 75-cm2 flasks. When cultured in the presence of NCS, both cell types had a progressive decrease in viability, and these cultures could not be maintained past Passage 4. Differentiation of both cell types (Passage 1) into adipogenic, myogenic, and osteogenic lineages are currently underway. Based on morphological evaluations, both cell types are able to differentiate into the aforementioned lineages; however, differentiation of MFP-derived cells occurred at a slower rate and was less pronounced than that of BF-derived cells. These preliminary findings suggest that the MFP likely contains a population of multipotent stem cells; however, at this time, it is not possible to make meaningful statistical comparisons. Further experiments are needed to fully characterize these cells and determine their role in mammary gland morphogenesis. Table 1. Growth of porcine adipose-derived stem cells obtained from the BF or from the MFP This study was partially supported by the Council for Food and Agricultural Research (C-FAR) Sentinel Program and USDA Multistate Project (W-1171).
States as social entities: Re-examining the assumption of mutual disinterest in Rawls’ Law of Peoples

In The Law of Peoples, John Rawls modeled peoples as being independent and mutually disinterested. This is an assumption that mirrors his treatment of individual persons in the domestic context. Th...
Architecturally Induced Multiresponsive Vesicles from Well-Defined Polypeptides. Formation of Gene Vehicles

A series of novel, partially labeled amphiphilic triblock copolypeptides, PLL-b-PBLG-d7-b-PLL, has been synthesized, where PLL and PBLG-d7 are poly(L-lysine hydrochloride) and poly(γ-benzyl-d7-L-glutamate), respectively. The synthetic approach involved the sequential ring-opening polymerization (ROP) of γ-benzyl-L-glutamate and e-Boc-L-lysine N-carboxy anhydrides by a diamino initiator using high-vacuum techniques, followed by the selective deprotection of the Boc groups. Combined characterization results showed that the copolypeptides exhibit high degrees of molecular and compositional homogeneity. The synthesized copolypeptides had similar molecular weights, while the composition of the middle block ranged between 19 and 74% with respect to the monomeric units. Due to the macromolecular architecture of the copolypeptide and the rigid nature of the middle block, the formation of monolayers was favored, and, surprisingly, vesicles were formed in water at neutral pH over the entire compositional range. The...
Software Safety Issues For The Space Station Flight Telerobotic Servicer

NASA has committed to the design and implementation of a Space Station Flight Telerobotic Servicer (FTS) to assist the astronauts in assembly, maintenance, servicing, and inspection tasks on the Space Station and the Space Shuttle. One of the requirements of the FTS is safety. Safety is not solely dependent on the visible hardware components such as manipulators and hydraulic systems. It is also dependent on the underlying software which controls every action of these hardware components. An acceptable level of safety can only be reached by analyzing and implementing safety issues through the conceptualization, design, construction, and operation phases of the FTS. This article discusses three issues that are critical to the FTS safety. These include software design philosophy, software operating models, and a safety subsystem.
Phase identification in aged AuFe alloys using transmission electron microscopy

Abstract The work reported here principally involves a transmission electron microscopic examination of a thin oxide film formed on the surfaces of precipitates in aged AuFe alloys with Fe concentration 25 and 33 at.% on exposure to air at room temperature. By tilting through the reciprocal lattice, bright-field and dark-field image analysis, and double diffraction considerations led to a general picture of the surface layer. The following conclusions were drawn: (a) An Fe3O4 oxide layer forms spontaneously on the surface of precipitates of aged AuFe specimens once the precipitates are exposed to air at room temperature. (b) The orientation relation between the oxide and a precipitate depends on the surface orientation. The Bain relation is obeyed when the precipitate surface is {100}BCC. Both Bain and Nishiyama-Wasserman relations were found on other low index surfaces. (c) The oxide layer is composed of small, discrete particles that epitaxially grow on the surface of the precipitates. (d) Complicated diffraction patterns resulted from the surface oxide layer. The precipitates in AuFe alloys after prolonged aging are simply BCC α-Fe. Ordered precipitates were not found.
A Comparison of Microwave Window Channel Retrieved and Forward-Modeled Emissivities Over the U.S. Southern Great Plains

