cssi/SciSciGPT-SciSciNet huggingface dataset:
Higher order convergence results for the Rayleigh-Ritz method applied to eigenvalue problems: 2. Improved error bounds for eigenfunctions

The application of the Rayleigh-Ritz method for approximating the eigenvalues and eigenfunctions of linear eigenvalue problems in several dimensions is investigated. The object is to improve upon known error estimates for the approximate eigenfunctions. Results for the Galerkin approximation of the eigenfunctions are developed under varying assumptions on the boundary conditions and domain of definition of the eigenvalue problem. These results, coupled with a previous result relating Galerkin and Rayleigh-Ritz approximation of the eigenfunctions, are then used to obtain improved error estimates for the approximate eigenfunctions in theL 2 and uniform norms.
Altruistic and contractual remittances between male and female migrants and households in rural Thailand.

Past research has questioned the extent to which remittances are altruistic behaviors versus payments in a contractual relationship between households and migrants. This article explores altruistic and contractual patterns of remittances using a gendered approach. On the basis of results with various levels of significance in regression models, male and female migrants from Nang Rong, Thailand, behave both altruistically and contractually. However, women and migrants from poorer households behave more altruistically, while men and migrants from richer households behave more contractually. These results point to the need for further research and theory development to explain heterogeneities in migrants’ behavior.
Macroeconomic equilibrium and welfare under simple monetary and switching fiscal policy rules

Abstract Using a standard forward-looking New Keynesian model, this paper investigates rational expectation equilibrium determinacy and macroeconomic performance of simple monetary policy rules under exogenous versus endogenous tax policies when there is tax uncertainty. Under the endogenous tax framework, we found: 1. responding to tax allows monetary policy to have control on the determinacy region, hence higher policy flexibility with respect to the fiscal policy conduct; 2. welfare improvement may come at the expense of cycling. The risk minimizing monetary policy behavior may become problematic since loss function values display huge variations depending on the probabilities given to future tax policy outcomes.
Influence of Distal Resistance and Proximal Vascular Stiffness on Vascular Impedance and Hemodynamics in Pulmonary Hypertension: A Computational Study With Validation Using an Animal Model

Clinically, invasive measurement of pulmonary vascular flow and pressure provides the hemodynamic status of the pulmonary circulation with pulmonary arterial hypertension (PAH). Current diagnostics and therapeutics for PAH revolve around pulmonary vascular resistance (PVR), which is determined by the mean pressure divided by mean flow [1]. Though PVR correlates well with right ventricular (RV) afterload, failure of which is the primary determinant of mortality [2–4], PVR does not provide the complete measure of RV afterload since it neglects dynamic impedance effects [4, 5]. Although we have shown that impedance predicts clinical outcomes better than PVR alone, several key questions remain about the relationship between hemodynamics and impedance changes in pulmonary hypertension.Copyright © 2009 by ASME
Signet-ring cell carcinoma of the colon and rectum: a matched control study.

PURPOSE: There is little information comparing signet-ring cell carcinoma to common non-signet-ring cell colon and rectal cancers. The aim of this study was to better define the clinicopathologic differences between these two distinct entities. METHODS: Using a prospective database of 5,350 surgical patients with rectal cancers operated on at Memorial Sloan-Kettering Cancer Center between 1986 and 1997, 46 patients with signet-ring cell carcinoma were identified. Signet-ring cell carcinoma lesions were those in which signet-ring cells constituted more then 50 percent of the tumor. Six patients who presented with recurrent disease were excluded from the study. Control patients were matched for age, gender, TNM stage, primary site, procedure, and adjuvant therapy. Age, primary site of the tumor, stage at presentation, and survival times of patients with signet-ring cell carcinoma were also compared with 3,371 patients with primary non-signet-ring cell rectal cancers. Survival was calculated using Kaplan-Meier survival estimates. RESULTS: Mean age of the signet-ring cell carcinoma group was 59±12 years and median age was 61 (range, 20–91) years. Male-to-female ratio was 1.1:1. Lymphatic and peritoneal spread was more common among the signet-ring cell carcinoma group. Approximately one-third of signetring cell carcinoma patients presented with metastatic disease. Mean survival time of the signet-ring cell carcinoma group was 45.4 months (95 percent confidence interval, 26.9–63.8) compared with 78.5 months (95 percent confidence interval, 62.0–94.9) for the control patients group;P=0.02 by the log-rank test. The cumulative survival curve of patients with signet-ring cell carcinoma resembles that of patients with poorly differentiated rectal cancers. CONCLUSIONS: Patients with signet-ring cell carcinoma of the colon and rectum have a worse prognosis compared with matched controls with the same stage of disease.
Signal transduction by a protease cascade

The dorsoventral axis of the Drosophila embryo is determined by a spatial cue generated by ovarian somatic cells. This cue is communicated to the embryo through an extracellular serine protease cascade active only on the ventral side of the embryo. Studies of the proteases and somatically expressed proteins involved in this signalling process suggest a working model for how the protease cascade is locally activated hours after the ovarian somatic cells have degenerated.
Predicting interest in and attitudes toward science from personality and need for cognition

