Showing papers by "University of California published in 1993"

Scale and multiple psychologies of space

Abstract: The importance of scale to the psychology of space (perception, thinking, memory, behavior) is discussed. It is maintained that scale has an important influence on how humans treat spatial information and that several qualitatively distinct scale classes of space exist. Past systems of classification are reviewed and some novel terms and distinctions are introduced. Empirical evidence for the need to distinguish between spatial scales is presented. Some implications of these scale distinctions are briefly considered and research needs identified.

Mind, matter, and quantum mechanics

Abstract: The purpose of this work is to resolve together four basic questions concerning the nature of nature. These questions are: (1) How is mind related to matter? (2) How is quantum theory related to reality? (3) How is relativity theory reconciled globally with that which locally we experience directly, namely the coming of reality into being or existence? (4) How is relativity theory reconciled with the apparent demand of Bell’s theorem that what happens in one spacetime region must, in certain situations, depend on decisions made in a spacelike-separated region? These four questions will be discussed in detail later. They are probably the four most fundamental questions in science.

Cardiac imaging and ablation catheter

Abstract: Method and apparatus for ablation of cardiac tissue includes a catheter (2, 60) having an elongated flexible body (6, 64), a tissue characterization assembly including a transducer (34) at the distal end (16) of the body and a tissue ablation assembly having a tissue ablation tip (32) at the distal end of the body. The tissue ablation tip is positioned adjacent the tissue to be ablated using the visualization assembly and then activated.

The importance of modeling interoccasion variability in population pharmacokinetic analyses

Abstract: Individual pharmacokinetic parameters may change randomly between study occasions. Analysis of simulated data with NONMEM shows that ignoring such interoccasion variability (IOV) may result in biased population parameter estimates. Particular parameters affected and the extent to which they are biased depend on study design and the magnitude of IOV and interindividual variability. Neglecting IOV also results in a high incidence of statistically significant spurious period effects. Perhaps most important, ignoring IOV can lead to a falsely optimistic impression of the potential value of therapeutic drug monitoring. A model incorporating IOV was developed and its performance in the presence and absence of IOV was evaluated. The IOV model performs well with respect to both model selection and population parameter estimation in all circumstances studied. Analysis of two real data examples using this model reveals significant IOV in all parameters for both drugs and supports the simulation findings for the case that IOV is ignored: predictable biases occur in parameter estimates and previously nonexistent period effects are found.

Comparative genomic hybridization

Abstract: Disclosed are new methods comprising the use of in situ hybridization to detect abnormal nucleic acid sequence copy numbers in one or more genomes wherein repetitive sequences that bind to multiple loci in a reference chromosome spread are either substantially removed and/or their hybridization signals suppressed. The invention termed Comparative Genomic Hybridization (CGH) provides for methods of determining the relative number of copies of nucleic acid sequences in one or more subject genomes or portions thereof (for example, a tumor cell) as a function of the location of those sequences in a reference genome (for example, a normal human genome). The intensity(ies) of the signals from each labeled subject nucleic acid and/or the differences in the ratios between different signals from the labeled subject nucleic acid sequences are compared to determine the relative copy numbers of the nucleic acid sequences in the one or more subject genomes as a function of position along the reference chromosome spread. Amplifications, duplications and/or deletions in the subject genome(s) can be detected. Also provided is a method of determining the absolute copy numbers of substantially all RNA or DNA sequences in subject cell(s) or cell population(s).

Method for performing a gastric wrap of the esophagus for use in the treatment of esophageal reflux

Abstract: The invention provides a method of fundoplication of the stomach to the esophagus comprising introducing an esophageal manipulator (72) into the stomach lumen (10), maneuvering the manipulator within the lumen so as to create an intussusception (48) of the esophagus (14) into the stomach, introducing a stapler (68) to the lumen of the stomach, and stapling the intussuscepted esophagus to the stomach operation of the stapler is from within the lumen of the stomach. The invention also provides a medical or surgical stapler comprising an elongated body (80) having a passageway (70) which is adapted to receive a medical component such as a forceps (72) or fluid.

The Fisher, Neyman-Pearson Theories of Testing Hypotheses: One Theory or Two?

Abstract: The Fisher and Neyman-Pearson approaches to testing statistical hypotheses are compared with respect to their attitudes to the interpretation of the outcome, to power, to conditioning, and to the use of fixed significance levels. It is argued that despite basic philosophical differences, in their main practical aspects the two theories are complementary rather than contradictory and that a unified approach is possible that combines the best features of both. As applications, the controversies about the Behrens-Fisher problem and the comparison of two binomials (2 × 2 tables) are considered from the present point of view.