An accurate understanding of land surface emissivity in terms of associated surface properties is necessary for improved passive microwave remote sensing of the atmosphere, including water vapor, clouds, and precipitation, over land. In an effort to advance this understanding, emissivities are calculated for a 5 ° latitude by 5 ° longitude region in the U.S. Southern Great Plains using a combination of land surface model and physical emissivity model. Results are compared to retrieved values from the Advanced Microwave Scanning Radiometer-Earth Observing System passive microwave observations for cloud-free scenes over a six-year period. The resulting emissivities are compared in the context of surface properties including surface temperature, leaf area index (LAI), soil moisture, and precipitation. The comparison confirms that lower frequency channels respond most directly to the surface soil and its dielectric properties. Differences between retrieved and modeled emissivities are generally lower than 2%-3% and appear to be a function of soil moisture and LAI at frequencies less than 37 GHz. Agreement is better for the vertical polarization channels. At 89 GHz, a large difference is present between retrieved and modeled emissivities in both mean and magnitude of variability, particularly in the summer months. Problems are likely present at higher microwave frequencies in both the retrieved and modeled products, including the inability of the emissivity model to represent liquid water in the form of dew or precipitation interception on the vegetation canopy.
The mood-stabilizing agents lithium and valproate robustly increase the levels of the neuroprotective protein bcl-2 in the CNS

Differential display of mRNA was used to identify concordant changes in gene expression induced by two mood-stabilizing agents, lithium and valproate (VPA). Both treatments, on chronic administration, increased mRNA levels of the transcription factor polyomavirus enhancer-binding protein (PEBP) 2beta in frontal cortex (FCx). Both treatments also increased the DNA binding activity of PEBP2 alphabeta and robustly increased the levels of bcl-2 (known to be transcriptionally regulated by PEBP2) in FCx. Immunohistochemical studies revealed a marked increase in the number of bcl-2-immunoreactive cells in layers 2 and 3 of FCx. These novel findings represent the first report of medication-induced increases in CNS bcl-2 levels and may have implications not only for mood disorders, but also for long-term treatment of various neurodegenerative disorders.
Albert Schweitzer and international health

Albert Schweitzer (1875–1965) was a medical missionary, theologian, philosopher, and musician and the only individual physician to receive the Nobel Peace Prize. His humanitar-ianism had a profound philosophical-religious basis, embodied in the concepts of “ethical mysticism” and “reverence for life.” This paper outlines the relevance of Schweitzer's career to medical education and international health. The growing role of Western physicians in international health and in the prevention of nuclear war (and its medical consequences) is consistent with Schweitzer's active and universalist ethical principles aimed at the alleviation of the suffering shared by mankind. The example of Schweitzer and other individual physicians could be used to enhance participation of individual medical students and physicians in international health programs.
Membrane bridging and hemifusion by denaturated Munc18.

Neuronal Munc18-1 and members of the Sec1/Munc18 (SM) protein family play a critical function(s) in intracellular membrane fusion together with SNARE proteins, but the mechanism of action of SM proteins remains highly enigmatic. During experiments designed to address this question employing a 7-nitrobenz-2-oxa-1,3-diazole (NBD) fluorescence de-quenching assay that is widely used to study lipid mixing between reconstituted proteoliposomes, we observed that Munc18-1 from squid (sMunc18-1) was able to increase the apparent NBD fluorescence emission intensity even in the absence of SNARE proteins. Fluorescence emission scans and dynamic light scattering experiments show that this phenomenon arises at least in part from increased light scattering due to sMunc18-1-induced liposome clustering. Nuclear magnetic resonance and circular dichroism data suggest that, although native sMunc18-1 does not bind significantly to lipids, sMunc18-1 denaturation at 37°C leads to insertion into membranes. The liposome clustering activity of sMunc18-1 can thus be attributed to its ability to bridge two membranes upon (perhaps partial) denaturation; correspondingly, this activity is hindered by addition of glycerol. Cryo-electron microscopy shows that liposome clusters induced by sMunc18-1 include extended interfaces where the bilayers of two liposomes come into very close proximity, and clear hemifusion diaphragms. Although the physiological relevance of our results is uncertain, they emphasize the necessity of complementing fluorescence de-quenching assays with alternative experiments in studies of membrane fusion, as well as the importance of considering the potential effects of protein denaturation. In addition, our data suggest a novel mechanism of membrane hemifusion induced by amphipathic macromolecules that does not involve formation of a stalk intermediate.
A commentary on types of DNA methylation status of the interspersed repetitive sequences for LINE-1, Alu, HERV-E and HERV-K in the neutrophils from systemic lupus erythematosus patients and healthy controls.

