cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of rate of sampling on the transient behavior of thermogravitational thermal diffusion columns without reservoirs

In experimental investigations of the transient behavior of batch thermogravitational thermal diffusion columns it is expedient to obtain more than one sample from the column during a single run. Such sampling modifies the true batch nature of the column and thereby influences the experimental measurements to some degree. A combined theoretical and experimental investigation was carried out to determine the extent of the influence of sampling rate and thereby provide a means of predetermining a suitable sampling rate. The theoretical analysis was made by approximating the intermittent sampling as a continuous flow through the column. The transport equation of Furry, Jones, and Onsager was applied in the analysis, and an analytical solution was obtained for small separations of equicomposition binary solutions. The series solution is presented in the form of a graph. Experimental data were obtained in two thermogravitational columns with different plate spacings to test the theory. The effect of sampling rate was investigated, and theory and experiments were found to be in good agreement. It is concluded that the theory is entirely adequate to permit the prediction of sampling rates which will yield the maximum number of samples without disturbing the true batch behavior of the column.
Influence of irradiation on resistance to infection.

Infection is a very frequent lethal complication of wholebody x radiation in the LD/sub 50/ to LDi/sub 100/ range of dosage. Normal defenses against infection depend upon several factors, including the polymorphonuclear leucocytes, antibodies, bactericidal power of serum, and the retictiloendothelial system. The effects of x-radiation damage on these mechanisms are discussed. The beneficial effect of spleen homogenates and spleen shielding and previous treatment with endotoxins in radiation induced infections are discussed. Possible reaction mechanisms involved are considered. 57 references. (C.H.)
A two-generation analysis of pollen pool genetic structure in flowering dogwood, Cornus florida (Cornaceae), in the Missouri Ozarks.

Anthropogenic landscape change can disrupt gene flow. As part of the Missouri Ozark Forest Ecosystem Project, this study examined whether silvicultural practices influence pollen-mediated gene movement in the insect-pollinated species, Cornus florida L., by comparing pollen pool structure (Φ s t ) among clear-cutting, selective cutting, and uncut regimes with the expectation that pollen movement should be least in the uncut regime. Using a sample of 1500 seedlings-10 each from 150 seed parents (43 in clear-cut, 74 in selective, and 33 in control sites) from six sites (each ranging from 266 to 527 ha), eight allozyme loci were analyzed with a pollen pool structure approach known as TWOGENER (Smouse et al., 2001; Evolution 55: 260-271). This analysis revealed that pollen pool structure was less in clear-cut (Φ C = 0.090, P < 0.001) than in uncut areas (Φ U = 0.174, P < 0.001), with selective-cut intermediate (Φ S = 0.125, P < 0.001). These estimates translate into more effective pollen donors (N c p ) in clear-cut (N c p = 5.56) and selective-cut (N e p = 4.00) areas than in uncut areas (N e p = 2.87). We demonstrate that Φ C ≤ Φ S ≤ Φ U , with Φ C significantly smaller than Φ U (P < 0.034). The findings imply that, as long as a sufficiently large number of seed parents remain to provide adequate reproduction and to avoid a genetic bottleneck in the effective number of mothers, silvicultural management may not negatively affect the effective number of pollen parents, and hence subsequent genetic diversity in Cornus florida.
Inhibition of α1-adrenergic responsiveness in intact cells by a new, irreversible receptor antagonist

A novel α1-adrenoreceptor antagonist, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-bicyclo [2.2.2] octa-2,5-dienylcarbonyl) piperazine, was synthesized and shown to potently block α1-adrenoreceptor-induced Ca2+ mobilization in intact rat parotid acinar cells. Irreversible inhibition was complete in <5 min. This alkylating prazosin derivative blocked Ca2+ release (IC50 ∼5×10−10M) and [3H]-prazosin membrane binding (IC50 ∼3×10−10M) in a concentration dependent fashion and increased the EC50 of epinephrine for Ca2+ efflux by ∼35 fold. The agent however had no effect on muscarinic receptor-induced Ca2+ mobilization, or β-adrenoreceptor-induced protein secretion, from cells. These findings suggest that this irreversible α1-adrenoreceptor antagonist will be a valuable tool in probing α1-adrenoreceptor function and metabolism in intact cells.
Designing polyethylene terephthalate-based barrier resins

We have studied the efficiencies of commercially available barrier resins used for food packaging and beverage bottle applications and compared them with resins made using copolymer and blending approaches. The effects of various copolymer related parameters that influence oxygen barrier performance and the underlying mechanisms for these effects in PET-based copolymers and blends were investigated. Using these approaches, it is possible to make highly effective PET-based copolymers for gas barrier applications. Blending of PET with phenolic and other organic materials shows equivalent barrier performance in PET copolymers having comonomer levels of <8-mole %. Reduction in oxygen permeation rates results from the reduction or elimination of short range molecular motion of polyethylene terephthalate molecules. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
HOUSEWORK: PRICELESS OR VALUELESS?

