cssi/SciSciGPT-SciSciNet huggingface dataset:
Intramolecular Hydrogen Bonding in Disubstituted Ethanes. A Comparison of NH···O- and OH···O- Hydrogen Bonding through Conformational Analysis of 4-Amino-4-oxobutanoate (succinamate) and Monohydrogen 1,4-Butanoate (monohydrogen succinate) Anions

Relative strengths of amide NH···O- and carboxyl OH···O- hydrogen bonds were investigated via conformational analysis of succinamate and monohydrogen succinate anions with the aid of vicinal proton−proton NMR couplings and B3LYP DFT quantum mechanical calculations for a variety of solvents. New experimental results for succinamate are compared with those obtained from previous studies of monohydrogen succinate. While some computational results for monohydrogen succinate were published previously, the results contained herein are the product of a more powerful methodology than that used earlier. The experimental results clearly show that intramolecular hydrogen-bond formation is more favored in aprotic solvents than in protic solvents for both molecules. Furthermore, the preference of the succinate monoanion for the gauche conformation is much stronger in aprotic solvents than that of succinamate, indicating that the OH···O- hydrogen bond is substantially stronger than its NH···O- counterpart, despite the ∼5 kcal cost for formation of the E configuration of the carboxyl group needed to make an intramolecular hydrogen bond. The actual energy differences between formation of internal hydrogen bonds for monohydrogen succinate and succinamate anion were estimated by comparison of the relative values of K_1 of the respective acids in water and DMSO by a procedure first developed by Westheimer. Recent theoretical work with succinamate highlights the necessity of considering substituent orientational degrees of freedom to understand the conformational equilibria of the central CH_2−CH_2 torsions in disubstituted ethanes. Similar methodology is applied here to succinic acid monoanion, by mapping potential-energy surfaces with respect to the CH_2−CH_2 torsional, carboxyl-substituent rotational, and carboxyl−proton E/Z isomeric degrees of freedom. Boltzmann populations were compared with gauche populations estimated from the experimentally determined coupling constants. The quantum mechanical results for succinamate show a much weaker tendency toward hydrogen bonding than for the succinic acid monoanion. However, the theoretical methods employed appear to substantially overestimate contributions from intramolecularly hydrogen-bonded structures for the succinic acid monoanion when compared with experimental results. Natural bond orbital analysis, applied to the quantum mechanical wave functions of fully optimized gauche and trans structures, showed a strong correlation between the population of amide σ^*_(N-H) and carboxyl σ^*_(O-H) antibonding orbitals and apparent hydrogen-bonding behavior.
Darcy velocity computations in the finite element method for multidimensional randomly heterogeneous porous media

For numerical modeling of transport of contaminants through porous media, an accurate determination of the velocity field is a prerequisite. Some previous schemes of obtaining the Darcian velocity field through numerical solution of the flow equation result in a physically inconsistent velocity distribution in a heterogeneous medium. A scheme that is consistent with the physics of velocity variation near material interfaces is examined and compared with previous schemes. Numerical simulations are used to demonstrate the capability and accuracy of the proposed scheme for randomly heterogeneous porous media.
Fluorometric microbore amino acid analyzer: the construction of an inexpensive, highly sensitive instrument using o-phthalaldehyde as a detection agent.

Abstract The construction of a highly sensitive microbore amino acid analyzer is described. It is based on a standard column chromatographic separation technique with fluorometric detection utilizing o -phthalaldehyde. This analyzer has several desirable features: low column chromatographic pressure, high sensitivity, and easy maintenance. Good precision at a level of 10 pmol is obtained and as little as 0.2 μg protein has been hydrolyzed for composition analysis. It incorporates the use of the single-column method and constant molarity buffers to shorten the analysis time. It is fully automatic and capable of analyzing 130 samples within 7 days with attention required only for reloading 20 samples while the instrument is in operation. Amino acid composition determination based on the peak area and the peak height is discussed.
Strain differences in adrenalectomy-induced alterations in nicotine sensitivity in the mouse

Adult mice of four inbred strains (A, BUB, C57BL, DBA) and two selectively bred lines [Long-Sleep (LS) and Short-Sleep (SS)] were tested for differences in glucocorticoid regulation of nicotine sensitivity. One week following adrenalectomy (ADX), animals were tested for nicotine sensitivity in a battery of tests that included acoustic startle response, Y-maze activity (line crosses and rearings), heart rate and body temperature. Although each type of animal tested had increased nicotine sensitivity in at least one of the test battery measurements, there was clear evidence for a genetic influence on the scope of ADX-induced changes in sensitivity. LS animals had the largest increase in sensitivity with altered responses in four of five tests following ADX. The sensitivity of DBA animals was increased in two tests while for A, BUB, C57BL and SS animals, only one test was affected. ADX-induced alterations in nicotine sensitivity could not be explained on the basis of changes in nicotinic receptor number since changes were consistent across strains. The mechanism by which ADX causes increased nicotine sensitivity is not known. However, these data support the hypothesis that nicotine sensitivity is modulated by adrenal glucocorticoid secretion and also suggest that this phenomenon is under strict genetic control.
1041 REDUCED PRODUCTION OF HISTAMINE RELEASE ENHANCING FACTOR (HREF) BY CORD BLOOD MONONUCLEAR CELLS

