cssi/SciSciGPT-SciSciNet huggingface dataset:
Spectroscopic imaging with volume selection by unpaired adiabatic π pulses: Theory and application

Abstract In NMR spectroscopy, volume selection can be advantageously achieved using adiabatic π pulses, which enable high bandwidth and B 1 insensitivity. In order to avoid the generation of non-linear phase profiles and the subsequent signal loss caused by incoherent averaging, adiabatic π pulses are usually used in pairs for volume selection in each spatial dimension. Alternatively, when performing spectroscopic imaging (SI), a high enough spatial resolution results in negligible phase dispersion within each pixel. This allows using only one pulse per selected spatial dimension, resulting in a reduced echo-time and reduced power deposition. In this work, the feasibility of such an approach is explored theoretically and numerically, allowing the derivation of explicit conditions to obtain SI images without artifact. Adequate spatial and spectral post-processing procedures are described to compensate for the effect of non-linear phase profiles. These developments are applied to SI in the rat brain at 9.4 T, using a new adiabatic sequence named Pseudo-LASER.
Elderly Persons as Intergenerational Child Care Providers.

Programs involving elderly adults in the provision of child care services have evolved as a possible solution to problems identified by working parents and the elderly.
Cavity tests of parity-odd Lorentz violations in electrodynamics

Electromagnetic resonant cavities form the basis for a number modern tests of Lorentz invariance. The geometry of most of these experiments implies unsuppressed sensitivities to parity-even Lorentz violations only. Parity-odd violations typically enter through suppressed boost effects, causing a reduction in sensitivity by roughly 4 orders of magnitude. Here we discuss possible techniques for achieving unsuppressed sensitivities to parity-odd violations using asymmetric resonators.
Characterization and modeling of the magnetic field-induced strain and work output in Ni2MnGa magnetic shape memory alloys

Abstract This paper is concerned with the experimental characterization and the constitutive modeling of magnetic shape memory alloys (MSMA), in terms of their applicability as actuator materials. The key properties that determine the actuation characteristics are the magnetic field-induced strain (MFIS) and the blocking stress. With the goal of increasing the corresponding actuation output, a material selection strategy was followed which was aimed at obtaining a higher magnetocrystalline anisotropy energy, while keeping the detwinning stress low. This was achieved by choosing a composition in which the separation of the Curie temperature and the martensitic transformation temperatures was large, and then selecting an operating temperature just below the phase transformation temperature. In the selected Ni 51.1 Mn 24.0 Ga 24.9 composition a more than 50% increase of the actuation work output was observed, compared to corresponding data reported in the literature for other off-stoichiometric compositions of the Ni 2 MnGa intermetallic compound. The second part of the paper describes a phenomenological constitutive model that predicts the MFIS hysteresis curves observed in the first part. The model is concerned with the field-induced reorientation of martensitic variants and changes in the magnetic microstructure. Dissipative effects are captured by introducing internal state variables into the free energy function. In its most general form the contributing energy terms are the elastic strain energy, the Zeeman energy, the magnetocrystalline anisotropy energy and appropriate mixing terms. Typical loading cases are considered and the accuracy of the model predictions is evaluated by comparison with the experimental data presented in the first part of this work.
Charge Transport in Spatially-Disordered Dipolar Media

High field charge transport in molecularly-doped polymers and amorphous molecular glasses occurs through the hopping motion of photoexcited carriers among localized molecular transport sites characterized by considerable energetic and spatial disorder. A large number of numerical simulations of this process have been performed using models in which transport sties are located on the sties of a regular lattice, with spatial disorder included in a phenomenological fashion. We present calculations that explore drawbacks of this approach, and present arguments to show that the magnitude of the energetic disorder assumed. In particular, we show using a simple model of randomly- placed transport sites with no underlying lattice that such analyses have the potential for attributing to the energetic disorder an artificial dependence on dopant density similar to that reported in the experimental literature.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Letter to the Editor-Implementation of New Ideas in Bureaucracies

This note speculates that, in a large bureaucracy, the probability of implementing new ideas depends on the number of persons in the chain leading to the implementation. Some possible organizational consequences are mentioned.
A heteroscedasticity-consistent covariance matrix estimator for time series regressions

Abstract This paper provides a covariance matrix estimator for the ordinary least squares coefficients of a linear time series model which is consistent even when the disturbances are heteroscedastic. This estimator does not require a formal model of the heteroscedasticity. One can also obtain a direct test of heteroscedasticity, although Monte Carlo experiments show that it may have low power.
Explicit numerical formulas of improved stability and accuracy for the solution of parabolic equations