Abstract One important task for psychologists of science is to examine the psychological factors (such as personality or cognition) that underlie who becomes interested in science and what kind of attitudes people develop toward science. Those were the primary questions addressed by the present study in a sample of 655 college undergraduates. We predicted that the personality dimensions of openness to experience, conscientiousness, and introversion as well as the cognitive style need for cognition would each predict level of interest in science. Results confirmed these predictions, although the effect sizes tended to be small. Further analyses revealed that need for cognition explained variance in interest in science over and above variance explained by personality.
Agriculture and Nutrition Together Can Meet the Dietary Needs of Kentuckians

Abstract Agriculture and human nutrition are issues with global impacts on economics, environmental stewardship and the healthfulness of individuals. For maximum economic benefits and nutrition, any food resource has to be produced, processed, marketed, and consumed. Traditionally, marketing of a food resource has been the individual farmer selling to wholesale or retail markets with little concern for how the consumer handles and cooks the product. However, in the last few years marketing has evolved to include farmer's markets, roadside markets, commodity groups, and festivals which pair the chef and farmer in restaurant settings, and projects such as the Kentucky Leadership for Agricultural and Environmental Sustainability (KLAES). These activities have built confidence about the future of agriculture. The greatest marketing tool -supporting the health of the individual - has yet to be tapped. By emphasizing safe food handling, cooking techniques, and storage, farmers can increase awareness of their products while providing maximum nutrient value and meal satisfaction. As a result, farmers can increase profits through less waste and increased future purchases. Consumers can eat more healthfully and safely while supporting the state's economy. The Kentucky Cooperative Extension Service in collaboration with state commodity groups developed a 36-page consumer information brochure to educate the consumer both about agriculture products available in our state and how to safely prepare these foods while maximizing nutrient retention. This was first presented during the 1997 Kentucky State Fair's "From Farm to Table - Cooking with Kentucky-Grown Foods" Cooking School. The shared project will continue in local Kentucky communities with similar presentations to consumers and school-age children.
An Efficient Synthesis of Chiral Alcohols via Catalytic Hydrogenation of Esters

A ruthenium complex was found to catalyze the hydrogenation of chiral esters without the loss of their optical purities under mild and neutral conditions. This method can avoid a violent quench step and an extraction step which accompany conventional reduction using metal hydride reagents such as sodium borohydride and lithium aluminum hydride.
Large N gauge theories from orientifolds

We consider four-dimensional N=1 supersymmetric gauge theories obtained via orientifolds of type IIB on Abelian {bold C}{sup 3}/{Gamma} orbifolds. We construct all such theories that have a well-defined world-sheet expansion. The number of such orientifolds is rather limited. We explain this fact in the context of recent developments in four-dimensional type IIB orientifolds. In particular, we elaborate these issues in some examples of theories where a world-sheet description is inadequate due to nonperturbative (from the orientifold viewpoint) states arising from D-branes wrapping (collapsed) two-cycles in the orbifold. We find complete agreement with the corresponding statements recently discussed in the context of type I compactifications on toroidal orbifolds. This provides a nontrivial check for correctness of the corresponding conclusions. We also find nontrivial agreement with various field theory expectations, and point out their origin in string language. The orientifold gauge theories that do possess a well-defined world-sheet description have the property that in the large {ital N} limit computation of any {ital M}-point correlation function in these theories reduces to the corresponding computation in the parent N=4 oriented theory. {copyright} {ital 1998} {ital The American Physical Society}
Glutamine transport by rat basolateral membrane vesicles

Glutamine, a neutral amino acid, is unlike most amino acids, has two amine moieties which underlies its importance as a nitrogen transporter and a carrier of ammonia from the periphery to visceral organs. The gastrointestinal tract utilizes glutamine as a respiratory substrate. The intestinal tract receives glutamine from the luminal side and from the arterial side through the basolateral membranes of the enterocyte. This study characterizes the transport of glutamine by basolateral membrane vesicles of the rat. Basolateral membranes were prepared by a well validated technique of separation on a percoll density gradient. Membrane preparations were enriched with Na+/K+-ATPase and showed no 'overshoot' phenomena with glucose under sodium-gradient conditions. Glutamine uptake represented transport into the intravesicular space as evident by an osmolality study. Glutamine uptake was temperature sensitive and driven by an inwardly directed sodium gradient as evident by transient accumulation of glutamine above the equilibrium values. Kinetics of glutamine uptake under both sodium and potassium gradients at glutamine concentrations between 0.01 and 0.6 mM showed saturable processes with Vmax of 0.39 +/- 0.008 and 0.34 +/- 0.05 nmol/mg protein per 15 s for both sodium-dependent and sodium-independent processes, respectively. Km values were 0.2 +/- 0.01 and 0.55 +/- 0.01 mM, respectively. pH optimum for glutamine uptake was 7.5. Imposition of negative membrane potential by valinomycin and anion substitution studies enhanced the sodium-dependent uptake of glutamine suggesting an electrogenic process, whereas the sodium-independent uptake was not enhanced suggesting an electroneutral process. Other neutral amino acids inhibited the initial uptake of glutamine under both sodium-dependent and sodium-independent conditions. We conclude that glutamine uptake by basolateral membranes occurs by carrier-mediated sodium-dependent and sodium-independent processes. Both processes exhibit saturation kinetics and are inhibited by neutral amino acids. The sodium-dependent pathway is electrogenic whereas the sodium-independent pathway is electroneutral.
Band-Structure Studies on Silicon Using a Metal-Oxide-Semiconductor Junction