The liberation of histamine and other inflammatory mediators constitute a major component of host defense. HREF is a unique cytokine produced by PHA stim. mononuclear cells (MC) that may be an important mediator of inflammatory responses. Incubation of granulocytes with HREF enhanced subsequent basophil histamine release (BHR) induced by anti-IgE, f-Met peptide, and the Ca ionophore A23187 (124±43%, 139±40%, and 66±29% enhancement). HREF production was dependent on the number of cells cultured, PHA cone., and duration of culture. Conditioned media containing HREF was active after heat (70°C × 30 min), absorption by activated lymphocytes, and thyroglobulin removal of PHA. HREF produced by cord blood MC of 19 newborns produced significantly less enhancement of anti-IgE induced BHR than adult controls (39±30% vs 53±31% enhancement, p<.05). This was not related to impaired PHA responsiveness. Both stim. and unstim. cord MC incorporated greater 3H thymidine than controls (p <.001). T cell enriched (TCE) populations produced greater HREF than unfrac. or T-depleted (TD) populations (TCE 73±32% enhancement; unfrac. 42±20%; TD 43±25%; N=13, p <0.05). Functional cellular immune deficiency in newborns and deficient lymphokine synthesis by cord lymphocytes have been previously reported. HREF is a potentially important determinant of histamine release and reduced capacity for its production may contribute to the relative immunodeficiency of newborns.
Scaling procedure and finite volume computations of phase-change problems with convection

Abstract In this paper, solidification problems are investigated from two angles, namely, the issue of wide disparity of important length scales present in phase change processes, and the finite volume based computational techniques developed to simulate such processes. To appropriately handle phase change phenomena, a scaling analysis is presented to bring out the relevant physics at the macroscopic and morphological scales. It is demonstrated that an appropriate choice of the scale is necessary to obtain numerical solutions economically. Two different finite volume techniques are described in this paper. The first technique involves a mixed Eulerian/Lagrangian approach, where the interface is explicitly tracked by means of marker particles, and the field equations are solved on an underlying fixed, finite volume grid. The other approach is an enthalpy model which incorporates the interface information in a field variable called the phase-fraction. This volume averaged technique enables the implicit handling of the interface as part of the solution procedure at the cost of smearing out the discontinuity. Two different phase-fraction update techniques are presented and their relative effectiveness and performance discussed. A continuous ingot casting problem modelled by accounting for the interaction of phase-change and turbulent transport is also presented and compared with experimental results.
Quantification of polarization in biological tissue by optical coherence tomography

A multiple-channel polarization-sensitive system based on optical coherence tomography was built to measure the Mueller matrix of scattering biological tissue. The Jones matrix of a sample can be determined with a single scan and subsequently converted into an equivalent non-depolarizing Mueller matrix. As a result, the system can be used to measure the Mueller matrix of soft tissue. Birefringence, axis orientation, and diattenuation can be extracted.
Large Area Growth and Electrical Properties of p-Type WSe2 Atomic Layers

Transition metal dichacogenides represent a unique class of two-dimensional layered materials that can be exfoliated into single or few atomic layers. Tungsten diselenide (WSe2) is one typical example with p-type semiconductor characteristics. Bulk WSe2 has an indirect band gap (∼1.2 eV), which transits into a direct band gap (∼1.65 eV) in monolayers. Monolayer WSe2, therefore, is of considerable interest as a new electronic material for functional electronics and optoelectronics. However, the controllable synthesis of large-area WSe2 atomic layers remains a challenge. The studies on WSe2 are largely limited by relatively small lateral size of exfoliated flakes and poor yield, which has significantly restricted the large-scale applications of the WSe2 atomic layers. Here, we report a systematic study of chemical vapor deposition approach for large area growth of atomically thin WSe2 film with the lateral dimensions up to ∼1 cm2. Microphotoluminescence mapping indicates distinct layer dependent efficiency....
Androgyny, sex-role orientation, and homosexism.