A class of explicit numerical formulas which involve next nearest neighbor as well as nearest neighbor points are explored in this paper. These formulas are formal approximations to the linear parabolic partial-differential equation of first order in time and second order in distance. It was found that some of these formulas can employ time steps as much as four times that for the conventional explicit technique without becoming unstable. Others showed improved accuracy for a given time step and spatial grid spacing. One formula achieved a steady-state solution of specified accuracy for an example problem in less than 4 percent of the total computational time required by the conventional explicit technique.
Crystal Structure of a Porous Zirconium Phosphate/Phosphonate Compound and Photocatalytic Hydrogen Production from Related Materials

The preparation, structure, and catalytic properties of porous zirconium phosphate/phosphonate compounds are discussed. The crystal structure for the Zr2(PO4)(O3PCH2CH2(viologen)CH2CH2PO3)X3·3H2O, X = halide, is presented. The structure was determined ab initio from X-ray powder diffraction data and refined by Rietveld methods. The compound crystallizes with the symmetry of space group P2/c with a = 13.589(2) A, b = 8.8351(9) A, c = 9.229(1) A, and β = 100.79°. The structure consists of inorganic lamellae bridged by phosphono−ethyl−viologen groups. Large pores are formed in this material, which contain one halide ion and three water molecules per formula unit. The free halide ions in these materials are readily exchanged for PtCl42- ions. The Pt salt was reduced to give fine metal particles inside the porous solid. These materials produce hydrogen photochemically from water using ultraviolet light. The average rate of H2 production is 0.15 mL/h with a lower limit quantum yield of 4% based only on the ultr...
Birth intervals and early childhood mortality in a migrating Mennonite community

This study explores the significance of birth spacing with regard to neonatal postneonatal and early childhood mortality among rural Mennonites belonging to one congregation in Russia and one in Kansas. Analysis is based on the two causal mechanisms: maternal depletion and sibling competition. Respondents comprised a total of 930 and 1484 births in Russia and Kansas respectively by 381 mothers obtained from the vital events of families reconstructed from church records. In general the multivariate analyses are consistent with the bivariate analyses and further clarify the interrelationships that 1) the subsequent interval seems to explain more of the variance than the previous interval at least in most settings; 2) maternal age is the statistically significant covariate rather than birth order or parity. These and other observations may provide at least tentative support for the action of both mechanisms: maternal depletion and sibling competition (and disease). Other evidences were discussed extensively.
Interpreting the present to ensure a future: an interview of financial success at the Fairfax County Public Library

In order to remain viable, the Fairfax County Public Library has re‐examined itself and changed its attitudes toward funding and fund‐raising. Stemming from serious cutbacks due to the poor economy of the early 1990s, the Library changed the way it did business. The programs instituted have permitted the Library to provide better service, increase the Library’s importance to the County, and enhance the budget through public and corporate donations. One of these programs is a Library Foundation. Fairfax County Public Library is one of the few public library systems in the country that has moved into this arena of fund‐raising. This case study involves the current library director and the past chairman of the Library Board, as they relate issues pertinent to these initiatives and indicate the direction in which the Library may head in the future.
Enhancement of film condensation rate on vertical tubes by longitudinal fins

Longitudinal rectangular fins loosely clamped to vertical tubes markedly increase the film condensation heat transfer coefficient. At a heat flux of 2×104 B.t.u./hr.sq.ft., twelve ⅛×0.013 fins clamped to a ½ in. O.D. vertical tube 42 ½ in. long (thus doubling the surface area of the tube) gave a condensation coefficient of 15,000 ± 15% B.t.u./hr.sq.ft. °F. compared with 1,620 B.t.u./hr.sq.ft. °F. for the same tube without fins, a ratio of h/ho of 9.2. The enhancement of the film condensation coefficient decreases as the heat flux increases and as the number of fins decreases. A model based on the effect of fin shape on film and rivulet hydrodynamics explains the observed behavior.
Analysis of neuronal networks: a review of techniques for labeling axonal projections.

In order to analyze connections between neurons in the vetebrate central nervous system, methods have been developed to label a given population of axons of known origin so that they can be differentiated from other, non-labeled structures. Three such methods are reviewed here: experimentally induced orthograde (Wallerian) degeneration, axon transport of radioactive proteins demonstrated by autoradiography, and axon transport of macromolecules that can be reacted histochemically to yield a visible reaction product. Each of the methods has particular strengths and weaknesses. Degeneration methods may differentiate between different functional classes of axons which have different fiber diameters. However, degeneration distorts the morphology of axon terminals, making them more difficult to interpret, and degenerating terminals may be removed rapidly by phagocytosis. Autoradiography of radioactive terminals preserves normal fine structure, but the necessary exposure times extend the method by weeks or months, and care must be exercised to distinguish labeled axons from other structures exhibiting background or transneuronal radioactivity. Histochemical methods, such as those used to demonstrate horseradish peroxidase conjugated to wheat germ lectin (WGA-HRP), are sensitive and rapid, but the injection site must be carefully characterized, and the presence of transneuronal label may make interpretation of the results difficult. Experimental methods of axonal labeling have been invaluable in studying neuronal networks. Each of the methods described here may be of particular value, given the nature of the system to be analyzed.
Fission Product Yields from Fission Spectrum n+ 239 Pu for ENDF/B-VII.1