A commentary on types of DNA methylation status of the interspersed repetitive sequences for LINE-1, Alu, HERV-E and HERV-K in the neutrophils from systemic lupus erythematosus patients and healthy controls
DATA-DRIVEN NONPARAMETRIC SPECTRAL DENSITY ESTIMATORS FOR ECONOMIC TIME SERIES: A MONTE CARLO STUDY

ABSTRACT Spectral analysis at frequencies other than zero plays an increasingly important role in econometrics. A number of alternative automated data-driven procedures for nonparametric spectral density estimation have been suggested in the literature, but little is known about their finite-sample accuracy. We compare five such procedures in terms of their mean-squared percentage error across frequencies. Our data generating processes (DGP) include autoregressive-moving average (ARMA) models, fractionally integrated ARMA models and nonparametric models based on 16 commonly used macroeconomic time series. We find that for both quarterly and monthly data the autoregressive sieve estimator is the most reliable method overall.
Sulfur–iodine thermochemical cycle: HI decomposition flow sheet analysis

Abstract The analysis of hydrogen iodine (HI) decomposition based on the flow sheet developed by General Atomics (GA) was performed. The accuracy of the thermodynamic model used was validated first by comparing the bubble pressure of the HI–H 2 O mixture of the current analysis with the theoretical analysis of GA. The thermodynamic analysis was also extended to higher temperatures. The whole HI decomposition section was flow sheeted and simulated with Aspen Plus. The process operating conditions were determined for GA results reproducibility of 1 kmol/h of hydrogen production. The influence of the reactive distillation column pressure of the HI decomposition on the operating conditions was studied. The results showed a correlation between the boil-up rate and the pressure of the reactive distillation column.
Development of a Curriculum Framework for Water Education for Educators, Scientists, and Resource Managers.

Abstract This study sampled a total of 268 people involved in natural resource research and management education: elementary (n = 59), middle (n = 39), secondary (n = 44), K-12 (n = 22), and nonformal (n = 30) educators; university researchers (n = 24); and natural resource agency managers (n = 50) representing every state in the United States. A traditional Delphi survey approach was used to determine what concepts, skills, and affects should be included in the National Project WET water and water resource curriculum framework. The analysis resulted in an 80-item curriculum framework to guide development of educational materials in this area. Differences among regions of the country and between educators and resource managers are noted.
An Examination of Personal and Situational Factors Which Affect Female Managers and Their Employees

This study examined personal characteristics of 19 male and 47 female employees and 38 female bosses, and situational factors which may affect women in management. Variables included sex, age, atti...
Curettage and electrodesiccation as a method of treatment for epitheliomas of the skin

The technique of curettage and electrodesiccation in the treatment of carcinomas of the skin is described. The 5-year cure rate for this technique compares favorably with the 5-year cure rate for other methods of treatment. Curettage and electrodesiccation subjects the patient to a minimum of pain and inconvenience. Situations in which other methods of treatment are preferable are presented.
Making authentic science accessible to students

Authentic activities are important in promoting inquiry because they provide natural problem-solving contexts with high degrees of complexity. This study designed and studied effective inquiry tasks through transforming content, scientific thinking, and resources featured in scientists' authentic practices. This study investigated how 59 inner-city 6th grade students performed in real-time forecasting situations involving fronts and pressure systems. Forecasts were evaluated in terms of prediction agreement, meteorological entity consideration, explanation type, and scientific knowledge use because these four categories reflected inquiry features emphasized in the forecasting task. Results show that real-world situations that mapped closely onto students' content understandings, rather than those with naturally occurring complex patterns, helped students perform inquiry. Key ideas discussed in this paper include the importance of using authentic situations to develop rich understandings about scientific k...
Cuba: A Personal Journey

This article is a personal reflection of a social work professor’s journey to Cuba and the impact this experience had on her teaching and understanding of identity. The trip to Cuba provided an opportunity to develop a deeper understanding of the influence of a parent’s culture and immigrant experience in shaping our sense of self. In turn, this understanding was applied to teaching a diversity course for students enrolled in a graduate social work program. Implications for teaching social work are discussed.
Force characteristics of nickel-titanium tension coil springs.