Two ways of estimating the value of housework are currently used. One is the opportunity cost approach, which sets the value of work done at home equal to the income the person could earn in the labor market. The other is the market cost approach, which uses the cost of hiring someone to do the housework to determine its value. In this study we use data on earnings of female clerical workers with various patterns of labor force participation to obtain estimates of the opportunity cost of hometime for such women. We find that potential market earnings do not provide an acceptable estimate of the value of housework, and suggest that using the wages of general household workers is a better approach.
NUTRIENT SOLUTION CONCENTRATION AFFECTS GROWTH OF SUBIRRIGATED BEDDING PLANTS

To evaluate the effects of nutrient solution concentration on growth of alyssum [Lobularia maritima (L.) Desv. ‘New Carpet of Snow’], celosia (Celosia argentea L. ‘Gloria Scarlet’), dianthus (Dianthus chinensis L. ‘Telstar Crimson’), gomphrena (Gomphrena globosa L. ‘Gnome White’), stock [Matthiola incana (L.) R. Br ‘Special Mix’], and zinnia (Zinnia elegans Jacq. ‘Dreamland Mix’), we grew plants with five different concentrations of Hoagland nutrient solution [0.125, 0.25, 0.5, 1.0, and 2.0×full strength; electrical conductivity (EC) of 0.4, 0.7, 1.1, 2.0, and 3.7 dS m−1, respectively]. Plant growth of alyssum was maximized when plants were fertilized with 1.0×concentration of Hoagland solution, resulting in a final growing medium EC of 2.1 dS m−1 (as determined by the pour-through method). Maximum shoot dry mass of celosia was obtained when plants were fertilized with 0.5 to 1.0×concentration of Hoagland solution, resulting in a growing medium EC of 1.1–2.5 dS m−1. Growth of dianthus was best with a 1.0×...
Entrainment in compositionally buoyant plumes

Abstract The forms and growth histories of compositionally buoyant plumes were investigated experimentally by emitting a lower-density fluid into a higher-density fluid from a point-source and also by allowing multiple plumes to rise from an interface between layers of fluid with different densities. Of special interest is the observation that some lower density plumes entrain higher density host material as they rise. This process, which occurs even at very low Reynolds numbers, may be analogous to the mixing of geological materials in igneous plumes and salt diapirs. Entrainment of host fluid up through the base of the carapace occurs in plumes that experience simultaneous cap expansion and vertical ascent at a rate that is dependent on the internal vortical velocity. Such plumes have a viscosity contrast between the host and source fluids near unity and a cap/stem diameter ratio of about 2–3. Plumes that entrain host material change shape from spherical to a form with a flat base and bluntly-pointed tip and decelerate due to an increase in effective density relative to the density of the surrounding host material. The ascent of all plumes with a host/source viscosity ratio within the range 0.1–21 and a density contrast of about 1.5 can be modeled as Stokesian provided that entrainment is accounted for by use of an effective density. Effective density is simply the weighted average density of the plume and entrained host material.
Sialyltransferases in rat brain: intracellular localization and some membrane properties.

Abstract— Total rat cerebral homogenate, with nuclei removed, yielded sialyltransferase activity peaks that were distinct from the protein distribution profile in a continuous sucrose density gradient. Marker enzyme studies and electron microscopic examinations on the gradient fractions suggested that most of the sialyltransferase activities were not associated with the synaptosomes. The sialyltransferases appeared to be localized in the smooth microsomal membranes and the Golgi complex derivatives. The sialyltransferase activities were stimulated by non-ionic detergent mixture, Triton CF-54/Tween 80 (2/1, w/w), the effect being much more pronounced with exogenous substrates. The stimulatory effect was dependent on detergent concentration. With 1 mg detergent mixture per mg enzyme protein, the percent increases in enzyme activities with the different substrates were: endogenous glycolipids, 100; endogenous glycoproteins, 50; exogenous GM1a, 700; exogenous DS-fetuin, 230. The action of the nonionic detergents appears to be on a hydrophobic segment of the enzyme molecule, bearing the active site, which is buried in the membrane lipid bilayer. This was substantiated by the partial trypsin resistance of the sialyltransferase activities and the abolition of that resistance when trypsiniza-tion was performed in the presence of nonionic detergents. Furthermore, the sialyltransferase activities were markedly inhibited by organic solvents; and these inhibitory effects were inversely proportional to the solvent dielectric constants.
Green's-function-quantum-defect treatment of impurity photoionization in semiconductors.