We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small - especially for {sup 99}Mo - we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for {sup 95}Zr, {sup 140}Ba, {sup 144}Ce), but are larger for {sup 99}Momore » (4%-relative) and {sup 147}Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the {sup 147}Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on the energy dependence over the fast neutron energy range from 0.2-2 MeV. Based on these trends, we present an evaluation of the FPY data at 0.5 and 2.0 MeV average incident neutron energies. This new set of ENDF/B-VII data will enable users to linearly interpolate between the pooled FPY data at {approx}0.5 MeV and our new data at 2 MeV to obtain FPYs at other energies.« less
Qualitative differences between Shuttle on-orbit and transition control

Two separate reaction control system digital autopilots evolved from one original Space Shuttle orbital autopilot concept. A computer overload forced this evolution. Part of the overload problem was due to unique performance requirements imposed on the reaction control system during each of several different flight regimes. The two resultant reaction control system digital autopilots yield different effector responses because they rely on different sources of sensory input and they process data differently. This paper describes the evolution of the two and illustrates their behavioral differences. The transition autopilot, used in orbital insertion and deorbit, is sensitive to Orbiter flexure due to its feedthrough character. The on-orbit autopilot is sensitive to transient rate control degradation from large disturbances due to feed-forward rate estimation. Simulation results and flight data are used to illustrate performance differences between the two autopilots under various conditions. These include computer failures where electronic stringing and procedural reconfiguration differences affect autopilot behavior.
New resources for the forensic genetics community available on the NIST STRBase website

Abstract For more than a decade, the U.S. National Institute of Standards and Technology (NIST) has maintained the short tandem repeat DNA Internet database (STRBase), which is located at http://www.cstl.nist.gov/biotech/strbase/. The purpose of STRBase has been and continues to be an attempt to bring together the abundant literature and information in the forensic genetics field in a cohesive fashion to make current and future work easier. New materials are regularly added to expand the valuable information contained on the STRBase website.
Collaborative creation of a lab rubric.

While there are a number of tested rubrics in circulation, our task was to intervene in a particular situation: the lead professor was concerned because her graduate teaching assistants held negative views about student performance on the lab reports. GTAs found poor products frustrating, and admitted that their grading was thus superficial and provided no feedback to students. Specifically, GTAs did not feel equipped to evaluate writing and, as a result, simply graded on steps completed in the lab process. We have a rubric now for an Introduction to Zoology lab that could be submitted here as a pretty darn good rubric for other instructors to use. But the intent of our “Tips and Tools” is to describe the actual creation of the rubric. We believe the active “real time” development of the rubric carried as much or more value than the finished product.
The Location of Power Line TYI: Some Reduction Considerations

An oscilloscope method for locating power line television interference is described. The method has several advantages over the use of meter readings, including that of discrimination between noise sources when several are present. Practical information is given regarding equipment requirements and use. Observed noise-pulse patterns are illustrated by photographs. TVI reduction by means of correction and prevention is discussed. TVI can result from corona-precipitation impingement on EHV lines and is an important consideration.
S2-4 H2S and mitochondrial division/mitophagy inhibitor (MDIVI-1) protect right ventricle from severe heart failure

Chronic heart failure is common form of cardiovascular disease and is a leading cause of morbidity and mortality worldwide. Sustained pressure–volume overload induces pathological cardiac abnormalities, linked to mitochondrial dysfunction during right ventricular failure (RVF). In this study we tested the hypothesis that whether the mitochondrial division inhibitor (Mdivi-1) mitigates oxidative stress and in turn reverses the RV dilatation and dysfunction that occurs with chronic RV pressure–volume overloaded. We subjected pulmonary artery constriction (PAC) for 4 weeks in three (3) strains of mice (C57, FVB, and C3H), each with increasing resistance to oxidative stress. After surgery each strain was treated with Mdivi-1 (50 mg/kg/day) or the DMSO vehicle. After PAC, mice developed increased cardiac mass, lower wall thickness, more oxidative stress and mitochondrial dysfunction. The Mdivi-1 treatment reversed RV dilatation and fibrosis, lowered oxidative stress and improved chamber function. Treatment also abolished the PAC-induced increase in LC3-A/B and p62 levels that was associated with PAC-induced increases in blood flow velocity (BFV). We conclude that Mdivi-1 treatment results in protection of RVF by mitigating mitophagy during pulmonary arterial hypertension. We suggest that inhibition of mitochondrial fission during RV dysfunction results in amelioration of RVF and this is accomplished by inhibiting abnormal autophagy/mitophagy and fibrosis during pulmonary arterial hypertension (PAH).
7,7-Dimethyl-7-siladispiro[2.0.2.1]heptane derivatives. The first silacyclopropanes