Summary In a study of the relationship between homosexism and both psychological androgyny and normative sex-role orientation, questionnaires were administered to 87 male and 119 female college students. Results indicate that males were less androgynous, more traditional in sex-role orientation, and more homosexist than females. Homosexism was significantly related to sex-role orientation among males and to both androgyny and sex-role orientation among females. Homosexism appeared to contribute to maintaining traditional sexual differentiation among both males and females. This occurred more on the normative than on the psychological level.
Visual Literacy and Visual Politics: Photojournalism and the 2004 Presidential Debates

While newspapers use conventional images to accompany reporting on presidential debates, the rhetorical aspect of these images is illustrated through an examination of the 2004 debates. In this essay, the author first establishes oppositional positioning and mirroring as visual literacy conventions that augment those previously identified by Paul Messaris in his examination of advertising images. Second, a critical analysis of the photographs depicting the first 2004 debate, in particular, demonstrates how photo editors deployed visual conventions that either intensified clash or neutralized candidate performance fragments to produce a false symmetry despite a discordant reality. In subsequent debates, however, many editors employed alternate visual conventions that provided an improved visual balance between fairness and accuracy.
Mechanism of Amine Sensitization in Shocked Nitromethane

The mechanism of amine sensitization of shocked nitromethane was investigated using time-resolved optical absorption spectroscopy in the visible. Neat nitromethane and mixtures of nitromethane with six different (primary, secondary, tertiary, and di-) amines were shocked to within 12−17 GPa peak pressure using step wave loading. Despite the small amine concentrations, profound differences were observed in the absorption spectra of neat and sensitized nitromethane. The changes in the absorption spectrum of reacting neat nitromethane consisted of irreversible broad-band (450−650 nm) loss of transmission through the sample after a short induction time. In contrast, a transient absorption peak at 525 nm developed in the spectra of the reacting mixtures. This feature did not depend on the particular amine used. We assign it to a transient intermediate formed in the shocked mixtures during the early stages of decomposition. On the basis of our analyses and the data available in the literature, we identify the i...
Multiparticle quantum mechanics obeying fractional statistics

We obtain the rule governing many-body wave functions for particles obeying fractional statistics in two (space) dimensions. It generalizes and continuously interpolates the usual symmetrization and antisymmetrization. Quantum mechanics of more than two particles is discussed and some new features are found.
Use of Germanium diodes at high frequencies

THE PRICES of television receivers are being reduced almost continuously, and at the same time designers are striving to reduce their weight, size, and tube complement. Today, with engineers designing receivers for use on new ultrahigh-frequency channels, efficient, inexpensive converters are needed.
An Experimental Study of the Effect of Global Solid Fraction and Surface Material on Couette Granular Flow

The flow of solid granular material has been proposed as an alternative lubricant to conventional liquid lubricants. Since granular flows are also in numerous industrial and natural processes, they have been the subject of numerous studies. However, it has been a challenge to understand them because of their non-linear and multiphase behavior. There have been several past experiments, which have gained insight into granular flows. For example, previous work by the authors sheared grains in a two-dimensional annular shear cell by varying the velocity and roughness [1]. The present experimental work attempts to further insights from the previous work by specifically studying the interaction between rough surfaces and granular flows when the global solid fraction and grain materials are varied. A two dimensional annular (granular) shear cell, with a stationary outer ring and inner driving wheel, was used for this work. Digital particle tracking velocimetry was used to obtain local granular flow data such as velocity, local solid fraction, and granular temperature. Slip between the driving wall and first layer of granules is also extracted. This slip can be interpreted as momentum transfer or traction performance in granular systems such as wheel-terrain interaction. Parametric studies of global solid fraction and the material of the rough driving surface, attempt to show how these parameters affect the local granular flow properties.Copyright © 2009 by ASME
Fast detection based on semi-transient signals in AFM

In this paper, a high-speed width detector is derived for use in atomic force microscopy (AFM). The algorithm rapidly determines the width by detecting the two edges of the sample during a fast scan. The algorithm is designed primarily as a first step towards detection of a single macromolecule moving on a biopolymer. This detector is an important component of a new approach in AFM, a control system that directly tracks the motion of these single macromolecules rather than deriving their motion from a sequence of images. Such an approach promises a much higher temporal resolution than is achievable in time-lapse imaging.
Turbulent Eddy Diffusivity and Mean Eddy Lifetimes Measured in Spray Combuston

Abstract A quantitative description of the eddy structure that occurs in turbulent combustion processes can be obtained by the use of laser velocimetry, as shown in this work. The mean eddy length scales, eddy lifetimes, and turbulent diffusivity have been determined in a spray combustion flame for the first time. Velocity data was obtained at various locations within the flame, and standard correlation techniques were modified and then applied to reduce the data. In order to assess how the spray burns, the measured eddy lifetimes were compared with the relevant reaction times and drop lifetimes. Conditions that are conducive to group combustion of the droplets, rather than individual droplet combustion, were found to exist in the upstream region of the spray. Local measurements of the hydrocarbon concentration also support the conclusion that the majority of droplets undergo group combustion. However, the data indicate that some of the larger drops can survive the initial burning region and form a dilute...
3.1.1 System of Systems Engineering Model by Multistage Analytical Target Cascading

This paper presents a multilevel, multistage approach to system of systems engineering optimization where a system design/selection is linked with system allocation along the multistage decision making horizon. The approach is composed of two parts: pseudo-hierarchical formulation (i.e., how to model the stages of multiple, separate decision making processes), and multistage coordination (i.e., how efficiently the proposed model would perform). The pseudo-hierarchical formulation expands the analytical target cascading previously developed by the author into multiple stages to capture level-by-level and stage-by-stage system of systems design optimization. The multistage coordination is based on the alternating directions method that is incorporated as an efficient means to solve this inherently large-scale optimization problem. An airline example validates the methodology where an airline plans to introduce multiple new aircraft to capture dynamically changing future demand of the customers. The proposed methodology is validated against the all-in-one approach and the sequential approach.
Diffusion and localization in hierarchical potentials.