An analytic expression is derived for the photoionization cross section of impurity atoms in semiconductors. The use of a quantum-defect wave function for the impurity ground state permits impurity atoms to be conveniently characterized in terms of ground-state energies. The Coulomb Green's-function and time-dependent perturbation theory are used to calculate the wave function of photoexcited electrons or holes from which the photoionization cross section is obtained. The results apply to shallow or deep levels associated with carriers bound to charged impurity centers. Results for photodetachment of carriers bound to neutral impurities are obtained in the limit where the impurity charge goes to zero. Theoretical cross-section maxima are found to be in remarkably good agreement with experimental results, considering that no free parameters or empirical effective field ratios are employed.
Lightweight inference for automation efficiency

Abstract We explore the role of lightweight inference techniques in creating highly automated engineering support environments for the development of computer-based systems. Lightweight inference techniques are scalable methods for automated reasoning. We outline the types of automation that would be enabled by effective lightweight inference capabilities and survey some promising approaches to realizing the needed capabilities.
Slow pulsar scintillation and the spectrum of interstellar electron density fluctuations

Spectre des fluctuations d'intensite en presence d'une forte scintillation produite par des inhomogeneites de densite electronique dans le milieu interstellaire
Interitem encoding and directed search in free recall

The paper proposes a cognitive structure consistent with principles of encoding and a rule for its utilization in verbal recall. The encoding and utilization rules lead to phenomena similar to known serial position effects. A detailed analysis of overt rehearsal data and other experimental results are presented in support of the claim that encoding and search mechanisms characterized by these rules could be important factors in serial position effects of verbal recall. Similar rules might be helpful in dealing with other tasks which seem to mirror the utilization of a cognitive structure.
Theoretical investigation of 19F NMR chemical shielding tensors in fluorobenzenes

We report the theoretical 19F NMR shielding tensor magnitudes and orientations for a series of fluoroaromatic species, together with a comparison with experimental results. We discuss results for Hartree−Fock (HF) and second-order Moeller−Plesset theory (MP2) geometry optimized structures and HF-gauge including atomic orbitals (HF-GIAO), sum over states-density functional theory-independent gauges for localized orbitals (SOS-DFT-IGLO) and MP2-GIAO shielding calculations, for several basis set arrangements. In general, MP2 and DFT methods show few improvements over HF methods, at the expense of time (MP2) and accuracy (MP2 and DFT). Pure density functionals overestimate the tensor breadths (spans), an effect that is only partially offset by use of hybrid exchange correlation functionals. HF-GIAO methods in general give good overall predictions of 19F shielding tensor elements. In the case of potassium tetrafluorophthalate, we also demonstrate that use of the charge field perturbation-IGLO technique provide...
Atonic Pupil after Cataract Surgery

A dilated, atonic pupil is a recognized but unusual complication of cataract surgery. It appears to be a more common occurrence than the paucity of previously published reports would suggest. In this article, seven cases of post-cataract extraction atonic pupil are described. All patients underwent uneventful cataract extraction with posterior chamber intraocular lens (IOL) implantation. In all except one patient, there was a delay from the time of surgery to the development of the atonic pupil. Pharmacologic testing demonstrated that the site of the lesion was the iris sphincter. Possible pathogenic mechanisms are discussed.
Applications of matrix inversion tomosynthesis

The improved image quality and characteristics of new flat- panel x-ray detectors have renewed interest in advanced algorithms such as tomosynthesis. Digital tomosynthesis is a method of acquiring and reconstructing a three-dimensional data set with limited-angle tube movement. Historically, conventional tomosynthesis reconstruction has suffered contamination of the planes of interest by blurred out-of- plane structures. This paper focuses on a Matrix Inversion Tomosynthesis (MITS) algorithm to remove unwanted blur from adjacent planes. The algorithm uses a set of coupled equations to solve for the blurring function in each reconstructed plane. This paper demonstrates the use of the MITS algorithm in three imaging applications: small animal microscopy, chest radiography, and orthopedics. The results of the MITS reconstruction process demonstrate an improved reduction of blur from out-of-plane structures when compared to conventional tomosynthesis. We conclude that the MITS algorithm holds potential in a variety of applications to improve three-dimensional image reconstruction.
Quasi Real-Time Summarization for Consumer Videos

With the widespread availability of video cameras, we are facing an ever-growing enormous collection of unedited and unstructured video data. Due to lack of an automatic way to generate summaries from this large collection of consumer videos, they can be tedious and time consuming to index or search. In this work, we propose online video highlighting, a principled way of generating short video summarizing the most important and interesting contents of an unedited and unstructured video, costly both time-wise and financially for manual processing. Specifically, our method learns a dictionary from given video using group sparse coding, and updates atoms in the dictionary on-the-fly. A summary video is then generated by combining segments that cannot be sparsely reconstructed using the learned dictionary. The online fashion of our proposed method enables it to process arbitrarily long videos and start generating summaries before seeing the end of the video. Moreover, the processing time required by our proposed method is close to the original video length, achieving quasi real-time summarization speed. Theoretical analysis, together with experimental results on more than 12 hours of surveillance and YouTube videos are provided, demonstrating the effectiveness of online video highlighting.
Dynamic buckling of composite cylindrical panels with high-order transverse shears subjected to a transverse concentrated load