Abstract The preparation of the first silacyclopropanes, all derivatives of 7,7-dimethyl-7-siladispiro[2.0.2.1]heptane, by magnesium-induced ring closure reactions of 1,3-dihalides, is described. Mass spectral and 1 H, 13 C and 29 Si NMR spectral data, as well as the unusually high chemical reactivity of these compounds support the assigned silacyclopropane structures.
A Structure for Easy Fish Recovery during Drainage of an Impoundment

(1965). A Structure for Easy Fish Recovery during Drainage of an Impoundment. The Progressive Fish-Culturist: Vol. 27, No. 4, pp. 237-238.
RtcB, a Novel RNA Ligase, Can Catalyze tRNA Splicing and HAC1 mRNA Splicing in Vivo

RtcB enzymes are novel RNA ligases that join 2',3'-cyclic phosphate and 5'-OH ends. The phylogenetic distribution of RtcB points to its candidacy as a tRNA splicing/repair enzyme. Here we show that Escherichia coli RtcB is competent and sufficient for tRNA splicing in vivo by virtue of its ability to complement growth of yeast cells that lack the endogenous "healing/sealing-type" tRNA ligase Trl1. RtcB also protects yeast trl1Δ cells against a fungal ribotoxin that incises the anticodon loop of cellular tRNAs. Moreover, RtcB can replace Trl1 as the catalyst of HAC1 mRNA splicing during the unfolded protein response. Thus, RtcB is a bona fide RNA repair enzyme with broad physiological actions. Biochemical analysis of RtcB highlights the uniqueness of its active site and catalytic mechanism. Our findings draw attention to tRNA ligase as a promising drug target.
Prediction of Functional Status for the Elderly Based on a New Ordinal Regression Model

The functional mobility of the elderly is a very important factor in aging research, and prognostic information is valuable in making clinical and health care policy decisions. We develop a predictive model for the functional status of the elderly based on data from the Second Longitudinal Study of Aging (LSOA II). The functional status is an ordinal response variable. The ordered probit model has been moderately successful in analyzing such data; however, its reliance on the normal distribution for its latent variable hinders its accuracy and potential. In this paper, we focus on the prediction of conditional quantiles of the functional status based on a more general transformation model. The proposed estimation procedure does not rely on any parametric specification of the conditional distribution functions, aiming to reduce model misspecification errors in the prediction. Cross-validation within the LSOA II data shows that our prediction intervals are more informative than those from the ordered probit...
Design of a single-stage mechanical fat separator

Thermal fractionation of highly saturated fats can address the current nutritional concerns related to the amount, type, and saturated-fat level of lipids in foods. Separation of fats into different melting fractions allows for tailoring natural fats into functional and nutritional groups, while also allowing for the use of the less desirable fractions in nonfood applications. The single-stage laboratory-scale separator described herein separates fats into two gross melting fractions, termed high and low. The latter fractions can be further separated by adjusting the cooling zone temperatures, resulting in secondary fractions with different melt patterns. Thermal analysis of the hard fractions shows a 10–15°C shift to a higher melting point.
Two self-rating scales for depression in Hmong refugees: assessment in clinical and nonclinical samples

Abstract An exploratory cross-cultural study was undertaken of two widely used self-rating scales: the Zung and the Depression Scale on the 90 Item Symptom Checklist, or SCL-Depression. Both scales were translated into Hmong and tested in two samples of Hmong refugees in the U.S.A. One sample ( n =86) consisted of a field survey of all Hmong people living in Minnesota. Of the 86, 15 sought treatment and were diagnosed as having major depression during the year following their self rating, so that a comparison of patients' scores with nonpatients' scores was possible. The other sample consisted of another 51 Hmong psychiatric patients with major depression. This second group was also assessed by four psychiatric rating scales (i.e. Hamilton Depression Scale, brief Psychiatric Rating Scale, Inpatient Multidimensional Rating Scale, and Nurse's Observation Scale for Inpatient Evaluation) and two measures of treatment intensity (i.e. number of visits, duration of treatment). In the general Hmong population ( n =86), both self-rating scales were highly intercorrelated, and strongly associated with patient status. In the patient sample ( n =51), only the SCL-Depression showed any correlations with psychiatric rating scales or with treatment variables. This is contrary to the anticipated outcome, as it had been expected that the Zung would perform better than the SCL-Depression. In addition, duration of treatment was inversely correlated with the SCL-Depression, also opposite to our prediction. Probable causes for these unexpected results are presented. An item analysis was undertaken, comparing 71 Hmong survey subjects who were not treated for depression with 51 Hmong psychiatric patients who were treated for depression. Most Zung and SCL-Depression items showed significantly higher symptom levels in the depressed patients. However, non-depressed controls unexpectedly reported significantly higher symptom levels on certain items. No significant differences were observed on several Zung and SCL items. These unexpected findings are discussed in light of the refugee's adjustment and experience.
Study on the Nonlinear Characteristic of a Rotor-Bearing System between the Continuum Model and Discrete Model