A simple model of classical relaxation in a one-dimensional harmonic potential with a hierarchical distribution of barriers is studied. The vanishing of an effective diffusion constant results in a transition of the low-lying eigenstates of the master equation from extended to localized. For a parameter characterizing the barrier distribution greater than a critical value Rg${R}_{c}$, the low-lying states are extended on the length scale of the equilibrium distribution. For R${R}_{c}$ the low-lying states are sharply localized at the most difficult barriers to cross. The correlation function 〈x(t)x(0)〉 is analyzed in terms of this eigenstate structure. For Rg${R}_{c}$ correlations are shown to decay as a pure exponential for all times. For R${R}_{c}$, decay is a sum of exponentials which asymptotically approaches the stretched exponential form at long times. Numerical simulations are performed to compute the decay of the correlation functions at shorter times. This decay may also be empirically fitted to a stretched exponential form. The relation of the model to anomalous relaxation in glassy systems is discussed.
Physical therapy workforce in the United States: forecasting nationwide shortages.

Objective To examine current and future physical therapy (PT) job surplus/shortage trends across the United States. Design Forecast models and grading methodology previously published for nursing were used to evaluate individual state PT job shortages from 2008 to 2030. Setting Not applicable. Participants Not applicable. Methods The forecast model used to project PT job supply and demand accounted for changes in age and population size on the basis of estimates from the U.S. Census Bureau for each of the 50 states. PT shortages were assigned letter grades on the basis of shortage ratios (difference between demand and supply per 10,000 people) to evaluate PT shortages and describe the changing PT workforce in each state. Results On the basis of current trends, demand for PT services will outpace the supply of PTs within the United States. Shortages are expected to increase for all 50 states through 2030. By 2030, the number of states receiving below-average grades for their PT shortages will increase from 12 to 48. States in the Northeast are projected to have the smallest shortages, whereas states in the south and west are projected to have the largest shortages. Conclusion These data serve to provide health professionals, policy makers, and stakeholders with a means of assessing current and future PT needs. Discussion of the issues surrounding PT shortages and ongoing assessment of supply and demand must ensue to mitigate projected shortages. Although our model has several limitations and may be oversimplified, it is the first attempt to use available, creditable data to examine both supply and demand for the entire country. Follow-up studies that use more complex modeling are needed to adequately forecast future trends beyond that accomplished in the current article. Monitoring trends over time is critical to maintain an appropriate balance between PT supply and demand that meets the population needs.
ASPERGILLOSIS; REPORT OF TWO INSTANCES IN CHILDREN ASSOCIATED WITH ACUTE LEUKEMIA AND REVIEW OF THE PERTINENT LITERATURE.

Two examples of aspergillosis developing in children with acute leukemia are presented together with a review of the pertinent literature. The increasing incidence of aspergillosis occurring among patients with grave impairment of immunologic defense mechanisms is stressed. The value of early diagnosis is emphasized as new effective agents for the control of aspergillosis are becoming available.
PET positive, PET negative, or PET peeve?

In this issue of Blood , Horning and colleagues report that there was disagreement by 3 nuclear medicine experts on interpretation of FDG-PET images obtained in the context of a clinical trial in aggressive non-Hodgkin lymphoma 32% of the time. 1 These results emphasize the need for standardized criteria to interpret interim PET scans in lymphoma and should cause physicians to question the practice of changing therapy based on PET imaging outside the context of a trial.
Electronic conductivity in Pb(II)-β″ -alumina

Abstract Pb(II)-β″ -alumina is one of several divalent isomorphs of the well-known fast ion conductor, Na(I)-β″ -alumina. When Pb(II)-β″ -alumina is heated in vacuum, it transforms from a colorless electronic insulator toa purple electronic conductor. When heated in air, it returns to the initial state. The electronic conductivity is temperature activated and the color is due to broad but discrete absorptions in the visible range. This paper will discuss the factors that are important to the coloring process, as well as possible mechanisms for the formation of defects and electronic conduction.
Urban Education, the General Education Initiative, and Service Delivery to African-American Students:

Recent reform initiatives have placed the responsibility for effectively educating students with special learning needs in general education. A driving belief of the "general education initiative" is that more students can be effectively served in general classrooms than is currently the case. Two areas (i.e., school climate and parental involvement) that must be discussed if such reform efforts are to make a real difference are presented in this article. Practical suggestions are provided for professionals to consider when embracing questions related to the best and proper place for African-American students with special needs to be educated.
Factors That Drive Peptide Assembly from Native to Amyloid Structures: Experimental and Theoretical Analysis of [Leu-5]-Enkephalin Mutants