Abstract The characteristics of dynamic buckling of a geometrically non-linear cylindrical laminated composite panel subjected to a transverse concentrated step load applied at the center is studied. Attention is focused on the dynamic stability of a finite element discrete structural system. The sufficient condition for dynamic buckling, from the energy transfer consideration, is defined as the smallest load for which an unbounded motion is initiated at one generalized displacement. In other words, the dynamic buckling load associated with that generalized coordinate can be predicted by the intersecting point on the static equilibrium curve and the zero potential energy curve. This dynamic buckling criterion can also be observed by the existence of an inflection point on the generalized displacement response curve. Considering the multi-degree-of-freedom for the entire structure without damping, the dynamic buckling criterion used in a single-degree-of-freedom model gives the lower-bound dynamic buckling estimate, which will be shown in the results of the dynamic buckling analysis for a laminated composite arch. The possibility of parametric resonance due to the transverse concentrated step load on a geometrically non-linear system is discussed. Furthermore, the dynamic effects for different loading rates of the applied concentrated load are examined. Finally, the study of the damping effect, which raises the dynamic buckling load, is included.
Electrical effects of a highly conductive mass inside the thorax

Abstract Model experiments were conducted using an artificial dipole to determine the effect of the volume of a highly conducting mass (such as the heart) inside a finite volume conductor (such as the body) on the dipole moment obtained from integrals of body surface potentials, and on the boundary potential distribution. In one series of experiments, a dog's urinary bladder filled with fluid of conductivity similar to that of the blood, was placed in a tank having the shape of the human thorax and filled with fluid of conductivity similar to that of the tissues. An electric dipole was placed in direct contact with the bladder, and the effect of varying the volume and the position of the bladder on the boundary potential distribution was studied. It was found that the surface potentials depended greatly on the position and the volume of the bladder. In another series of experiments, the effect of the volume of the bladder on the magnitude of the dipole moment was studied. The results showed that the physical presence of the bladder and the volume of the bladder had a definite effect on the magnitude of the resultant dipole moment. Two empirical equations, describing this effect, were derived.
A Consumer's Guide to LOGIST and BILOG:

Since its release in 1976, Wingersky, Barton, and Lord's (1982) LOGIST has been the most widely used computer program for estimating the parameters of the three-parameter logistic item response model. An al ternative program, Mislevy and Bock's (1983) BILOG, has recently become available. This paper compares the approaches taken by the two programs and offers some guidelines for choosing between the two pro grams for particular applications. Index terms: Bayesian estimation, BILOG, IRT estimation procedures, LOGIST, marginal maximum likelihood, maximum like lihood, three-parameter logistic model estimation pro cedures.
Mercuric chloride and p-chloromercuriphenylsulfonate exert a biphasic effect on the binding of the stimulant [3H]methylphenidate to the dopamine transporter.

Mercuric chloride was found to have a biphasic effect on the binding of the radiolabeled stimulant [3H]methylphenidate to membranes from a crude synaptosomal preparation of rat striatal tissue. Binding was enhanced at low concentrations of HgCl2, reaching a maximum of 62% above control values at 2.5 μ HgCl2. It was inhibited in a dose-dependent manner at concentrations greater than 5 μ HgC12, with an IC50 of 7.2 μ. The increase in binding observed at the low concentrations of HgC12 was shown by Scatchard analysis to be due to an increase in the affinity of [3H]methylphenidate for its binding site on the dopamine transporter, while a decrease in both affinity and Bmax accompanied the reduction of [3H]methylphenidate binding observed at the higher concentrations of the inorganic mercury compound. The sodium salt of the organic mercurial p-chloromercuriphenylsulfonic acid also caused an increase in [3H]methylphenidate binding (159% above controls at 2,000 μ), followed by an immediate decrease in binding at higher concentrations of the reagent. Because both of these mercury-containing compounds have a high propensity for interacting with sulfhydryl groups, these data suggest that the cysteine residues in the dopamine transporter molecule may play an important role in the regulation of stimulant binding to the uptake complex. © 1994 Wiley-Liss, Inc.
Terrestrial gastropod succession in a late Holocene stream deposit in South Texas

Abstract Investigation of snail-bearing alluvium from the Smyth Crossing site in Uvalde County, Texas, indicates that the terrestrial gastropod fauna of this area has been stable for at least 3000 yr. However, relative proportions and presence/absence variations indicate changes in the relative occurrence of preferred microhabitats of certain snails. Gastropods from an excavated soil column reveal a succession of gastropod associations in response to succession of the plant community of the site from a riverside gravel bar to an upland savannah/grassland. Human impact on the gastropods is mostly contemporary, with apparent local extirpations of some species having occurred. The recovered paleofaunas provide no evidence for regional climatic change since 3000 yr B.P.
Closing the Gap with Student Affairs Staff: From Margin to Mainstream.