The nonlinear dynamic behavior of a rotor-bearing system is analyzed with its finite element model based on the analysis of the discrete model, with considering some other important influencing factors such as, material damping, gyroscopic effect, inertia distribution, shear effect and so on, which make the description of the system more embodiment avoiding the casualness of selection with system parameters. With the comparison of the results on the bifurcation map and three-dimensional spectrum, significant difference is appeared with the addition of the considered factors. It is suggested that the substitution of continuum model for the discrete ones can get more accurate and abundant results. Furthermore, these results can provide more accurate verification and reference for the experiment and nonlinear dynamic design of the complex rotor system.
Social Security in the 21st Century

The Social Security program is now 75 years old and debate and reform are in the air. Some decry that its benefits are inadequate and should be improved, especially for lifetime low earners, women and minorities. Others, more loudly, proclaim that the system is in financial difficulty and, if nothing is done, will soon go broke. As a result of the last major amendments enacted in 1983, Social Security trust funds now have reserves of $2.5 trillion, at least on paper. However, the trust funds are an accounting device. There is no real money there. It has been spent by the Treasury to fund other government programs and has served to mask a significant portion of the federal deficit for the past 25 years. The Social Security problem is really a federal fiscal problem. The U.S. Treasury owes the Social Security Administration a great deal of money, and the bill is about to become due. In 2010, for the first time in decades, Old Age, Survivor and Disability Insurance expenditures are greater than Federal Insur...
Theoretical surface temperatures generated from sliding contact of pure metallic elements

Abstract Surface temperatures and thermal effects produced in tribological processes are important not only in influencing possible mechanisms of friction, wear, and lubricant film failure but also in initiating protective film-formation. As part of a continuing combined theoretical and experimental study of surface temperatures generated by friction, the fundamental Green's function approach has been applied to a number of pure metallic elements to compare and discuss their predicted behavior in A-on-A sliding contact. Assuming a single area of real contact, calculated ratios of surface temperature rise to coefficient of friction plotted against area of contact, velocity and load on a logarithmic scale are presented and summarized for several pure metallic elements in the first transition series of the Periodic Table (e.g., Ti, V, Cr, Mn, Fe, Co, Ni) as well as members in connecting groups, e.g., Cr, Mo, and W in Group VIa and Cu, Ag, and Au in Group Ib. These include metals which are tribologically difficult to machine and use (e.g., Ti), common elements in bearing steels (e.g., Fe, Cr), and metals useful in reducing friction or wear when applied as thin surface coatings (e.g., Ag, Au). The results of this comparison are interesting and surprising. They may add to our understanding of why some metals are very “difficult” in a tribological sense while others provide benefits in controlling friction and/or wear.
Macroporous hydrogel micropillars for quantifying Met kinase activity in cancer cell lysates

Overactive and overexpressed kinases have been implicated in the cause and progression of many cancers. Kinase inhibitors offer a targeted approach for treating cancers associated with increased or deregulated kinase activity. Often, however, cancer cells exhibit initial resistance to these inhibitors or evolve to develop resistance during treatment. Additionally, cancers of any one tissue type are typically heterogeneous in their oncogenesis mechanisms, and thus diagnosis of a particular type of cancer does not necessarily provide insight into what kinase therapies may be effective. For example, while some lung cancer cells that overexpress the epidermal growth factor receptor (EFGR) respond to treatment with EGFR kinase inhibitors, overexpression or hyperactivity of Met kinase correlates with resistance to EGFR kinase inhibitors. Here we describe a microfluidic-based assay for quantifying Met kinase activity in cancer cell lysates with the eventual goals of predicting cancer cell responsiveness to kinase inhibitors and monitoring development of resistance to these inhibitors. In this assay, we immobilized a phosphorylation substrate for Met kinase into macroporous hydrogel micropillars. We then exposed the micropillars to a cancer cell lysate and detected substrate phosphorylation using a fluorescently conjugated antibody. This assay is able to quantify Met kinase activity in whole cell lysate from as few as 150 cancer cells. It can also detect cells expressing overactive Met kinase in a background of up to 75% non-cancerous cells. Additionally, the assay can quantify kinase inhibition by the Met-specific kinase inhibitors SU11274 and PHA665752, suggesting predictive capability for cellular response to kinase inhibitors.
Failure mechanism analysis and process improvement on time-dependent dielectric breakdown of Cu/ultra-low-k dielectric based on complementary Raman and FTIR spectroscopy study