Introduction to Information

Abstract: Information is central to all applied studies in economics and other sciences. It has many facets. As empirical data it provides the basis for testing an economic model or theory. It is also intimately connected with decision making under conditions of risk and uncertainty. Hence the choice of optimal policy under an uncertain environment depends on the type of information structures e.g., is it partial or total, incomplete or complete and imprecise or precise?

Methods and compositions for in vivo gene therapy

Abstract: Novel methods and compositions are provided for introducing a gene capable of modulating the genotype and phenotype into two or more tissues following systemic administration. The gene can be introduced into a mammalian host by way of an expression vector either as naked DNA or associated with lipid carriers, particularly cationic lipid carriers. Multiple individual tisssues can be transfected using naked DNA. Using a DNA: lipid carrier complex, multiple tissues and cell types can be transfected. The techniques and compositions find use in the palliation or treatment of any of a variety of genetic-based disorders.

Comparative genomic hybridization (cgh)

Abstract: Disclosed are new methods comprising the use of in situ hybridization to detect abnormal nucleic acid sequence copy numbers in one or more genomes wherein repetitive sequences that bind to multiple loci in a reference chromosome spread are either substantially removed and/or their hybridization signals suppressed. The invention termed Comparative Genomic Hybridization (CGH) provides for methods of determining the relative number of copies of nucleic acid sequences in one or more subject genomes or portions thereof (for example, a tumor cell) as a function of the location of those sequences in a reference genome (for example, a normal human genome). The intensity(ies) of the signals from each labeled subject nucleic acid and/or the differences in the ratios between different signals from the labeled subject nucleic acid sequences are compared to determine the relative copy numbers of the nucleic acid sequences in the one or more subject genomes as a function of position along the reference chromosome spread. Amplifications, duplications and/or deletions in the subject genome(s) can be detected. Also provided is a method of determining the absolute copy numbers of substantially all RNA or DNA sequences in subject cell(s) or cell population(s).

Brain Stimulation in the Study of Neuronal Functions for Conscious Sensory Experiences

Abstract: Some features of cerebral neuronal functions that are uniquely related to generation of conscious sensory responses, have been discovered. Included are two temporal factors: (1) Substantial delays, of up to about 0.5 sec, before achieving cerebral “ neuronal adequacy“ appear to be required for eliciting a sensory experience. This includes the demonstration that a cortical stimulus (C) can retroactively modify a skin (S)-induced sensation even when C stimulus begins up to 500 msec after S stimulus. (2) However, there appears to be a subjective referral of the experience back to the time of the cortical primary evoked response to S; subjectively the skin sensation would thus appear to have no delay. Stimuli that are inadequate for eliciting conscious sensory experience can nevertheless evoke considerable neuronal activity, including that represented in direct cortical responses or in primary (early) components of evoked potentials. Virtually all the qualities of somatic sensation (except pain) can be elicited by stimuli at postcentral gyrus, when intensities of suitable trains of pulses are kept down to liminal levels. Some additional implications, for the manner in which mental and neural events are related, are discussed.

Methods and compositions for targeting specific tissue

Abstract: Methods and compositions for preferentially targeting the delivery of a substance to a sub-population of mammalian cells. The vehicle of the invention includes a targeting moiety capable of associating with or forming an envelope defining a compartment that contains the substance to be delivered to the sub-population of cells. The targeting moiety also contains a domain capable of interacting with a member of a binding pair located on the surface of the sub-population of cells.

Factoring integers with the number field sieve

Abstract: In 1990, the ninth Fermat number was factored into primes by means of a new algorithm, the “number field sieve”, which was proposed by John Pollard. The present paper is devoted to the description and analysis of a more general version of the number field sieve. It should be possible to use this algorithm to factor arbitrary integers into prime factors, not just integers of a special form like the ninth Fermat number. Under reasonable heuristic assumptions, the analysis predicts that the time needed by the general number field sieve to factor n is exp((c+o(1))(logn)1/3(loglogn)2/3) (for n → ∞), where c=(64/9)1/3=1.9223. This is asymptotically faster than all other known factoring algorithms, such as the quadratic sieve and the elliptic curve method.