Faculty and student affairs staff members have long assumed separate roles in educating students, yet they complement each other.
Cordell hull and the implementation of the “good neighbor policy”

(1970). Cordell hull and the implementation of the “good neighbor policy”. Western Speech: Vol. 34, No. 4, pp. 288-299.
Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion

Abstract This study investigates the potential release of PO 4 3 - from carbonate aquifers exposed to seawater intrusion. Adsorption and desorption of PO 4 3 - in the presence of deionized water (DIW) and seawater were conducted on a large block of Pleistocene age limestone to simulate the effects of seawater intrusion into a coastal carbonate aquifer at the laboratory scale. The limestone showed strong adsorption of PO 4 3 - in DIW, while adsorption was significantly less in the presence of seawater. Dissolution of CaCO3 was found to prevent PO 4 3 - adsorption at salinities less than 30 psu. Adsorption of PO 4 3 - was limited at higher salinities (30–33 psu), due to competition with HCO 3 - ions for adsorption sites. At a salinity PO 4 3 - absorption occurred as CaCO3 precipitated. Concentrations of PO 4 3 - between 2 and 5 μmol/L were released by desorption when the limestone was exposed to seawater. The results of this study suggest that as seawater intrudes into an originally freshwater coastal aquifer, adsorbed PO 4 3 - may be released into the groundwater. Consequently, adsorbed PO 4 3 - is expected to be released from coastal carbonate aquifers world-wide as sea level continues to rise exposing more of the freshwater aquifer to seawater.
The diary and life of William Byrd II of Virginia, 1674-1744

In the garden at Westover, the tomb of William Byrd II bears an elaborate epitaph that memorializes this Virginia planter as a man possessing "a great elegance of taste and life, the well-bred gentleman and polite companion." The eulogist makes a big point of emphasizing Byrd's formative experiences during his youth in England and gives the distinct impression that early entree into English polite society was the high point of Byrd's life. Fourteen of twenty-four lines are devoted to a resume of Byrd's educational and social successes in England between the years I 674 and i696, from birth to age twenty-two:
The LTi Cell, an Immunologic Chameleon

Lymphoid tissue inducer (LTi) cells are key components of the machinery required for the construction of the lymphoid structures underlying immune responses. In this issue of Immunity, Vonarbourg et. al. (2010) describe how these cells assume several different guises, each associated with different LTi functions.
Estimation of effective parameters for microperforated panel absorbers and applications

Abstract Microperforated panel absorbers are used in many noise control applications as an alternative to fibrous materials. In the past, perforations were circular in shape. However, perforations are now often pressed or cut into the metal. They are non-circular and are irregular shaped and are difficult to model. A nonlinear least squares data-fitting algorithm is utilized to estimate geometric parameters from measured absorption coefficient data. The circular perforation model proposed by Maa is used in the algorithm. The estimated geometric parameters are then used to calculate transfer impedance with good agreement compared to measured data. The procedure is then used to aid in understanding the effect of manufacturing variations, and dust and fluid contamination on the performance of microperforated panel absorbers.
Wage Inequality, Segregation by Skill and the Price of Capital in an Assignment Model

Some pieces of empirical evidence suggest that in the U.S., over the last few decades, (i) wage inequality between-plants has risen much more than wage inequality within-plants and (ii) there has been an increase in the segregation of workers by skill into separate plants. This paper presents a frictionless assignment model in which these two features can be explained simultaneously as the result of the decline in the relative price of capital. Additional implications of the model regarding the skill premium and the dispersion in labor productivity across plants are also consistent with the empirical evidence.
Uncertainty measures for evidential reasoning I: A review☆

Abstract This paper is divided into two parts. Part I discusses limitations of the measures of global uncertainty of Lamata and Moral and total uncertainty of Klir and Ramer. We prove several properties of different nonspecificity measures. The computational complexity of different total uncertainty measures is discussed. The need for a new measure of total uncertainty is established in Part I. In Part II, we propose a set of intuitively desirable axioms for a measure of total uncertainty and then derive an expression for the same. Several theorems are proved about the new measure. The proposed measure is additive, and unlike other measures, has a unique maximum. This new measure reduces to Shannon's probabilistic entropy when the basic probability assignment focuses only on singletons. On the other hand, complete ignorance—basic assignment focusing only on the entire set, as a whole—reduces it to Hartley's measure of information. The computational complexity of the proposed measure is O(N), whereas the previous measures are O(N 2 ).
Reduction of the Three Dimensional Schrodinger Equation for Multilayered Films

In this paper we present a method for reducing the three-dimensional Schr\"odinger equation to study confined metallic states, such as quantum well states, in a multilayer film geometry. While discussing some approximations that are employed when dealing with the three dimensionality of the problem, we derive a one-dimensional equation suitable for studying such states using an envelope function approach. Some applications to the Cu/Co multilayer system with regard to spin tunneling/rotations and angle-resolved photoemission experiments are discussed.
Thrombosis of Aortic St Jude Valve

Abstract Two patients with thrombus due to a St Jude aortic prosthesis are described. Possible etiological factors are discussed.
Group-theoretic algorithms for matrix multiplication