Time-dependent dielectric breakdown (TDDB) is one of the most important reliability issues in Cu/low-k technology development. With continuous technology scaling to nanometer scale, TDDB issue is further exacerbated. In this paper, two failure mechanisms were investigated: the Ta ions migration model and the line-edge-roughness (LER) model, which is rendering the observed TDDB failure. Complimentary Raman and FTIR spectroscopy were applied to investigate the dielectric bonding characteristics. Our experimental results revealed the TDDB degradation behavior of Cu/ultra-low-k interconnects, suggesting the intrinsic degradation of the ultra-low-k dielectric. No out-diffusion of Cu ions was observed in Cu/Ta/TaN/SiCOH structures. Extensive TEM analysis further verified the migration of Ta ions from the Ta/TaN barrier bi-layer into the ultra-low-k dielectrics. Based on the LER model analysis, a comparative study in both passing and failing die elaborates that the slopped trench/via profile affected the TDDB performance.
THE EFFICIENCY OF THE HIGH-TECH ECONOMY: CONVENTIONAL DEVELOPMENT INDEXES VERSUS A PERFORMANCE INDEX*

ABSTRACT. Data Envelopment Analysis (DEA) is employed to construct an index ofrelative efficiencies by maximizing two proxies of high-tech output subject to minimiz-ing five specific resources often associated with high-tech infrastructure. This approachranks the 50 U.S. states from the most robustly efficient to the most robustly inefficient.The DEA approach avoids using equal or subjective weights employed in the New StateEconomyIndexrankings.Therankingofthe50statesyieldssomeinterestingdifferencesbetween some states’ dominance in high-tech industries and their economic performance. 1. INTRODUCTIONNew communication technology through the use of personal computersand the Internet has become the means of assisting production, commerce, andbusiness services for most of the modern world. As the new economy began toflourish in the late 1990s, there appeared significant interest among analystsin determining which areas had high-tech concentrations, and what productspecializations were occurring within each of these metropolitan areas (DeVol,1999; Cortright and Meyer, 2001). Researchers wanted to identify a compara-ble set of high-tech measures for a particular set of comparable metropolitanregions (Great North Alliance, 2001; Markuson, 2004).Often single measures or more aggregated indexes of rankings of specificgeographical entities such as cities, states, or regions, established the extent
Teaching signal processing according to what your students know

Many professors and instructors fear (or rejoice) that the Internet will someday make their role as teacher obsolete. While the Internet is an incredible repository of knowledge, it is not a repository of experience. In this paper, I present how instructors can leverage the information on the Internet to empower themselves to apply their experience to better teach students according to what their students know. This interplay can increase learning, student engagement, and create new ways to assess the quality of teaching.
Descendants of Totoliguoqui: Ethnicity and Economics in the Mayo Valley

Descendants of Totoliguoqui: Ethnicity and Economics in the Mayo Valley. Mary I. O'Connor. University of California Publications in Anthropology, volume 19. Berkeley: University of California Press, 1989. 143 pages, plates and bibliography. $15.50 (paper). ISBN 0–520–09742–4.
Absence of Glucagon and Insulin Action Reveals a Role for the GLP-1 Receptor in Endogenous Glucose Production

The absence of insulin results in oscillating hyperglycemia and ketoacidosis in type 1 diabetes. Remarkably, mice genetically deficient in the glucagon receptor (Gcgr) are refractory to the pathophysiological symptoms of insulin deficiency, and therefore, studies interrogating this unique model may uncover metabolic regulatory mechanisms that are independent of insulin. A significant feature of Gcgr-null mice is the high circulating concentrations of GLP-1. Hence, the objective of this report was to investigate potential noninsulinotropic roles of GLP-1 in mice where GCGR signaling is inactivated. For these studies, pancreatic β-cells were chemically destroyed by streptozotocin (STZ) in Gcgr(-/-):Glp-1r(-/-) mice and in Glp-1r(-/-) animals that were subsequently treated with a high-affinity GCGR antagonist antibody that recapitulates the physiological state of Gcgr ablation. Loss of GLP-1 action substantially worsened nonfasting glucose concentrations and glucose tolerance in mice deficient in, and undergoing pharmacological inhibition of, the GCGR. Further, lack of the Glp-1r in STZ-treated Gcgr(-/-) mice elevated rates of endogenous glucose production, likely accounting for the differences in glucose homeostasis. These results support the emerging hypothesis that non-β-cell actions of GLP-1 analogs may improve metabolic control in patients with insulinopenic diabetes.
Clinical trial designs for predictive biomarker validation: Theoretical considerations and practical challenges