Five different mutants of [Leu-5] Enkephalin YGGFL peptide have been investigated for fibril formation propensities. The early oligomer structures have been probed with a combination of ion-mobility mass spectrometry and computational modeling. The two peptides YVIFL and YVVFL form oligomers and amyloid-like fibrils. YVVFV shows an early stage oligomer distribution similar to those of the previous two, but amyloid-like aggregates are less abundant. Atomic resolution X-ray structures of YVVFV show two different modes of interactions at the dry interface between steric zippers and pairs of antiparallel β-sheets, but both are less favorable than the packing motif found in YVVFL. Both YVVFV and YVVFL can form a Class 6 steric zipper. However, in YVVFV, the strands between mating sheets are parallel to each other and in YVVFL they are antiparallel. The overall data highlight the importance of structurally characterizing high order oligomers within oligomerization pathways in studies of nanostructure assembly.
Reversible pulmonary artery obstruction in a patient with bronchogenic carcinoma. Diagnosis by two-dimensional and Doppler echocardiography.

Neoplastic invasion of the pulmonary arteries, although common, rarely results in obstruction to right ventricular outflow. We report an unusual case of severe pulmonary hypertension, right ventricular dilatation, and right ventricular dysfunction resulting from pulmonary arterial compression by bronchogenic carcinoma. The diagnosis was made by two-dimensional and Doppler echocardiography and supported by computed tomographic findings. Echocardiography was used to follow the patient's response to therapy and documented the subsequent resolution of pulmonary arterial obstruction.
Membrane properties of metastatic and non-metastatic cells cultured from C3H mice injected with LM fibroblasts

Abstract Little is known regarding the membrane properties of metastatic cells as compared to non-metastatic tumor cells. In order to remove variables such as site of growth and nutrition. C 3 H mice and LM fibroblasts were used as a model system to derive cell lines from local tumors and lung metastases. LM cells were injected subcutaneously into C 3 H mice and local skin tumors and secondary lung tumors were isolated, cultured in vitro and analyzed. The activities of lipid-sensitive membrane enzymes, membrane lipid composition, and membrane structure were correlated with metastatic ability. Plasma membranes and microsomes of the cultured metastatic cells had 3.8 ± 0.5- and 5.4 ± 0.6-fold elevated 5′-nucleotidase activity, respectively, as compared to plasma membranes and microsomes of cultured non-metastatic cells. The mitochondria of cultured metastatic cells had 3.5 ± 0.5-fold decreased succinate-dependent cytochrome- c reductase activity as compared to mitochondria of the cultured non-metastatic cells. The lipids of plasma membranes from the metastatic cells had 30 ± 2% and 46 ± 7% lower phosphatidylinositol and sterol/phospolipid ratio, respectively, and 30 ± 3% increased unsaturated/saturated fatty acid as compared to cultured non-metastatic cells. The lower sterol/phospholipid ratio correlated with a 30 ± 1% lower level of cytosolic sterol carrie protein in the cultured metastatic cells as compared to cultured non-metastatic cells. Multifrequency phase and modulation fluorometry in conjunction with the fluorescence probe, 1,6-diphenyl-1,3,5-hexatriene, was used to determine the static and dynamic aspects of membrane fluidity. The plasma membranes and microsomes of cultured metastatic cells were more fluid than those of cultured non-metastatic cells as indicated by 24 ± 3% and 7 ± 1%, respectively, lower limiting anisotropy of 1,6-diphenyl-1,3,5-hexatriene in the membranes of the metastatic as compared to non-metastatic cells.
Integrated widely tunable quantum cascade lasers with super-structure gratings

An integrated widely wavelength tunable mid-IR source is demonstrated. This three-section quantum cascade laser consists of a Fabry-Perot section placed between two super-structure grating (SSG) sections. The emission wavelength of the SSG-DBR QCL can be well controlled by varying the injection currents to the two grating sections of the device. The wavelength can be tuned from 4.58 μm to 4.77 μm (90 cm -1 ) with a supermode spacing of 30 nm. The SSG-DBR QCL can be a compact replacement for the external cavity QCL. It has great potential to achieve much further tuning ranges for many mid-IR sensing applications.
An Integrated Creep-Fatigue Theory for Material Damage Modeling

This paper presents an integrated creep-fatigue (ICF) theory to describe the non-linear creep-fatigue interaction during thermomechanical loading. The ICF theory recognizes the damage evolution as a holistic process consisting of nucleation and propagation of surface or subsurface cracks in coalescence with internally distributed damage, leading to final fracture. In a polycrystalline material under combined cyclic and dwell loading, crack nucleation and propagation occurs by fatigue or oxidation mechanisms, whereas internally distributed damage often occurs in the form of grain boundary cavities or microcracks due to creep or dwell effects, particularly at high temperatures. Based on the above mechanism, a damage evolution equation is mathematically derived, and the generality of the above physical mechanisms warrants the applicability of the ICF theory over a wide range of stresses and temperatures. This paper uses Mar-M 509, a cobalt base superalloy, as an example to illustrate how the ICF theory describes creep and low cycle fatigue (LCF).
The Influence of Activity-Based Elementary Science Programs on Classroom Practices: A Quantitative Synthesis.