The exponent of matrix multiplication is the smallest real number ω such that for all e>0, O(nω+e) arithmetic operations suffice to multiply two n×n matrices. The standard algorithm for matrix multiplication shows that ω≤3. Strassen's remarkable result [5] shows that ω≤2.81, and a sequence of further works culminating in the work of Coppersmith and Winograd [4] have improved this upper bound to ω≤2.376 (see [1] for a full history). Most researchers believe that in fact ω=2, but there have been no further improvements in the known upper bounds for the past fifteen years.It is known that several central linear algebra problems (for example, computing determinants, solving systems of equations, inverting matrices, computing LUP decompositions) have the same exponent as matrix multiplication, which makes ω a fundamental number for understanding algorithmic linear algebra. In addition, there are non-algebraic algorithms whose complexity is expressed in terms of ω.In this talk I will describe a new "group-theoretic" approach, proposed in [3], to devising algorithms for fast matrix multiplication. The basic idea is to reduce matrix multiplication to group algebra multiplication with respect to a suitable non-abelian group. The group algebra multiplication is performed in the Fourier domain, and then using this scheme recursively yields upper bounds on ω.This general framework produces nontrivial matrix multiplication algorithms if one can construct finite groups with certain properties. In particular, a very natural embedding of matrix multiplication into C[G]-multiplication is possible when group G has three subgroups H1, H2, H3 that satisfy the triple product property. I'll define this property and describe a construction that satisfies the triple product property with parameters that are necessary (but not yet sufficient) to achieve ω=2.In the next part of the talk I'll describe demands on the representation theory of the groups in order for the overall approach to yield non-trivial bounds on ω, namely, that the character degrees must be "small." Constructing families of groups together with subgroups satisfying the triple product property and for which the character degrees are sufficiently small has turned out to be quite challenging.In [2], we succeed in constructing groups meeting both requirements, resulting in non-trivial algorithms for matrix multiplication in this framework. I'll outline the basic construction, together with more sophisticated variants that achieve the bounds ω
SmartSkip: consumer level browsing and skipping of digital video content

In this paper, we describe an interface for browsing and skipping digital video content in a consumer setting; that is, sitting and watching television from a couch using a standard remote control. We compare this interface with two other interfaces that are in common use today and found that subjective satisfaction was statistically better with the new interface. Performance metrics however, like time to task completion and number of clicks were worse.
The effects of St John's wort (Hypericum perforatum) on human cytochrome P450 activity

Background St John's wort(Hypericum perforatum) is a popular over-the-counter dietary supplement and herbal remedy that has been implicated in drug interactions with substrates of several cytochrome P450 (CYP) isozymes. The effect of St John's wort on CYP activity in vivo was examined with a probe drug cocktail. Methods Twelve healthy subjects (5 female, 7 male) completed this 3-period, open-label, fixed schedule study. Tolbutamide (CYP2C9), caffeine (CYP1A2), dextromethorphan (CYP2D6), oral midazolam (intestinal wall and hepatic CYP3A), and intravenous midazolam (hepatic CYP3A) were administered before, with short-term St John's wort dosing (900 mg), and after 2 weeks of intake (300 mg 3 times a day) to determine CYP activities. Results Short-term administration of St John's wort had no effect on CYP activities. Long-term St John's wort administration caused a significant (P 50% decrease in the area under the plasma concentration-time curve (AUC) when midazolam was administered orally, long-term St John's wort administration caused a 20% decrease in AUC when midazolam was given intravenously. There was no change in CYP1A2, CYP2C9, or CYP2D6 activities as a result of St John's wort administration. Conclusion Long-term St John's wort administration resulted in a significant and selective induction of CYP3A activity in the intestinal wall. St John's wort did not alter the CYP2C9, CYP1A2, or CYP2D6 activities. Reduced therapeutic efficacy of drugs metabolized by CYP3A should be anticipated during long-term administration of St John's wort. Clinical Pharmacology & Therapeutics (2001) 70, 317–326; doi: 10.1016/S0009-9236(01)00127-8
Educating Medical Students about Radiologists' Contributions to Patient Care

I nmanyNorth American medical schools, students take no dedicated radiology courses. In some of these, students still receive instruction from radiologists, who serve as guest instructors in courses offered by other disciplines and multidisciplinary courses. In other schools, radiologists play little or no role in required coursework, and whatever instruction in radiology students receive is provided by physicians in other fields. As a result, many students have little opportunity to learn what radiologists do and, in particular, to gain an understanding of the many ways radiologists contribute to patient care. This is a problem for radiology, the students, and the patients for whom they will care. In thinking about what radiologists contribute to patient care, it is important to distinguish between two fundamentally different categories of contribution: inputs and outputs. The facts that there are more than 30,000 practicing US radiologists and that the average US radiologist performs and interprets more than 15,000 exams per year represent inputs. They tell us that health professionals rely to a great extent on radiology in the care of their patients, but they do not tell us what sort of impact radiologists are actually having on the care of those patients. What really matters most is not the resources being put into radiology but the outputs of radiology in improving care. The most readily apparent contribution radiologists make to the care of patients is found in the area of diagnosis. In many cases, health professionals refer patients for imaging exams with particular diagnostic hypotheses in mind, such as ‘‘right upper quadrant pain—assess for gallstones’’ or ‘‘thunderclap headache—rule out subarachnoid hemorrhage.’’ Under these circumstances, one of the radiologist’s principal missions is to confirm or disconfirm the hypothesis, by determining whether there is evidence of gallstones or subarachnoid hemorrhage. In many cases, such as suspected fracture, the images are completely diagnostic.
Free-exciton diffusion and decay in zero-stress Ge