Purpose Biomarkers can add substantial value to current medical practice by providing an integrated approach to prediction using the genetic makeup of the tumor and the genotype of the patient to guide patient-specific treatment selection. We discuss and evaluate various clinical trial designs for the validation of biomarker-guided therapy. Methods Designs for predictive marker validation are broadly classified as retrospective (ie, using data from previously well-conducted randomized controlled trials [RCTs]) versus prospective (enrichment, unselected, hybrid, or adaptive analysis). We discuss the salient features of each design in the context of real trials. Results Well-designed retrospective analysis from well-conducted prospective RCTs can bring forward effective treatments to marker-defined subgroups of patients in a timely manner (eg, KRAS and colorectal cancer). Enrichment designs are appropriate when preliminary evidence suggest that patients with or without that marker profile do not benefit from the treatments in question; however, this may sometimes leave questions unanswered (eg, trastuzumab and breast cancer). An unselected design is optimal where preliminary evidence regarding treatment benefit and assay reproducibility is uncertain (eg, epidermal growth factor receptor and lung cancer). Hybrid designs are appropriate when preliminary evidence demonstrate the efficacy of certain treatments for a marker-defined subgroup, making it unethical to randomly assign patients with that marker status to other treatments (eg, multigene assay and breast cancer). Adaptive analysis designs allow for prespecified marker-defined subgroup analyses of data from an RCT. Conclusion The implementation of these design strategies will lead to a more rapid clinical validation of biomarker-guided therapy.
An optimal investment strategy model for fiber to the home

Planning for the deployment of fiber to the home is made particularly difficult by rapidly changing network component costs and a multitude of system architecture alternatives. A modeling approach using dynamic programming to select an optimal investment strategy for rehabilitating existing copper plant with fiber to the home is described. The optimal time to invest is determined by a simple tradeoff: early deployment allows the carrier to receive additional revenues from video services more quickly; later deployment can be accomplished with less costly technology. Given the assumptions of the model about component cost trends and demand forecasts, and in the absence of competition, the model predicts that discounted profits to a local exchange carrier (LEC) are maximized by deferring investment in fiber to the home until well into the 21st century. The results are particularly sensitive to a few system parameters: the assumed rate of subscriber growth in broadband services, the cost of optical components, and the cost of network maintenance. Some policy implications of the study are examined. >
Beltsville Poultry Semen Extender. 8. Factors Affecting Turkey Semen Held Six Hours at 15 C

Abstract Several experiments were conducted to measure the effects of extender pH, size and type of storage vessel, insemination dose volume, and frequency of insemination on the motility and fertilizing capacity of turkey semen held 6 hr at 15 C. The fertilizing capacity and motility of both unstored and stored turkey sperm were depressed more when diluted in Beltsville Poultry Semen Extender at pH 5.5 than at pH 6.5 or 6.0. The fertility of stored semen was impaired when agitated for 6 hr regardless of the type of storage vessel used. Sperm motility was higher when semen was held in flasks than when held in tubes. There were no differences in fertility of hens inseminated with .025, .05, or .10 cm3 of either unstored or stored semen during the first 10 weeks of egg production. However, fertility differences between unstored and stored semen were noted with all insemination doses late in the production period. Hens inseminated every 7 days with unstored semen maintained a constant level of fertility (+90%) for the 20-week production period, whereas the fertility of hens inseminate d at 10- or 14-day intervals was lower in Weeks 11 to 20. Regardless of insemination interval, fertility of stored semen was lower than fertility of unstored semen in the latter stages of egg production.
Modulation of deprivation-induced food intake by d-phenylalanine

D-phenylalanine has been shown to possess opiate-like effects upon pain perception. The present study examined whether it would have similar opiate-like effects upon food intake in deprived rats. The first experiment demonstrated that food intake of rats deprived for 24 h prior to injection was significantly reduced for 2 h following a 250 mg/kg dose of D-phenylalanine. However, intake over a 24 h period following injection was significantly increased following a 125 mg/kg dose of D-phenylalanine. The second experiment revealed that 0.3, 1.0, 3.0 and 10.0 mg/kg doses of naloxone dose-dependently reduced intake for 2 h in deprived rats when paired with a vehicle injection. However, the inhibitory actions of the two lower naloxone doses were significantly attenuated when paired with an injection of a 250 mg/kg dose of D-phenylalanine. These results are discussed in terms of whether D-phenylalanine possesses direct or indirect opiate-like effects upon ingestion.
Muscle forces during locomotion in kangaroo rats: force platform and tendon buckle measurements compared.