The results of 11 studies of classroom practices used with the activity-based elementary science programs, ESS, SCIS, and SAPA, were combined quantitatively. All studies included control groups and employed techniques for coding lesson events. A composite category system was developed for combining study results. It was found that teachers using activity-based programs spent about 10% more time on student activity and 10% less time on talk than teachers using traditional methods. More direction giving, more higher level questions, and less lecturing were also reported. Teachers trained in program use spent less time giving directions, more time on activities, and less time on talk than untrained teachers using the programs. On the average, researchers coded slightly less student talk and slightly less student-initiated talk in activity-based classrooms.
Dual-frequency technique for Doppler wind lidar measurements

A variation of the direct detection Doppler Lidar method known as the edge technique is discussed. This new method uses a frequency-agile laser transmitter to alternate the outgoing laser pulse between the two edges of a high resolution Fabry-Perot etalon. The difference in sign of the two slopes of the edge allows the unwanted molecular return signal to be eliminated as a background error source. This technique is similar to that of the 'double-edge' technique, with the main advantage being reduced complexity and cost for the system. By eliminating the error in the wind velocity measurement due to the molecular return, transmitter powers, within the eye-safety range, may be utilized to measure winds within the planetary boundary layer (PBL) with reasonable accuracy for many applications.
Analogy between light scattering of colloidal suspensions and neutron scattering of simple fluids

Abstract The analogy between the line widths of light scattered by colloidal suspensions and neutrons scattered by simple fluids is discussed. Contrary to what is presented in the literature, this analogy - in particular the observed narrowing of the lines - is in both cases related to particle diffusion over intermediate times.
A multifactor approach to student model evaluation

Creating student models for Intelligent Tutoring Systems (ITS) in novel domains is often a difficult task. In this study, we outline a multifactor approach to evaluating models that we developed in order to select an appropriate student model for our medical ITS. The combination of areas under the receiver-operator and precision-recall curves, with residual analysis, proved to be a useful and valid method for model selection. We improved on Bayesian Knowledge Tracing with models that treat help differently from mistakes, model all attempts, differentiate skill classes, and model forgetting. We discuss both the methodology we used and the insights we derived regarding student modeling in this novel domain.
Fluorescence Microscopy Of Lipid Monomolecular Interface Layers

The phase behavior of phospholipid monolayers at a electrolyte/gas interface is studied by fluorescence microscopy. A Wigner lattice is observed at the LE/LC phase transition. Observation are quantified using digital image processing .These results show that the phase transition has three different regimes.
Neuronal, non-neuronal and hybrid forms of enolase in brain: Structural, immunological and functional comparisons

Three forms of the glycolytic enzyme, enolase [2-phospho-D-glycerate hydrolase (E.C. No. 4.2.1.11)] have been prepared from rat whole brain extract. The most acidic enolase form is neuron specific enolase (NSE) which had previously been designated neuron specific protein (NSP). The least acidic form designated non-neuronal enolase (NNE) has been purified and compared structurally, immunologically and functionally to NSE. NNE is a dimer of 86,500 M.W. consistint of two very similar subunits. The data establish that NNE is larger than NSE which has been shown to be composed of two apparently identical 39,000 molecular weight subunits (78,000). NNE is less acidic than NSE having a pI of 5.9 compared to the value of 4.7 for NSE. Structural and immunological analysis establishes that the NNE subunit is distinct from the NSE subunit, and are therfore products of two separate genes. The structural designation of NSE is (gammagamma) and that of NNE (alpha' alpha'). NSE is strictly localized in neurons indicating that the gene coding for the gamma subunit is only expressed in neuronal cells. The intermediate brain enolase form has been partially purified; structural and immunological evidence indicate that it is a hybrid molecule consisting of one NNE subunit and one NSE subunit (alpha'gamma).
Low-Level Expression of miR-375 Correlates with Poor Outcome and Metastasis While Altering the Invasive Properties of Head and Neck Squamous Cell Carcinomas

Small, noncoding microRNAs (miRNAs) have been shown to be abnormally expressed in every tumor type examined. We used comparisons of global miRNA expression profiles of head and neck squamous cell carcinoma (HNSCC) samples and adjacent normal tissue to rank those miRNAs that were most significantly altered in our patient population. Rank Consistency Score analysis revealed miR-375 to have the most significantly lowered miRNA levels in tumors relative to matched adjacent nonmalignant tissue from the same patient among 736 miRNAs that were evaluated. This result has been previously observed by other groups; however, we extend this finding with the unique observation that low miR-375 expression levels correlate significantly with cancer survival and distant metastasis. In a study of 123 primary HNSCC patients using multivariable Cox proportional hazard ratios (HR) and 95% confidence intervals (CI), both death from disease (HR: 12.8, 95% CI: 3 to 49) and incidence of distant metastasis (HR: 8.7, 95% CI: 2 to 31) correlated with lower expression levels of miR-375 regardless of the site or stage of the tumor. In addition, we found that oral cavity tumor cell lines (eg, UMSCC1 and UMSCC47) overexpressing miR-375 were significantly less invasive in vitro than their matched empty vector controls. We conclude that miR-375 represents a potential prognostic marker of poor outcome and metastasis in HNSCC and that it may function by suppressing the tumor's invasive properties.
The structural requirement for C1OH for the active transport of d-mannose and 2-deoxy-d-hexoses by renal tubular cells