Photoemission from solids into a vacuum has hitherto been used in the study of the band structure of solids. Photoemission from one solid into another can also be used to study the band structure. Photoelectric emission from silicon into oxide in a metal-oxide-semiconductor (MOS) geometry is used in this paper for the study of the band structure of silicon. The photoelectric threshold energy is reduced by bias heat treatment of the MOS structure, analogous to the cesiation of the silicon surface, to reduce the work function in vacuum emission studies. In the region below 5.8 eV, we observe four peaks at 3.5, 4.2, 5.0, and 5.7 eV. These results are compared with those observed by Gobeli and Allen in vacuum-emission studies and with the theoretical calculation of Brust. It is concluded that the photoelectric investigation using a MOS geometry is a convenient tool for the study of the band structure of semiconductors.
Thermal fracture of oxidized polydimethylsiloxane during soft lithography of nanopost arrays

During the fabrication of nanopost arrays for measuring cellular forces, we have observed surface cracks in the negative molds used to replicate the arrays from a silicon master. These cracks become more numerous and severe with each replication such that repeated castings lead to arrays with missing or broken posts. This loss in pattern fidelity from the silicon master undermines the spatial resolution of the nanopost arrays in measuring cellular forces. We hypothesized that these cracks are formed because of a mismatch in the coefficient of thermal expansion (CTE) of polydimethylsiloxane (PDMS) and its oxidized surface layer. To study the fracture of PDMS due to thermal effects, we treated circular test samples of PDMS with oxidizing plasma and then heated them to cause surface cracks. These cracks were found to be more abundant at 180 °C than at lower temperatures. Finite element analysis of a bilayer material with a CTE mismatch was used to validate that thermal stresses are sufficient to overcome the fracture toughness of oxidized PDMS. As a consequence, we have ascertained that elevated temperatures are a significant detriment to the reproducibility of nanoscale features in PDMS during replica molding.
Characterization and solid-state transformations of the pseudopolymorphic forms of sodium naproxen

Sodium naproxen is an antiinflammatory nonsteroidal drug used in the treatment of rheumatoid and arthritic diseases. Three pseudopolymorphic forms have been reported in the literature, along with characterizations of anhydrous and dihydrated forms. In the present work, the monohydrated form of sodium naproxen was prepared by dehydration of the dihydrated form and investigated with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and microscopy. Characteristic properties of the monohydrated form were compared to the anhydrous and the dihydrated forms, and the transformation of higher hydrated forms to lower ones was performed in an oven or a desiccator without generating other polymorphic forms. DSC and isothermal TGA experiments determined the structural characteristics and mechanisms by which two types of water were removed from the hydrated species.
Can a two-state MWC allosteric model explain hemoglobin kinetics?

We have analyzed the nanosecond−millisecond kinetics of ligand binding and conformational changes in hemoglobin. The kinetics were determined from measurements of precise time-resolved optical spectra following nanosecond photodissociation of the heme−carbon monoxide complex. To fit the data, it was necessary to extend the two-state allosteric model of Monod, Wyman, and Changeux (MWC) to include geminate ligand rebinding and nonexponential tertiary relaxation within the R quaternary structure. Considerable simplification of the model is obtained by using a linear free energy relation for the rates of quaternary transitions, and by incorporating concepts from recent studies on the physics of geminate rebinding and conformational changes in myoglobin. The model, described by 85 coupled differential equations, quantitatively explains a demanding set of complex kinetic data. Moreover, with the same set of kinetic parameters it simultaneously fits the equilibrium data on ligand binding and the distribution of ...
Antitumor effect of folate-targeted liposomal doxorubicin in KB tumor-bearing mice after intravenous administration.