The muscle forces and stresses occurring during normal locomotor activity in kangaroo rats are compared with the peak isometric force developed by the same muscles in situ. Two methods were used simultaneously to determine the stresses (force/cross-sectional area) acting in the ankle extensors during steady-speed hopping and during jumps when animals were startled: a direct measurement using a force buckle surgically implanted around a tendon; and an indirect measurement using a force platform/cine analysis technique. We obtained essentially the same values with the two techniques. We found that at slow speeds (0.7 m s-1) the ankle extensor muscles of kangaroo rats exerted 20% of the maximum isometric force developed when the muscles were stimulated via the tibial nerve. This increased to 53% at higher speeds (1.9 m s-1). At the animals's preferred hopping speed (1.5 m s-1), peak force was approximately 40% of maximum isometric force. In jumps when animals were startled, peak forces as high as 175% of the maximal elicited isometric force were recorded. These high forces always occurred when the muscles were being stretched. It appears that kangaroo rats utilize nearly the entire range of muscle force possible during normal locomotor events (i.e. up to 175% of maximum isometric force when muscles are stretched).
A generalized Forney formula for algebraic-geometric codes

This correspondence contains a straightforward generalization of decoding of BCH codes to the decoding of algebraic-geometric codes, couched in terms of varieties, ideals, and Grobner bases. This consists of 1) a Berlekamp-Massey-type lattice-shifting row-reduction algorithm with majority voting similar to algorithms in the current literature, 2) a realization that it produces a minimal Grobner basis B for the error-locator ideal I(V) relative to a particular weighted total degree monomial ordering, 3) a factoring of that basis into several minimal PLEX bases, that facilitates finding the variety V of error positions, and 4) a direct generalization of Forney's formula to calculate error magnitudes using functions /spl sigma/p, which are by-products of this factoring.
DETERMINATION OF ULTRASONIC-BASED RHEOLOGICAL PROPERTIES OF DOUGH DURING FERMENTATION'

An ultrasonic technique was used to study the changes of the rheological properties of dough during fermentation at 37C and compared with the extensional properties of fermented dough obtained from tensile tests carried out in a Universal Testing Maching. The velocity and attenuation of a longitudinal wave (P-wave) propagated through the dough samples were measured and analyzed to obtain the viscoelastic moduli of the dough; the storage modulus M' and the loss modulus M''. These moduli include both the bulk and the shear moduli. A wavelet analysis also was used to determine the effect of frequency on the ultrasonic-based viscoelastic moduli and the effect of the fermentation process on the ultrasonic velocity dispersion. A decrease in ultrasonic velocity was observed with increasing fermentation times. Ultrasonic waves were strongly attenuated in the dough subjected to long fermentation times and fermentation had a large influence on the viscoelastic moduli of the dough. The ultrasonic velocity increased with increasing frequency, clearly showing the viscoelastic nature of the fermented dough. The analysis also showed significant ultrasonic velocity dispersion upon fermentation. Ultrasonic measurements yielded results that agreed with those obtained from conventional rheology commonly used to characterize the extensional properties of dough. Both tests clearly showed the loss of elasticity by the dough samples upon fermentation.
Predictable Periimplant Gingival Esthetics: Use of the Natural Tooth as a Provisional following Implant Placement

UNLABELLED Maintaining the interdental papilla and bone height following implant placement has been a challenge for the restorative dentist. Bone resorption following anterior tooth extraction is common and often compromises the esthetics of the final restoration. The tissue must be maintained during the surgical and healing phases to achieve an esthetic outcome. Using the patient's natural tooth as a provisional can help maintain the volume and support the papilla. This article describes a technique to achieve maximum esthetics and preservation of tissue following tooth extraction and implant placement. CLINICAL SIGNIFICANCE By using the patient's extracted natural tooth, the tissue should maintain itself with minimal recession. This will allow for a more esthetic outcome.
Changes in dihydrofolate reductase (DHFR) mRNA levels can account fully for changes in DHFR synthesis rates during terminal differentiation in a highly amplified myogenic cell line.

Abstract Dihydrofolate reductase (DHFR) enzyme is preferentially synthesized in proliferative cells. A mouse muscle cell line resistant to 300 microM methotrexate was developed to investigate the molecular levels at which DHFR is down-regulated during myogenic withdrawal from the cell cycle. H- alpha R300T cells contained 540 copies of the endogenous DHFR gene and overexpressed DHFR mRNA and DHFR protein. Despite DHFR gene amplification, the cells remained diploid. As H- alpha R300T myoblasts withdrew from the cell cycle and committed to terminal differentiation, DHFR mRNA levels and DHFR synthesis rates decreased with closely matched kinetics. After 15 to 24 h, committed cells contained 5% the proliferative level of DHFR mRNA (80 molecules per committed cell) and synthesized DHFR protein at 6% the proliferative rate. At no point during the commitment process did the decrease in DHFR synthesis rate exceed the decrease in DHFR message. The decrease in DHFR mRNA levels during commitment was sufficient to account fully for the decrease in rates of DHFR synthesis. Furthermore, DHFR mRNA remained polysomal, and the average number of ribosomes per message remained constant (five to six ribosomes per DHFR mRNA). The constancy of polysome size, along with the uniform rate of DHFR synthesis per message, indicated that DHFR mRNA was efficiently translated in postreplicative cells. The results support a model wherein replication-dependent changes in DHFR synthesis rates are determined exclusively by changes in DHFR mRNA levels.