University of California

About: University of California is a education organization based out in Oakland, California, United States. It is known for research contribution in the topics: Population & Layer (electronics). The organization has 55175 authors who have published 52933 publications receiving 1491169 citations. The organization is also known as: UC & University of California System.

A prospective longitudinal study of chemotherapy-induced cognitive changes in breast cancer patients

Abstract: Evidence for chemotherapy-induced cognitive impairment remains inconclusive. This study was designed to determine the trajectory of cognitive function over time in women with breast cancer, who received doxorubicin and cyclophosphamide (AC) alone or followed by a taxane. Associations between changes in cognitive function and potential covariates including anxiety, depression, fatigue, hemoglobin level, menopausal status, and perception of cognitive function were evaluated. The Repeatable Battery for the Assessment of Neuropsychological Status, Stroop Test, and Grooved Pegboard were used to assess cognitive function in a group of 71 women prior to chemotherapy, a week after completing the last cycle of AC, as well as 1 week and 6 months after the completion of all chemotherapy. Cognitive impairment was found in 23% of women prior to chemotherapy. Hierarchical linear modeling showed significant decreases after receiving chemotherapy followed by improvements 6 months after the completion of chemotherapy in the cognitive domains of visuospatial skill (p < 0.001), attention (p = 0.022), delayed memory (p = 0.006), and motor function (p = 0.043). In contrast, immediate memory, language, and executive function scores did not change over time. These results suggest that having a breast cancer diagnosis may be associated with cognitive impairment. While chemotherapy may have a negative impact on cognitive function, chemotherapy-related impairments appear to be more acute than chronic side effects of therapy. Further studies are needed to provide insight into the clinical significance and potential mechanisms of cancer and treatment-related cognitive impairments.

Remote Sensing of the Distribution and Extent of Wetlands in the Amazon Basin

Abstract: Basin-wide mosaics of synthetic aperture radar (SAR) data, validated with airborne videography, were used to map the extent and distribution of Amazonian wetlands. Cover states consisted of classes determined by vegetation physiognomy (non-vegetated, herbaceous, shrub, woodland, and forest) and by inundation state (flooded or non-flooded). About one-fourth of wetlands are in the Madeira basin. Large wetland features occur in the Maranon (Maranon-Ucayali palm swamps), Negro (Roraima savanna; Negro-Branco interfluvial wetlands), and Madeira (Llanos de Moxos) basins. The mainstem Amazon floodplain, with less than 2% of the total basin area, accounts for about 12% of the basin’s wetlands. Basin-wide, about three-fourths of wetlands are covered by forest, woodland or shrubland. All large watersheds west of the Negro are at least 85% forested. The Madeira basin has the highest percentage of herbaceous wetlands. Numerous remote sensing studies of wetlands using SAR, passive microwave and optical data for selected areas that complement these basin-wide values are summarized.

The Cassini Ion and Neutral Mass Spectrometer (INMS) Investigation

Abstract: The Cassini Ion and Neutral Mass Spectrometer (INMS) investigation will determine the mass composition and number densities of neutral species and low-energy ions in key regions of the Saturn system. The primary focus of the INMS investigation is on the composition and structure of Titan’s upper atmosphere and its interaction with Saturn’s magnetospheric plasma. Of particular interest is the high-altitude region, between 900 and 1000 km, where the methane and nitrogen photochemistry is initiated that leads to the creation of complex hydrocarbons and nitriles that may eventually precipitate onto the moon’s surface to form hydrocarbon—nitrile lakes or oceans. The investigation is also focused on the neutral and plasma environments of Saturn’s ring system and icy moons and on the identification of positive ions and neutral species in Saturn’s inner magnetosphere. Measurement of material sputtered from the satellites and the rings by magnetospheric charged particle and micrometeorite bombardment is expected to provide information about the formation of the giant neutral cloud of water molecules and water products that surrounds Saturn out to a distance of ~12 planetary radii and about the genesis and evolution of the rings.

Best Choices for Regularization Parameters in Learning Theory: On the Bias-Variance Problem

Abstract: whereA is an differential operator and L2 is the Hilbert space of square integrable functions on X with measure ρX on X defined via ρ. This minimization is well-conditioned and solved by straightforward finite dimensional least squares linear algebra to yield fγ,z : X → Y . The problem is posed: How good an approximation is fγ,z to fρ, or measure the error ∫ X(fγ,z − fρ)? and What is the best choice of γ to minimize this error? Our goal in this talk is to give some answers to these questions.

An experimental study of the motion of concentrated suspensions in two-dimensional channel flow. Part 2. Bidisperse systems

Abstract: In this paper we report experimental velocity and concentration profiles for suspensions possessing a bidisperse distribution of particle size undergoing pressure-driven flow through a parallel-wall channel. In addition to the overall concentration distributions determined by implementing the modified laser Doppler velocimetry method described in Part 1 (Lyon & Leal 1998), concentration profiles for the particles of each size were measured by sampling the position of marked tracer particles across 60% of the channel gap. Non-uniform overall particle concentration distributions and blunted velocity profiles were found at bulk particle volume fractions of 0.30 and 0.40, which were equal to the monodisperse data of Part 1, within experimental uncertainty. The large-particle concentration profiles were non-uniform down to a large-particle bulk volume fraction of 0.075, while non-uniform distributions of the small particles were only found when the volume fraction of small particles in the bulk was greater than or equal to 0.20. Experiments in which at least half the suspended particulate volume was occupied by large particles revealed enrichment of the large particles in the centreline region of the channel. This size segregation was found to increase as the total number of suspended particles decreased. Finally, the data from experiments in which a uniform small-particle concentration profile was measured were compared with suspension balance model (McTigue & Jenkins 1992; Nott & Brady 1994) predictions for parameter values that corresponded only to the large particles. While close agreement with the large-particle concentration profiles was found, this comparison also reflected the fact that the small particles bring the suspension viscosity to a regime that is more sensitive to the particle concentration, rather than simply providing an increment in background viscosity to the suspending liquid.