We report the first direct measurement of the free-exciton (FE) diffusivity D/sub x/ in germanium. The evolution in time of spatial profiles of FE luminescence were measured. From these FE density profiles we determined the diffusivity D/sub x/(4.2 K)approx. =300 cm/sup 2/ s/sup -1/ which is limited by phonon scattering, and the surface recombination velocity Sapprox. =3000 cmX sup -1: , and an FE lifetime tau/sub x/approx. =27 ..mu..s for dislocation free Ge and tau/sub x/approx. =12 ..mu..s for dislocated Ge with surface recombination effects on these tau/sub x/ excluded. Evidence is presented which suggests that the FE recombination velocity S at a crystal surface is not sensitive to the detailed character of that surface. It is concluded that previous measurements could have been dramatically affected by the surface recombination of FE, especially those measurements made on crystals whose dimensions are on the order of the FE diffusion length. An FE-phonon scattering time tau/sub p/(4.2 K)approx. =2 x 10/sup -10/ s is deduced from the measured diffusion constant.
g-factor measurement of the 133 keV level in 131Cs

Abstract The g factor of the 133 keV level in 131Cs has been measured by the differential angular correlation method with an external magnetic field. The result obtained is g = +0.99±0.06.
Gene expression in peripheral arterial chemoreceptors.

The peripheral arterial chemoreceptors of the carotid body participate in the ventilatory responses to hypoxia and hypercapnia, the arousal responses to asphyxial apnea, and the acclimatization to high altitude. In response to an excitatory stimuli, glomus cells in the carotid body depolarize, their intracellular calcium levels rise, and neurotransmitters are released from them. Neurotransmitters then bind to autoreceptors on glomus cells and postsynaptic receptors on chemoafferents of the carotid sinus nerve. Binding to inhibitory or excitatory receptors on chemoafferents control the electrical activity of the carotid sinus nerve, which provides the input to respiratory-related brainstem nuclei. We and others have used gene expression in the carotid body as a tool to determine what neurotransmitters mediate the response of peripheral arterial chemoreceptors to excitatory stimuli, specifically hypoxia. Data from physiological studies support the involvement of numerous putative neurotransmitters in hypoxic chemosensitivity. This article reviews how in situ hybridization histochemistry and other cellular localization techniques confirm, refute, or expand what is known about the role of dopamine, norepinephrine, substance P, acetylcholine, adenosine, and ATP in chemotransmission. In spite of some species differences, review of the available data support that 1). dopamine and norepinephrine are synthesized and released from glomus cells in all species and play an inhibitory role in hypoxic chemosensitivity; 2). substance P and acetylcholine are not synthesized in glomus cells of most species but may be made and released from nerve fibers innervating the carotid body in essentially all species; 3). adenosine and ATP are ubiquitous molecules that most likely play an excitatory role in hypoxic chemosensitivity.
Depression and health-related quality of life in chronic obstructive pulmonary disease.

Abstract Background Prior research on the risk of depression in chronic obstructive pulmonary disease (COPD) has yielded conflicting results. Furthermore, we have an incomplete understanding of how much depression versus respiratory factors contributes to poor health-related quality of life. Methods Among 1202 adults with COPD and 302 demographically matched referents without COPD, depressive symptoms were assessed using the 15-item Geriatric Depression Score. We measured COPD severity using a multifaceted approach, including spirometry, dyspnea, and exercise capacity. We used the Airway Questionnaire 20 and the Physical Component Summary Score to assess respiratory-specific and overall physical quality of life, respectively. Results In multivariate analysis adjusting for potential confounders including sociodemographics and all examined comorbidities, COPD subjects were at higher risk for depressive symptoms (Geriatric Depression Score ≥6) than referents (odds ratio [OR] 3.6; 95% confidence interval [CI], 2.1-6.1; P P P P Conclusions Patients with COPD are at significantly higher risk of having depressive symptoms than referents. Such symptoms are strongly associated with worse respiratory-specific and overall physical health-related quality of life, even after taking COPD severity into account.
The signed-graphic representations of wheels and whirls

We characterize all of the ways to represent the wheel matroids and whirl matroids using frame matroids of signed graphs. The characterization of wheels is in terms of topological duality in the projective plane and the characterization of whirls is in terms of topological duality in the annulus.
Family Patterns of Gender Role Attitudes