The effect of folate-targeted liposomal doxorubicin (FTL-Dox) has been well characterized in folate receptor (FR) overexpressing tumors in vitro, particularly in KB human carcinoma cells. However, there are few studies evaluating the in vivo efficacy of FTL-Dox in KB murine xenograft models. In this study, we investigated the antitumor activity of FTL-Dox injected intravenously in mice bearing KB tumors. Folate ligands comprising of folate-polyethyleneglycol-distearoylphosphatidylethanolamine (FA-PEG-DSPE) were synthesized with different MW PEG. To design an optimum FTL-Dox formulation for therapeutic studies, we prepared various FTLs and characterized their in vitro targeting and in vivo tissue biodistribution. Mice were administered a single intravenous injection of free Dox, nontargeted PEGylated liposomal Dox (PL-Dox), or FTL-Dox. FTLs and PLs accumulated similarly in tumor tissue, despite FTLs’ faster clearance from circulation. Mice treated with FTL-Dox 20 mg/kg had a slightly greater tumor growth i...
Cysteine Metabolism in Legionella pneumophila: Characterization of an l-Cystine-Utilizing Mutant

Growth of Legionella pneumophila on buffered charcoal-yeast extract (BCYE) medium is dependent on l-cysteine (but not l-cystine), which is added in excess over what is required for nutrition. We investigated the biochemical and genetic bases for this unusual requirement and determined that much of the l-cysteine in BCYE medium is rapidly oxidized to l-cystine and is unavailable to the bacteria. Analysis of cysteine consumption during bacterial growth indicated that of the 11% consumed, 3.85% (∼0.1 mM) was incorporated into biomass. The activities of two key cysteine biosynthetic enzymes (serine acetyltransferase and cysteine synthase) were not detected in cell extracts of L. pneumophila, and the respective genes were not present in the genome sequences, confirming cysteine auxotrophy. Kinetic studies identified two energy-dependent cysteine transporters, one with high affinity (apparent Km, 3.29 μM) and the other with low affinity (apparent Km, 93 μM), each of which was inhibited by the uncoupling agent carbonyl cyanide m-chlorophenylhydrazone. Cystine was not transported by L. pneumophila; however, a mutant strain capable of growth on l-cystine (CYS1 mutant) transported l-cystine with similar kinetics (Km, 4.4 μM and 90 μM). Based on the bipartite kinetics, requirement for proton motive force, and inhibitor studies, we suggest that a high-affinity periplasmic binding protein and a major facilitator/symporter (low affinity) mediate uptake. The latter most likely is functional at high cysteine concentrations and most likely displays altered substrate specificity in the CYS-1 mutant. Our studies provide biochemical evidence to support a general view that L. pneumophila is restricted to an intracellular lifestyle in natural environments by an inability to utilize cystine, which most likely ensures that the dormant cyst-like transmissible forms do not germinate outside suitable protozoan hosts.
The Present Status of Research on the Zooplankton and Zoobenthos of the Great Lakes

Abstract A brief evaluation of the present status of knowledge concerning the basic ecology of the zooplankton and zoobenthos of the Great Lakes is presented by considering (1) the species of invertebrates that occur in the Great Lakes, (2) how these species are distributed in space and time, and (3) the factors that cause the observed distributions. It is concluded that we are well along at describing what invertebrates occur in the lakes, but there are still major gaps in our knowledge. Regarding distribution, there is now a good data base for describing the distributions of a number of the most important species, but in most cases the results from separate surveys have not been pulled together to develop generalizations with broad application throughout the Great Lakes. Finally, understanding concerning the control of distributions of Great Lakes invertebrates is still at a rudimentary stage, even though such understanding is a basic requirement for evaluating natural and man-induced changes or potential changes in these ecosystems.
Optimal pilot waveform assisted modulation for ultra-wideband communications

Performance of ultra-wideband (UWB) communication systems can be enhanced by collecting multipath diversity gains, once the channels are acquired at the receiver. In this paper, we develop a novel pilot waveform assisted modulation (PWAM) scheme that is tailored for power-limited UWB communications, and can be implemented in analog form. The PWAM parameters are designed to jointly optimize performance and information rate. The resulting transmitter design also minimizes the mean square error (MSE) of channel estimation and thereby achieves the Cramer-Rao lower bound (CRLB).
Elastodynamic boundary element method for piecewise homogeneous media

A general higher-order formulation for the time domain elastodynamic direct boundary element method is presented for computing the transient displacements and stresses in multiply connected two-dimensional solids. The displacement and traction interpolation functions are linear in time and quadratic in space. All integrations are analytical, and are expressed in terms of twelve basic recurring integrals. Causality is ensured by integrating only over the dynamically active parts of each element, and the algorithm presented is time-marching and implicit. The use of analytical integrations allows both unbounded and bounded domain problems to be solved without having to introduce special enclosing elements. All of these improved features allow for a formulation that is very efficient and accurate. The stability and accuracy of the elastodynamic boundary element algorithm is demonstrated by solving several example problems and comparing the results with available analytical and numerical solutions. © 1998 John Wiley & Sons, Ltd.
West Indian Biota in New Caledonia

WHEN visiting New Caledonia last year, my attention was directed to the varied representation of the fauna and flora of the West Indies to be found in the island. New Caledonia is a French colony, and is visited by steamers which go round the world, calling at French ports. There has been commerce by way of the French Antilles, and some of the species accidentally brought from thence have been described as supposedly endemic members of the New Caledonia fauna.
Stable Transfection of Urokinase-Type Plasminogen Activator Antisense Construct Modulates Invasion of Human Glioblastoma Cells