Abstract Nickel-titanium closed coil springs are commonly used for space closure. The springs possess a high resistance to permanent deformation and the potential for relatively constant force delivery. A study was designed to determine whether relatively constant forces can be delivered and whether the force magnitudes approach the manufacturer’s targeted force values. Heavy, medium, and light springs were activated 15 mm at temperatures that ranged from 15°C to 60°C. The forces were measured during deactivation with a specially constructed force transducer temperature chamber. Relatively constant forces can be achieved with an over-activation procedure that allows relaxation to the desired activation. The light springs delivered forces that were near the targeted force; no difference was found between the heavy and medium springs in the constant force range. The force magnitudes varied markedly depending on mouth temperature. (Am J Orthod Dentofacial Orthop 1999;15:498-507)
Recordings of His Bundle and Other Conduction Potentials in Children

A technique for recording His bundle potentials in man has recently been described and utilized in the study of the AV conduction system in normal and pathological states. These previous adult studies have dealt with defining the His bundle potential as well as making a more precise assessment of the nature of AV block possible in a way hitherto not attainable. Thirty-five children between 3 months and 13 years of age with various congenital cardiac defects were studied. All had normal sinus rhythm and normal AV conduction and included both non-operative and post-operative patients. The His bundle potential was recorded in 34 of the 35 patients, the one exception being a post-operative tetralogy of Fallot. The HQ interval varied from 22 to 60 msec. In 26 of the 35 patients, a potential was recorded which probably represented the AV node. Furthermore, in 27 of the 31 children who did not have complete right bundle branch block, a right bundle branch potential was also recorded. Additionally, a left bundle branch was recorded in 5 patients. In a two-week-old infant with congenital complete AV block, the presence of a left bunde branch pottential in association with the absence of the His bundle or right bundle branch potentials suggests that the impulse originated in or near the left bundle branch. The technique of intracardiac His bundle recording has been shown to be both feasible and practical in children of all ages. Further studies are in progress to define in more detail, the mechanisms of congenital disturbance of AV conduction.
Mechanical strain applied to human fibroblasts differentially regulates skeletal myoblast differentiation

Cyclic short-duration stretches (CSDS) such as those resulting from repetitive motion strain increase the risk of musculoskeletal injury. Myofascial release is a common technique used by clinicians...
Making lemonade: The challenges and opportunities of forced reference serials cancellations; one academic library's experiences

In a panel discussion on weeding the reference collection presented at the 1991 ALA Midwinter Conference, David Tyckoson of SUNY-Albany described the reference collection as an index to the general library collection.1 I would like to go a step further. The reference collection is the skeleton of the general collection. It provides at least basic information on most subjects even when the library does not have comprehensive or specialized resources. If the reference collection is the skeleton, then serials are the backbone of that skeleton. Reference librarians are expected to produce timely, accurate information on any and all subjects. This requires upto-date directories, biographical sources, indexes, and statistical compendia--in other words, ongoing subscriptions. No matter how emaciated the body, we have always been confident that the skeleton was strong and intact, supporting library information services. However, widespread economic ills have begun to threaten those bones.
Rescuing failures: can large data sets provide the answer?