Study goals were to identify family patterns of gender role attitudes, to examine the conditions under which these patterns emerged, and to assess the implications of gender attitude patterns for family conflict. Participants were mothers, fathers, and first- and second-born adolescents from 358 White, working and middle-class US families. Results of cluster analysis revealed three gender role attitude patterns: egalitarian parents and children, traditional parents and children, and a divergent pattern, with parents more traditional and children more egalitarian. Mixed-model ANOVAs indicated that these family patterns were related to socioeconomic status, parents’ time spent in gendered household tasks and with children, and the gender constellation of the sibling dyad. The traditional family group reported the most family conflict.
The Dual-Mode Theory of affective responses to exercise in metatheoretical context: II. Bodiless heads, ethereal cognitive schemata, and other improbable dualistic creatures, exercising

According to the Dual-Mode Theory, affective responses to exercise are influenced by the continuous interplay of cortically mediated cognitive processes (e.g., self-efficacy, self-presentational concerns, goals, attributions) and ascending interoceptive cues (e.g., ventilation, acidosis, core temperature). The relative importance of these two factors is hypothesized to shift systematically as a function of exercise intensity, with cognitive factors being the dominant determinants at intensities proximal to the lactate or ventilatory thresholds and interoceptive factors gaining salience at intensities that preclude the maintenance of a physiological steady state. The present review retraces the antecedents of the dual-mode notion in psychological theory. Emphasis is placed on variants of dualistic thought that focus on the ‘mind’ (cognition) as the chief determinant of affect and specifically on the theories of Schachter and Singer, Lazarus, Bandura, Neisser, and Leventhal and Everhart. The applications of...
High-level problems in teaching undergraduate programming languages

This paper discusses several problems in teaching programming languages. A language tends to indoctrinate its users and desensitize us to its problems and limitations. In addition, many language issues don't arise until programs reach a certain scale, which can be difficult to do in a one-semester course. No solution is proposed; instead the focus is to better understand the difficulty of designing an effective curriculum. One way to cut through the accidental combination of surface features in programming languages is to focus on semantics and programs themselves as object of study.
Electron doubly differential cross section for 0.5-MeV H - -He detachment collisions

A comprehensive theoretical treatment is presented for the electron detachment cross section, differential in both electron momentum and direction, for collisions of 0.5-MeV ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ projectiles on He targets. Our calculation, which assumes that the residual H atom is left in the 1s state, employs the usual first Born approximation as well as the closure approximation (in order to sum over all He target final states). Electron correlations within the ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ system are treated in detail within the framework of the adiabatic hyperspherical coordinate approximation. In particular, for the first time for this collision process, angular correlations are included. The s, p, and d partial-wave components of the detached electron hyperspherical coordinate wave function are also included. The helium target is described by the atomic form factor and the incoherent scattering function tabulated by Hubbell et al. as well as by an average He excitation energy, I${\ifmmode\bar\else\textasciimacron\fi{}}_{\mathrm{He}}$. The prescription of Lee and Chen for I${\ifmmode\bar\else\textasciimacron\fi{}}_{\mathrm{He}}$, which for small scattering angles gives the value 35 eV is found to result in the best agreement of our calculated doubly differential cross sections with experiment, both in shape and in predicted peak energies. The unique feature of the experimental doubly differential detachment cross section of Menendez and Duncan, that for electron-scattering angles less than 4\ifmmode^\circ\else\textdegree\fi{} there is a double peak, is reproduced in our calculations. However, the predicted higher-energy peak is smaller in magnitude and higher in energy than that observed experimentally. This difference is attributed to the influence of excited H-atom states, which are measured in the experiments. Fictitious calculations are carried out for the doubly differential cross sections in which the s-wave electron phase shift is fixed at zero radians instead of its true monotonically decreasing value with increasing electron energy from the value \ensuremath{\pi} at threshold. These fictitious calculations demonstrate the disappearance of the double-peak structure of the cross section and confirm the origin of the double peak in the s- and p-wave interference and in the initial \ensuremath{\pi} phase shift of the s partial wave. Though our single differential cross sections differ quantitatively from previous calculations of Maleki and Macek, the approximate factor of 2 discrepancy between the theoretical predictions and the absolute experimental measurements remains unexplained.
Electrohydrodynamic atomization: a versatile process for preparing materials for biomedical applications

Electrohydrodynamic atomization phenomena have increasingly attracted the attention of researchers who are interested in building micro- or nanometer architectures, such as fibers and encapsulated particles with a controllable microstructure. There are two main electrohydrodynamic atomization techniques: electrospraying and electrospinning. These techniques are unique processes in that they produce fibers and particles with dimensions that range from micrometers to nanometers depending on the processing parameters. This paper presents the principles, processes and potential biomedical applications for electrospraying and electrospinning of biomaterials. Both of these techniques offer great research opportunities. Emphasis will focus on the effects of processing parameters of electrohydrodynamic atomization on morphologies and microstructure of the final products. In addition, some potential applications are proposed based on the remarkable characteristics of the biomaterials generated using electrosprayin...