The diffuse and extensive infiltration of malignant gliomas into the surrounding normal brain is believed to rely on modifications of the proteolysis of extracellular matrix components. A key molecule in regulating plasminogen-mediated extracellular proteolysis is the urokinase-type plasminogen activator (uPA). To investigate the role of uPA in the invasive process of brain tumors, we stably transfected a human glioblastoma cell line SNB19 with a vector capable of expressing an antisense transcript complementary to the 1020 bases at the 3' end of the uPA cDNA. Parental, vector-, and antisense construct-stably transfected cell lines were analyzed for uPA mRNA transcript by Northern blot analysis, for uPA enzyme activity by zymography, and for uPA protein levels by Western blotting. The levels of uPA mRNA, protein, and enzyme activities were significantly lower in antisense clones than in parental and vector controls. Radioreceptor binding studies demonstrated that uPA receptor levels remained the same in parental, vector-, and antisense-transfected cells. The antisense-transfected cells showed a markedly lower level of invasion in the Matrigel invasion assays, and their spheroids failed to invade the fetal rat brain aggregates in the coculture system. Green fluorescent protein (GFP) expressing parental and antisense transfectants was generated for detection in mouse brain tissue without any posttreatment. Intracerebral injection of antisense stable transfectants significantly reduced tumor formation compared with that in controls. Our results suggested that down-regulation of uPA expression may be a feasible approach to reducing the malignancy and invasiveness of glial tumors.
A new BIST scheme for 5GHz low noise amplifiers

This paper presents a new low-cost Built-In Self-Test (BIST) circuit for measuring gain, noise figure and input impedance of 5GHz low noise amplifier (LNA). The BIST circuit is designed using 0.18 µm SiGe technology. The test technique utilizes input impedance matching and output transient voltage measurements. The technique is simple and inexpensive.
Implications of the bidders' arrival process on the design of online auctions

We have recently seen a tremendous number of auctions conducted over the Internet. This form of electronic commerce is rapidly growing, and it is projected to account for 30% of all e-commerce by 2002. Using actual bidding transaction data from 324 business-to-consumer online auctions, we analyzed the bidders' arrival process during each auction. We found that most bidders like to sign on early in the auction; typically, 70% of the bidders sign on during the first half. Our statistical analysis reveals that the minimum initial bid is negatively correlated with the number of bidders per auction, while the number of units offered and the length of the auction are positively correlated with the number of bidders. We also present a model for estimating the expected price as a function of the number of bidders, the mean and variance of the private valuation distribution, and the number of units to be sold in the auction. Our analysis shows that increased dispersion in the bidders' values may either increase or decrease the auction price, depending on the bidders' overall arrival process, the length of the auction and the number of units. We calculate the optimal auction length and show that an auction's profit is a unimodal function of its duration and the number of units. This paper also addresses several other economic tradeoffs that are relevant for the optimal design of Internet auctions.
Furrow flexure and ancient heat flux on Ganymede

� 0.5 km, heat fluxes in the range 60–80 mW m � 2 at the time of deformation, and a brittle-ductile transition depth of 2–3 km. The elastic thicknesses are comparable to estimates for grooved terrain on Ganymede, and chaos regions on Europa, and may be characteristic of the point during cooling at which the available stresses can no longer cause significant ice shell deformation. The furrowed dark terrain heat fluxes exceed likely chondritic values, and are plausibly a result of early cooling of Ganymede following accretion. Non-synchronous rotation may have contributed to the 2–3 MPa stresses required to cause the observed deformation. INDEX TERMS: 5418 Planetology: Solid Surface Planets: Heat flow; 5455 Planetology: Solid Surface Planets: Origin and evolution; 5475 Planetology: Solid Surface Planets: Tectonics (8149); 6218 Planetology: Solar System Objects: Jovian satellites; 8149 Tectonophysics: Planetary tectonics (5475). Citation: Nimmo, F., and R. T. Pappalardo (2004), Furrow flexure and ancient heat flux on Ganymede, Geophys. Res. Lett., 31, L19701, doi:10.1029/2004GL020763.
The Uptake and Fate of Radioactive Elements in Trypanosoma Equiperdum

T. equiperdum was supplied by the Walter Reed Army Institute of Research, Division of Veterinary Medicine. The strain was maintained by rat passage every two days. The organisms were separated from infected blood by centrifugation at 2000 r.p.m. for 10 minutes. The trypanosome layer was transferred to a constriction chamber centrifuge tube and again centrifuged for 10 minutes at 2000 r.p.m. The organisms were then transferred to hematocrit tubes
Russian Evacuation Plans—The Fears they Create