Secondary analyses of large data sets including that by Gonzalez et al1 have repeatedly reported on an association between failure to rescue after surgery, or death after amajor complication, andoutcome.2-4While fewprovide insight as to how to change this relationship, these analyses can generate hypotheses about why high-mortality hospitals have higher rates of failure to rescue. For example, studies have identified higher rates with lower levels of intensive care unit facilities,5 poor nurse practice environments,6 and less aggressive treatment style.7However, these data sets are not granular enough to determine whether these are actual causes of failure to rescueor just surrogates for other factors such as better teamwork and communication, which Gonzalez and colleagues have suggested as a potential solution. Identifying the correct targets for improvement is essential as interventions are likely to bemultifaceted, resource intensive, and costly. Researchers need to move beyond documenting associations to performing hospitaland patient-level studies to understand where and why failures to rescue occur and how they can be prevented. Delay in diagnosing and treating complications may be related to processes, structure, or both. Thus, should interventions be directed at improving specific processes involved in postoperative care or at enhancing infrastructure and resources? If a combination of interventions is required, which ones should be instituted first or deserve the most attention? Furthermore, how does context influence the effectiveness of interventions to reduce failure to rescue? Interventions that work in one setting may not be successful in others. Should improvement efforts instead focus on changing the safety culture? Until these questions can be answered, associations between failure to rescue and mortality will continue to exist and hospitals will continue to fail with patients ultimately suffering the consequences.
Silylation of Acrylamide for Analysis by Solid-Phase Microextraction/Gas Chromatography/Ion-Trap Mass Spectrometry

A method for quantitative analysis of acrylamide has been developed for use with headspace solid-phase microextraction (SPME). In the method, acrylamide undergoes silylation with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) to form the volatile N,O-bis(trimethylsilyl)acrylamide (BTMSA). Once formed, BTMSA is readily extracted from the headspace over the silylation reaction using a 100 microm poly(dimethylsiloxane) SPME fiber. A series of experiments was undertaken to optimize the amount of BSTFA, the silylation reaction temperature, the silylation reaction duration, and SPME sampling duration to maximize the analytical sensitivity for BTMSA. Acrylamide levels were quantified relative to a [13C3]-acrylamide internal standard using gas chromatography/ion-trap mass spectrometry (GC/MS) in the single ion monitoring mode. An analytical working curve was constructed and found to be linear over the 4 to 6700 ppb acrylamide range investigated with a limit of detection of 0.9 ppb. The native acrylamide levels of three commercial cereals were measured using the optimized analytical method. Quantitative standard additions of acrylamide to the cereal matrixes demonstrated complete recovery of the spiked acrylamide.
Raman and infrared spectra, r0 structural parameters, and vibrational assignments of (CH3)2PX where X = H, CN, and Cl

Abstract The infrared (3500–80 cm−1) and Raman spectra (3500–40 cm−1) of gas/or liquid and solid (CH3)2PX with X = H (DMH), CN (DMCN) and Cl (DMCl) as well as (CD3)2PH have been recorded and complete vibrational assignments are given for all three molecules. To support the spectroscopic study, ab initio calculations by the Moller–Plesset perturbation method to second order MP2(full) and density functional theory calculations by the B3LYP method have been carried out. The infrared intensities, Raman activities, vibrational frequencies and band contours have been predicted from MP2(full)/6-31G(d) calculations and these theoretical quantities are compared to experimental ones when available. By utilizing the previously reported microwave rotational constants for DMH and DMCN along with the MP2(full)/6-311+G(d,p) predicted values, adjusted r0 structural parameters for DMH and DMCN have been determined. The heavy atom parameters for DMH are: r0(P C3,4) = 1.8477(30) A, ∠ CPC = 99.88(50)° and for DMCN: r0(N C) = 1.159(3), r0(C P) = 1.790(3), r0(P C4,5) = 1.841(3) A, ∠ NCP = 175.7(5), ∠ CPC4,5 = 97.9(5) and ∠ CPC = 100.7(5)°. Barriers to internal rotation are reported. The experimental values are compared to the corresponding values of some similar molecules whenever possible.
Metabolism and energy requirements in pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive disorder of coenzyme A homeostasis caused by defects in the mitochondrial pantothenate kinase 2. Patients with PKAN present with a progressive neurological decline and brain iron accumulation, but general energy balance and nutrition status among these patients has not been reported. To determine if defects in PANK2 change basic energy metabolism in humans, we measured body composition, resting energy expenditure, dietary intake, and blood metabolites among 16 subjects with PKAN. Subjects had a broad range of disease severity but, despite the essential role of coenzyme A in energy metabolism, the subjects had remarkably normal body composition, dietary intake and energy metabolism compared to population normal values. We did observe increased resting energy expenditure associated with disease severity, suggesting increased energy needs later in the disease process, and elevated urinary mevalonate levels.