Global linear stability analysis of weakly non-parallel shear flows

Abstract: The global linear stability of incompressible, two-dimensional shear flows is investigated under the assumptions that far-field pressure feedback between distant points in the flow field is negligible and that the basic flow is only weakly non-parallel, i.e. that its streamwise development is slow on the scale of a typical instability wavelength. This implies the general study of the temporal evolution of global modes, which are time-harmonic solutions of the linear disturbance equations, subject to homogeneous boundary conditions in all space directions. Flow domains of both doubly infinite and semi-infinite streamwise extent are considered and complete solutions are obtained within the framework of asymptotically matched WKBJ approximations. In both cases the global eigenfrequency is given, to leading order in the WKBJ parameter, by the absolute frequency ω0(Xt) at the dominant turning point Xt of the WKBJ approximation, while its quantization is provided by the connection of solutions across Xt. Within the context of the present analysis, global modes can therefore only become time-amplified or self-excited if the basic flow contains a region of absolute instability.

Conjugated polymer - acceptor heterojunctions; diodes, photodiodes, and photovoltaic cells

Abstract: This invention relates generally to the fabrication of heterojunction diodes from semiconducting (conjugated) polymers and acceptors such as, for example, fullerenes, particularly Buckminsterfullerenes, C60, and more particularly to the use of such heterojunction structures as photodiodes and as photovoltaic cells.

Capillary array confocal fluorescence scanner and method

Abstract: A laser-excited capillary array scanner including a plurality of capillaries (21) having a parallel, side-by-side, coplanar relationship and a laser-excited confocal fluorescence detector (18) for detecting fluorescence from a selected interior volumes of each of said capillaries (21) sequentially and repetitively during electrophoresis or other separation method. The invention also relates to a method of analyzing a plurality of capillaries (21), with a single scanner (30), by scanning a plurality of capillary passages in side-by-side relationship, and periodically and repetitively detecting florescence from each capillary passage during electrophoresis or any other separation procedure.

Field effect devices having short period superlattice structures using Si and Ge

Abstract: Carrier mobility in a heterojunction field effect device is increased by reducing or eliminating alloy scattering. The active channel region of the field effect device uses alternating layers of pure silicon and germanium which form a short period superlattice with the thickness of each layer in the superlattice being no greater than the critical thickness for maintaining a strained heterojunction. The gate contact of the field effect device can comprise quantum Si/Ge wires which provide quantum confinement in the growth plane, thereby allowing the field effect device to further improve the mobility by restricting phonon scattering. The structure can be used to improve device speed performance.

Magnetic resonance imaging assisted cryosurgery

Abstract: Methods and apparatus for magnetic resonance imaging (MRI) assisted cryosurgery. Optimal probe placements and cooling parameters are calculated prior to cryosurgery using MRI data. A MRI compatible cryoprobe and a stereotactic probe positioning device are provided. The resolution of MR images is enhanced by mounting a radio frequency MR coil on the intracorporeal end of a cryoprobe. During cryosurgery the temperature distribution in the frozen region is solved by determining the boundary of the frozen region and solving the heat equation for the known boundary conditions. During cryosurgery the temperature distribution in the unfrozen region is determined by T1 measurements. The process of freezing is controlled using information from the solution of the energy equation in the frozen region and temperature measurements in the unfrozen region. After cryosurgery the extent of the tissue damage may be ascertained using phosphorus-31 and/or sodium-23 spectroscopy with a special coil set on the cryosurgical probe.

Recent advances in correlation studies of spatial patterns of genetic variation

Abstract: The spatial distribution of genetic variation has long been recognized as an important feature of population genetics. Our understanding of the basic spatial-temporal dynamics of genetic variation in populations continues to improve through theoretical and experimental studies. Dating back to the original work of Wright (1943) and Malecot (1948), theoretical work has indicated that spatial distributions of genetic variation should often differ strongly from random or uniform distributions. Nonrandomness, or spatial structuring, can strongly influence, and be strongly influenced by, many other important aspects of population genetics, including mating system, individual fitness, inbreeding depression, and the action of various other forms of natural selection, including environmental selection (e.g., Sokal, 1979; Epperson, 1990a). A large body of experimental studies of spatial structure of genetic variation confirms the theoretical predictions. Extensive reviews include those by Endler (1977), Bradshaw (1984), Nagylaki (1986), and Slatkin (1985, 1987).

Transcriptional regulation of vascular endothelial growth factor gene expression in ovarian bovine granulosa cells.