Our article in the May-June issue of Foresight** discussed the evacuation plans of the USSR, the importance attributed to them, and the modes of evacuation. As to their effectiveness, we cited our calculations which show that, if the evacuation plans were carried out, the casualties that our missiles could inflict would be well below those suffered by the USSR in the second World War. In fact, even (1) if no Russian first strike which damaged our missile sites were to take place, or if such a strike were completely ineffective, (2) if the Russian missile defense were totally ineffective, and (3) if we were to aim all our missiles at the evacuees — three very unlikely assumptions — the losses caused by our missiles would not exceed 10 million. (The calculations were presented in the July-August 1970 issue of Survive. They have been confirmed since by other sources.) The effectiveness, if any, of our Air Force to cause “destruction ”is much harder to estimate. Its magnitude is highly controversial.
Electromigration lifetime enhancement for lines with multiple branches

With clock or power supply interconnect "trees" there is often a very high current "trunk" feeding current to multiple branches. This work demonstrates and discusses increased "trunk" lifetime with increasing numbers of current branches in a plug-via metal system. The branches act as reservoirs or sources of additional Al and Cu ions, which can re-fill portions of voids and/or slow void growth. It is discussed that any area of metal at a lower current density might be considered a reservoir or source of metal ions for higher current density regions, and can effectively extend the lifetime of the higher current density region. Comparative Black's model parameters are developed and failure analysis is described.
Batrachotoxin: a window on the allosteric nature of the voltage-sensitive sodium channel.

Publisher Summary The voltage-sensitive sodium-channel protein of excitable membranes mediates the fast rising phase of the action potential in a wide variety of tissues. Electrophysiological studies, from the pioneering work of Hodgkin and Huxley onward, have now provided a precise phenomenological description of the sodium channel and the sequence of events occurring at that channel during an action potential. In brief, sodium channels in the resting state of an excitable cell exist in a closed, nonconducting conformation. In response to a local depolarization of the membrane the channel protein undergoes time- and voltage-dependent conformational changes, progressing through apparently multiple nonconducting states before reaching an open, conducting state permitting, selectively, the flow of sodium ions from extracellular to intracellular spaces down an electrochemical gradient. This process is termed “activation.” Thus, binding of batrachotoxin—the prototypical and most potent member of the class—at once affects the voltage-dependent processes of sodium-channel activation and inactivation, changes the selectivity of the channel, and alters the single-channel conductance. This chapter focuses on the body of work that underlies this construct, first from the electrophysiological viewpoint and then from the pharmacological and biochemical approaches. The experiments and the data described here are of necessity selected, rather than all inclusive, with an emphasis placed on batrachotoxin along with veratridine, as these two compounds have been investigated more extensively to date.
Scapulothoracic and scapulohumeral exercises: a narrative review of electromyographic studies.

Abstract Study Design Narrative review. Introduction A well-constructed rehabilitation program of the shoulder complex is critical to stabilizing the scapulothoracic and scapulohumeral joints while encouraging normal scapulohumeral rhythm. Review of the literature demonstrates a variety of scapulothoracic and glenohumeral conditioning exercises. Purpose To assist the occupational and physical therapist in prioritizing exercises for a shoulder conditioning program based on a narrative review of electromyographic (EMG) studies of the shoulder. Methods The authors performed a comprehensive literature search of approximately 250 articles describing shoulder (EMG) testing of the rotator cuff and periscapular musculature. Twenty-two articles were selected based on the author's inclusion criteria. The authors developed a flow sheet outlining each exercise, starting and ending positions, principle muscle(s), and description of exercise. Exercises were assigned to two different muscle groups: rotator cuff or periscapular depending on the principle muscles activated. Results The 22 included articles provided an evidenced-based list of exercises aimed to efficiently and maximally recruit specific rotator cuff and periscapular musculature. Based on these 22 articles, the authors were able to establish a useful series of exercises to promote glenohumeral stability and foster normal scapulohumeral rhythm. Those exercises that elicited the highest maximum voluntary isometric contraction recruitment and were cited to be critical for stability and scapulohumeral rhythm were selected for the exercise flow sheet. Conclusions This review provides a useful evidence-based tool to establish a practical shoulder exercise program. Level of Evidence Level 5.
The crystal structure of chorismate lyase shows a new fold and a tightly retained product

The enzyme chorismate lyase (CL) catalyzes the removal of pyruvate from chorismate to produce 4-hydroxy benzoate (4HB) for the ubiquinone pathway. In Escherichia coli, CL is monomeric, with 164 residues. We have determined the structure of the CL product complex by crystallographic heavy-atom methods and report the structure at 1.4-A resolution for a fully active double Cys-to-Ser mutant and at 2.0-A resolution for the wild-type. The fold involves a 6-stranded antiparallel β-sheet with no spanning helices and novel connectivity. The product is bound internally, adjacent to the sheet, with its polar groups coordinated by two main-chain amides and by the buried side-chains of Arg 76 and Glu 155. The 4HB is completely sequestered from solvent in a largely hydrophobic environment behind two helix–turn–helix loops. The extensive product binding that is observed is consistent with biochemical measurements of slow product release and 10-fold stronger binding of product than substrate. Substrate binding and kinetically rate-limiting product release apparently require the rearrangement of these active-site-covering loops. Implications for the biological function of the high product binding are considered in light of the unique cellular role of 4HB, which is produced by cytoplasmic CL but is used by the membrane-bound enzyme 4HB octaprenyltransferase. Proteins 2001;44:304–311. © 2001 Wiley-Liss, Inc.
Anteroposterior tibiofemoral displacements during isometric extension efforts The roles of external load and knee flexion angle