Abstract The transport of methyl-α-glycopyranosides of d -mannose, 2-deoxy- d -glucose and 2-deoxy- d -galactose, as well as of 1,5-anhydro-2-deoxy- d -glucitol in slices of rabbit kidney cortex was investigated. 1. 1. In contrast to the respective actively transported hexoses, their methyl-glycopyranosides (0.1–1 mM) were not accumulated in the cells against marked concentration gradients. The entry of the glycosides into the cells was not significantly affected by 0.5 mM ouabain or absence of Na+, and was only slightly inhibited by 0.5 mM phlorizin. 2. 2. The glycopyranosides (5 mM) did not inhibit the active transport of the respective hexoses (1 mM). 3. 3. 1,5-Anhydro-2-deoxy- d -glucitol (0.1–1 mM) was not accumulated in the cells against its concentration gradient, and its entry was not affected by 2-deoxy- d -glucose. Conversely, the active transport of 2-deoxy- d -glucose (1 mM) was not significantly inhibited by a 5-fold molar excess of its 1-deoxy-derivative. 4. 4. It is concluded that, as opposed to the structural requirements for the transport of d -glucose and d -galactose, C1OH is essential for the interaction with the carrier(s) mediating the active transport of d -mannose, 2-deoxy- d -glucose and 2-deoxy- d -galactose.
High-Speed InAs Quantum-Dot Electrooptic Phase Modulators

In this letter, we report results of direct current (dc) and radio-frequency (RF) characteristics of self-assembled InAs quantum-dot (QD) electrooptic modulators. Although dc modulation results have been reported in the literature, these are the first high-frequency designs and measurements. These QD modulator wafers were grown by molecular beam epitaxy (MBE) and phase modulator devices were fabricated with coplanar traveling-wave electrodes. For the 800-μm-long modulators, the half-wave voltage Vπ was measured as 11.4 V at 1.55 μm and 7.34 V at 1.32 μm. The phase variation is 21.9°/(mm·V). The linear electrooptic coefficient T41 is calculated to be 35.4 pm/V for QDs. These modulators have a 3-dB bandwidth of 10 GHz. A signal-to-noise ratio of 9 dB was measured at 20 GHz.
A scheme for high performance real-time BER measurement

A statistically based method of bit error rate (BER) which does not necessitate the transmission of test patterns or the interruption of data for measurement purposes is presented. It is demonstrated that the method allows accurate estimation of BER several orders of magnitude faster than the Monte Carlo method. Design of an optimal BER estimator based on the maximum-likelihood principle is proposed. The performance of the technique is demonstrated by simulations for the case of QPSK modulation in AWGN and for a live Rayleigh-fading HF link. The ability of the method to accurately predict BER using relatively few samples means that it is particularly suitable for high-speed BER estimation. >
In situ simulation: detection of safety threats and teamwork training in a high risk emergency department

Objective Implement and demonstrate feasibility of in situ simulations to identify latent safety threats (LSTs) at a higher rate than lab-based training, and reinforce teamwork training in a paediatric emergency department (ED). Methods Multidisciplinary healthcare providers responded to critical simulated patients in an urban ED during all shifts. Unannounced in situ simulations were limited to 10 min of simulation and 10 min of debriefing, and were video recorded. A standardised debriefing template was used to assess LSTs. The primary outcome measure was the number and type of LSTs identified during the simulations. Secondary measures included: participants’ assessment of impact on patient care and value to participants. Blinded video review using a modified Anaesthetists Non-Technical Skills scale was used to assess team behaviours. Results 218 healthcare providers responded to 90 in situ simulations conducted over 1 year. A total of 73 LSTs were identified; a rate of one every 1.2 simulations performed. In situ simulations were cancelled at a rate of 28% initially, but the cancellation rate decreased as training matured. Examples of threats identified include malfunctioning equipment and knowledge gaps concerning role responsibilities. 78% of participants rated the simulations as extremely valuable or valuable, while only 5% rated the simulation as having little or no value. Of those responding to a postsimulation survey, 77% reported little or no clinical impact. Video recordings did not indicate changes in non-technical skills during this time. Conclusions In situ simulation is a practical method for the detection of LSTs and to reinforce team training behaviours. Embedding in situ simulation as a routine expectation positively affected operations and the safety climate in a high risk clinical setting.
A flow control strategy for ATM networks based on a unified performance parameter