Abstract: The expression of vascular endothelial growth factor (VEGF) in cultured bovine granulosa cells has been studied As shown by northern blot analysis, granulosa cells express the VEGF gene Analysis of the VEGF transcripts by the polymerase chain reaction technique shows that granulosa cells express predominantly the smallest VEGF coding forms (VEGF121, and VEGF164) Since in the promoter region of the VEGF gene there are four potential AP-1 sites and two potential AP-2 sites we have studied if TPA and forskolin could regulate VEGF gene expression TPA induces VEGF transcription in a time- and dose-dependent fashion Maximal VEGF mRNA levels are detected 6 h after TPA treatment Induction apparently requires de novo protein synthesis since it does not occur when translation is inhibited by cycloheximide Forskolin, a naturally occurring diterpene that activates adenylylcyclase, also increases VEGF mRNA content in a time-dependent manner Induction does not require de novo protein synthesis and, in c

Health in Prehistoric Populations of the Santa Barbara Channel Islands

Abstract: Skeletal remains from the Santa Barbara Channel Islands, California were analyzed to evaluate the health consequences of an economic shift from a generalized maritime hunting-and-gathering adaptation to one focused increasingly on fishing. Changes in stature and in the frequency of inflammatory bone lesions suggest that health generally declined during this economic shift. This occurred despite an increase in the protein content of the diet. These data provide a basis for evaluating the significance of protein deficiency as a cause of the deterioration in health seen with the development of intensive agriculture.

Sealed micromachined vacuum and gas filled devices

Abstract: A surface and/or bulk micromachined hermetically sealed cavity containing at least one suspended structure in a low pressure ambient, and the associated fabrication method. The cavity is bounded by a thin-film membrane and a substrate which may have a recess. The method can be used for the production, for example, of thermionic-emission vacuum tubes, gas filled tubes and electromechanical devices. In vacuum tubes the cathode is a suspended refractory filament. Other electrodes may also be suspended. In electromechanical devices the suspended members may be cantilever beams capable of low friction motion.

Multiple sort flow cytometer

Abstract: A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane.

Breeding common bean for improved biological nitrogen fixation

Abstract: Common bean (Phaseolus vulgaris L.), which is an important food crop in the Americas, Africa and Asia, usually is thought to fix only small amounts of atmospheric nitrogen. However, field data indicate considerable genetic variability for total N2 fixation and traits associated with fixation. Studies have shown that selection to increase N2 fixation will be successful if: (1) discriminating traits (selection criteria) are measured precisely, (2) variability in germplasm is heritable, (3) selected parents are also agronomically suitable, (4) units of selection facilitate quantification of selection criteria, and (5) a breeding procedure that allows maximum genetic gain for N2 fixation and recombination with essential agronomic traits is chosen. Breeding lines capable of fixing enough atmospheric N2 to support seed yields of 1000-2000 kg ha-1 have been identified and new cultivars with high N2 fixation potential are being released.

Monitoring uterine contractions by radiotelemetric transmission

Abstract: A uterine monitor is provided for gathering characteristic data such as maternal uterine electromyogram, uterine temperature and intra-uterine pressure so that the onset of parturition or labor may be determined. The uterine monitor comprises a remote sensing unit, the remote sensing unit containing sensors which sense uterine temperature, intra-uterine pressure and uterine electromyogram. A transceiver is housed in the remote sensing unit and outputs the sensed signals to an external antenna. A monitoring station is provided for monitoring the sampled signals. Additionally a medication dispenser is provided which may be actuated by the monitoring station upon the onset of parturition or labor.

Negation and aggregates in recursive rules: the LDL ++ approach

Abstract: The problem of allowing non-monotonic constructs, such as negation and aggregates, in recursive programs represents a difficult challenge faced by current research in deductive databases. In this paper, we present a solution that combines generality with efficiency, as demonstrated by its implementation in the new LDL++ system. A novel and general treatment of set aggregates, allowing for user-defined aggregates, is also presented.

Self-assembling polynucleotide delivery system

Abstract: This invention provides a self-assembling polynucleotide delivery system comprising components aiding in the delivery of the polynucleotide to the desired address which are associated via noncovalent interactions with the polynucleotide. The components of this system include DNA-masking components, cell recognition components, charge-neutralization and membrane-permeabilization components, and subcellular localization components. Specific compounds useful in this system are also provided.

Scanning stylus atomic force microscope with cantilever tracking and optical access

Abstract: A scanned-stylus atomic force microscope (AFM) employing the optical lever technique, and method of operating the same. The AFM of the invention includes a light source and a scanned optical assembly which guides a light beam emitted from the laser source onto a point on said cantilever during scanning thereof. A moving laser beam is thus created which will automatically track the movement of the cantilever during scanning. The invention also allows the laser beam to be used to measure, calibrate or correct the motion of the scanning mechanism, and further allows viewing of the sample and cantilever using an optical microscope.