Rehabilitation of knee extensors is a major consideration in patients with cruciate injuries and repairs. Extension exercises, however, can produce undesirable loads on the injured or replaced anterior cruciate ligament (ACL) resulting in permanent stretch of this restraint. Our study measures the tibiofemoral displacements associated with proximal, middle, and distal locations of the external resisting force and knee flexion angles of 30 degrees, 60 degrees, and 90 degrees. Our results show that tibiofemoral displacements are dependent on both location of the external resisting force and knee flexion angle, with anterior displacements being associated with distal displacement of the resistance pad. The results suggest that patients with ACL injuries or repairs conduct extension exercises with a proximal position of the resistance pad to minimize loads and prevent stretching of this constraint.
Focused, Multiple-Pass Cell for Raman Scattering

A simple optical system is described that makes use of a unique property of ellipsoidal mirrors, viz., light brought to one focus will be reflected alternately through the two foci and collapse to the major axis. This system consists of an on-axis ellipsoidal mirror facing a coaxial flat-spherical mirror assembly that is positioned at the minor axis. Calculations indicate that gains of the order of 500 in the light flux at the point of observation should be attainable with low-eccentricity ellipsoids. Raman-scattered light from atmospheric N2 was obtained with a system employing a 0.2 eccentricity ellipsoid. An experimental gain of 93 was determined by the ratio of the scattering with the system to the scattering obtained with one beam. This result is in good agreement with the theory.
Differential video coding of face and gesture events in presentation videos

Currently, bandwidth limitations pose a major challenge for delivering high-quality multimedia information over the Internet to users. In this research, we aim to provide a better compression of presentation videos (e.g., lectures). The approach is based on the idea that people tend to pay more attention to the face and gesturing hands, and therefore these regions are given more resolution than the remaining image. Our method first detects and tracks the face and hand regions using color-based segmentation and Kalman filtering. Next, different classes of natural hand gesture are recognized from the hand trajectories by identifying gesture holds, position/velocity changes, and repetitive movements. The detected face/ hand regions and gesture events in the video are then encoded at higher resolution than the remaining lower-resolution background. We present results of the tracking and gesture recognition approach, and evaluate and compare videos compressed with the proposed method to uniform compression.
Immunological analysis of a destructive pattern of intraocular tumor resolution.

Spontaneous rejection of syngeneic intraocular P91 mastocytoma occurred by a T cell-dependent immune process that produced extensive, irreparable damage to normal ocular tissues indicative of a delayed-type hypersensitivity (DTH) lesion. We investigated the contribution of other effector modalities in this tumor resolution. Antibody was not responsible for either tumor rejection or phthisis of the tumor-containing eye since passively transferred hyperimmune serum failed to produce either tumor rejection or the characteristic ocular lesions. Moreover, the destructive pattern of tumor rejection occurred in splenectomized hosts which had depressed anti-P91 serum antibody and in a congenic strain (B10-.D2oSn) lacking the C5 complement component. The likelihood that tumor necrosis factor (TNF) was involved in this pathogenesis was also ruled out by the observation that P91 tumor cells were not susceptible to lysis by recombinant TNF. A different pattern of tumor resolution was observed when the opposite eye wa...
Coupled baryon diffusion and nucleosynthesis in the early universe

Abstract Detailed calculations of big-bang nucleosynthesis in baryon-inhomogeneous universes show that Ω b can be considerably larger than its limit from standard big-bang nucleosynthesis. Such results require that late-time hydrodynamic effects deplete overproduction of 7 Li and that the QCD surface tension be near the cube of the QCD coexistence temperature for fluctuations of the correct length scales to arise.
Comparison of Mineral and Fiber Nesting Materials

Abstract Dirty and cracked eggs are problems for all egg producers. Attempts have been made to reduce the incidence of damaged eggs by use of various nesting materials. Hansen et al. (1948) found that excelsior gave consistently good results when compared to straw, wood fiber, wood shavings, rice hulls, almond shells, diatomaceous silica pellets and Douglas fir bark cork pellets. Conclusive results were not obtained due to litter conditions. Siegel and Howes (1959) indicated that nesting materials have little effect upon the percentage of clean, cracked or broken eggs provided the nesting material is maintained properly. Shavings, hay or sugar cane frequently required attention as compared to calcined clay. Dawson and Watts (1952) found that condition of floor litter affected egg cleanliness more than nesting material. Eggs averaged being the cleanest on servall and dirtiest with chopped straw, ground corn cobs and chick bed. Other materials used were shavings, excelsior pads…
Combining rules learnt using genetic algorithms for financial forecasting