This paper focuses on using source rate adaption (SRA) as a viable flow control scheme. We developed a unified performance parameter, P a function of instantaneous cell loss, buffer occupancy, utilization, and user requirements. The parameter is derived from optimal control theory and is considered useful in quantifying congestion. A SRA strategy for voice services was developed using this parameter. Computer simulations were performed to evaluate the control strategy. It is shown that controlling input rate using SRA based on this parameter is helpful in significantly alleviating congestion and improving the performance. >
Cross-Hedging Fishmeal: Exploring Corn and Soybean Meal Futures Contracts

Soybean meal futures contracts have been shown to be effective cross-hedges for managing fishmeal price risk. Recent supply shocks and growth of aquaculture, poultry, and hog production, where nutrient requirements limit substitution of soybean meal for fishmeal more so than in cattle diets, may be undermining the historical price relationship. Advances in protein content of corn byproducts like corn gluten meal or distiller dried grains suggest corn futures contracts may offer an additional cross-hedging opportunity. We find a composite hedge using both corn futures contracts and soybean meal futures contracts offers superior hedging effectiveness.
Acute stress reaction and completed suicide

BACKGROUND: Acute stress reaction is a diagnosis given immediately following the experience of an exceptional mental or physical stressor. To the best of our knowledge, no study has examined the association between acute stress reaction diagnosis and suicide. The current study examined this association in a population-based sample. In addition, we examined comorbid psychiatric diagnoses as modifiers of this association. METHODS: Data for the current study were obtained from the nationwide Danish health and administrative registries, which include data for all 5.4 million residents of Denmark. All suicides between 1 January 1994 and 31 December 2006 were included and controls were selected from a sample of all Danish residents. Using this nested case-control design, we examined 9612 suicide cases and 199 306 controls matched to cases with respect to gender, date of birth and time. RESULTS: In total, 95 cases (0.99%) and 165 controls (0.08%) had a diagnosis of acute stress reaction. Those diagnosed with acute stress reaction had 10 times the rate of completed suicide compared with those without this diagnosis, adjusting for the control to case matching, depression and marital status (95% confidence interval 7.7-14). Additionally, persons with acute stress reaction and depression, or acute stress reaction and substance abuse, had a greater rate of suicide than expected based on their independent effects. CONCLUSIONS: Acute stress reaction is a risk factor for completed suicide. Language: en
A Popperian perspective of the term 'evidence-based medicine'.

If the term ‘evidence-based medicine’ conveys more than is conveyed by the word medicine, then there must be a way to distinguish between evidence-based medicine and non-evidence-based medicine. In particular, there must be a logically acceptable way to classify medical decisions as justified or unjustified by scientific evidence. In this essay I examine the nature of medical theories, the nature of the evidence that is produced by empirical tests of medical theories, and the relation of medical decisions to both. I conclude that attempts to classify medical decisions as justified or unjustified by scientific evidence have no foundation in logic and that the term ‘evidence-based medicine’ is logically indistinguishable from the term ‘medicine’. The use of the term ‘evidence-based medicine’ calls for a new type of authoritarianism in medical practice.
Decreased β-Cell Function in Overweight Latino Children With Impaired Fasting Glucose

OBJECTIVE —To determine whether overweight Latino children with impaired fasting glucose (IFG) (≥100 mg/dl) have increased insulin resistance or decreased β-cell function compared with those with normal fasting glucose (NFG). RESEARCH DESIGN AND METHODS —We studied 207 healthy overweight Latino children, aged 8–13 years, with a family history of type 2 diabetes. Fasting and 2-h glucose and insulin were assessed by oral glucose tolerance test. Insulin sensitivity ( S i), the acute insulin response to glucose (AIRg), and the disposition index (DI; an index of β-cell function) were determined using the insulin-modified intravenous glucose tolerance test and minimal modeling. Body composition was determined by dual-energy X-ray absorptiometry. RESULTS —There were no differences in body composition between NFG ( n = 182) and IFG ( n = 25) children. Compared with children with NFG, children with IFG had higher fasting and 2-h glucose values and higher fasting insulin. After adjusting for covariates, children with IFG had no difference in S i but 15% lower DI than NFG children (2,224 ± 210 vs. 2,613 ± 76, P < 0.05). Multivariate linear regression showed that AIRg and DI, but not S i, were significant predictors of fasting blood glucose. CONCLUSIONS —In overweight Latino adolescents with a family history of type 2 diabetes, IFG is associated with impaired β-cell function and therefore may identify children likely to be at risk for progression to type 2 diabetes. The actual risk of progression of IFG to type 2 diabetes remains to be determined by prospective longitudinal studies.
The Right not to Incriminate Oneself

The Fifth Amendment to the Constitution of the United States contains the following words: “No person… shall be compelled in any criminal case to be a witness against himself.” In laying down this restriction on what government may do, the Constitution creates a legal right: the right to be free from coercion by any organ of government to testify against oneself – to incriminate oneself.