Financial markets data present a challenging opportunity for the learning of complex patterns not otherwise discernable, and machine learning techniques like genetic algorithms have been noted to be advantageous in this regard. Independent trials of the genetic algorithm are known to explore different parts of the search space and produce solutions which potentially capture different patterns in the data. Additionally, learning in domains prone to noisy data can generate solutions which obtain performance gains by fitting to what essentially is noise in the data. The article investigates possible strategies for combining the rules obtained from independent GA trials with the objective of noise filtering or enhanced pattern detection for improving the overall learning accuracy.
Turbo King: Framework for Large-Scale Internet Delay Measurements

Distance estimation and topological proximity in the Internet have recently emerged as important problems for many distributed applications [1], [10], [11], [19], [29], [31], [40], [41], [44]. Besides deploying tracers and using virtual coordinates, distance is often estimated using end-to-end methods such as King [13] that rely on the existing DNS infrastructure. However, the question of accuracy in such end-to-end estimation and its ability to produce a large-scale map of Internet delays has never been examined. We undertake this task below and show that King suffers from non-negligible error when DNS zones employ geographically diverse authoritative servers or utilize forwarders, both of which are very common in the existing Internet. We also show that King requires insertion of numerous unwanted DNS records in caches of remote servers (which is called cache pollution) and requires large traffic overhead when deployed in large-scale. To overcome these limitations, we propose a new framework we call Turbo King (T-King) that obtains end-to-end delay samples without bias in the presence of distant authoritative servers and forwarders, while consuming half the bandwidth needed by King and reducing the impact of cache pollution by several orders of magnitude. We finish the paper by evaluating Turbo King in several experiments.
A simple formula of current in dipole antennas

A simple and quantitatively accurate representation of the current distribution in a dipole antenna is derived. Numerical data are given and are found to be in good agreement with the experiment when h \geq O.15\lambda .
Cosmological relic density from minimal supergravity with implications for collider physics.

Working within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking, we evaluate the cosmological relic density from lightest neutralinos produced in the early universe. Our numerical calculation is distinct in that it involves direct evaluation of neutralino annihilation cross sections using helicity amplitude techniques, and thus avoids the usual expansion as a power series in terms of neutralino velocity. Thus, our calculation includes relativistic Boltzmann averaging, neutralino annihilation threshold effects, and proper treatment of integration over Breit-Wigner poles. We map out regions of parameter space that give rise to interesting cosmological dark matter relic densities. We compare these regions with recent calculations of the reach for supersymmetry by CERN LEP 2 and Fermilab Tevatron Main Injector era experiments. The cosmologically favored regions overlap considerably with the regions where large trilepton signals are expected to occur at the Tevatron. The CERN LHC pp collider can make a thorough exploration of the cosmologically favored region via gluino and squark searches. In addition, over most of the favored region, sleptons ought to be light enough to be detectable at both LHC and at \ensuremath{\surd}s =500 GeV ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ collider. \textcopyright{} 1996 The American Physical Society.
RecBench: benchmarks for evaluating performance of recommender system architectures

Traditionally, recommender systems have been "hand-built", implemented as custom applications hard-wired to a particular recommendation task. Recently, the database community has begun exploring alternative DBMS-based recommender system architectures, whereby a database both stores the recommender system data (e.g., ratings data and the derived recommender models) and generates recommendations using SQL queries. In this paper, we present a comprehensive experimental comparison of both architectures. We define a set of benchmark tasks based on the needs of a typical recommender-powered e-commerce site. We then evaluate the performance of the "hand-built" MultiLens recommender application against two DBMS-based implementations: an unmodified DBMS and RecStore, a DBMS modified to improve efficiency in incremental recommender model updates. We employ two non-trivial data sets in our study: the 10 million rating MovieLens data, and the 100 million rating data set used in the Netflix Challenge. This study is the first of its kind, and our findings reveal an interesting trade-off: "hand-built" recommenders exhibit superior performance in model-building and pure recommendation tasks, while DBMS-based recommenders are superior at more complex recommendation tasks such as providing filtered recommendations and blending text-search with recommendation prediction scores.
A new method for mapping fields in coupled cylindrical dielectric resonators

We report a new method to excite and image the fundamental mode in coupled cylindrical dielectric resonators (DRs). A microstrip line resonator was used to excite the fundamental mode in the first DR of the coupled DR chain and a ‘dielectric’ pick-up probe was used to map the electric field patterns. The probe consisted of an open-ended tapered stripline sandwiched between two grounded dielectric slabs. Probe's field was polarized and its output was maximum for parallel fields. The experimental field patterns matched the analytical and simulated field patterns at 7.53 GHz.
Generations, Cohorts, and Social Change

The transformations that occur via a succession of cohorts cannot, for basic demographic reasons, be equated to the product of a procession of “generations.”... this brute fact is a profound key to the understanding of social continuity and social change. Indeed, a characteristically human type of society might well be impossible were the demography of the species structured differently.