Measuring the metastatic potential of cancer cells

Cancer cells must secrete proteolytic enzymes to invade adjacent tissues and migrate to a new metastatic site. Urokinase (uPA) is a key enzyme related to metastasis in cancers of the lung, colon, gastric, uterine, breast, brain, and malignant melanoma. A NASA technology utilization project has combined fluorescence microscopy, image analysis, and flow cytometry, using fluorescent dyes, and urokinase-specific antibodies to measure uPA and abnormal DNA levels (related to cancer cell proliferation) inside the cancer cells. The project is focused on developing quantitative measurements to determine if a patient's tumor cells are actively metastasizing. If a significant number of tumor cells contain large amounts of uPA (esp. membrane-bound) then the post-surgical chemotherapy or radiotherapy can be targeted for metastatic cells that have already left the primary tumor. These analytical methods have been applied to a retrospective study of biopsy tissues from 150 node negative, stage 1 breast cancer patients. Cytopathology and image analysis has shown that uPA is present in high levels in many breast cancer cells, but not found in normal breast. Significant amounts of uPA also have been measured in glioma cell lines cultured from brain tumors. Commercial applications include new diagnostic tests for metastatic cells, in different cancers, which are being developed with a company that provides a medical testing service using flow cytometry for DNA analysis and hormone receptors on tumor cells from patient biopsies. This research also may provide the basis for developing a new 'magic bullet' treatment against metastasis using chemotherapeutic drugs or radioisotopes attached to urokinase-specific monoclonal antibodies that will only bind to metastatic cells

Analytical study of level crossings in the Stark-Zeeman spectrum of ground state OH

The ground electronic, vibrational and rotational state of the OH molecule is currently of interest as it can be manipulated by electric and magnetic fields for experimental studies in ultracold chemistry and quantum degeneracy. Based on our recent exact solution of the corresponding effective Stark-Zeeman Hamiltonian, we present an analytical study of the crossings and avoided crossings in the spectrum. These features are relevant to non-adiabatic transitions, conical intersections and Berry phases. Specifically, for an avoided crossing employed in the evaporative cooling of OH, we compare our exact results to those derived earlier from perturbation theory.Comment: 5 figures, to be published in Eur. Phys. J.

Faltings heights of abelian varieties with complex multiplication

Let M be the Shimura variety associated with the group of spinor similitudes of a rational quadratic space over of signature (n,2). We prove a conjecture of Bruinier-Kudla-Yang, relating the arithmetic intersection multiplicities of special divisors and big CM points on M to the central derivatives of certain $L$-functions. As an application of this result, we prove an averaged version of Colmez's conjecture on the Faltings heights of CM abelian varieties.Comment: Final version. To appear in Annals of Mat

AN EXPLORATORY STUDY ON CHARACTERS AND RELATIONSHIPS AMONG PARTICIPATION MOTIVATIONS AND RELATED ELEMENTS OF YOUTH BASKETBALL PLAYERS

Problem Statement: Since the Youth Olympic Summer Games became a new global sports event in 2010 and is held every four years, youth athletes’ behaviors and factors that motivated them to continually participate in the sport they choose have become interesting research inquiries: what are the reasons/factors that really motivated them continually engaged in the sports they love? Can these reasons/factors be identified and predicted? Purpose: The purposes of this study were to examine the traits of essential factors that motivated the youth basketball players to participate in their practices and competitions; examine how Gender, Supporting, Goal-setting, Years Playing Basketball related elements impacted their levels of participation-motivations; and the relationships among these psychological needs and motivation factors. Furthermore, the predictors among the psychological needs associated with their essential motivation factors were also explored. Methods: The Adapted Youth Basketball Players' Participation-Motivations Questionnaire was used for data collection; and Self-Determination Theory was used as the theoretical framework; the participants were 253 youth basketball players (Boys = 136, Girls = 117). Data analyses were done by a 2 x 2 x 2 x 2 factorial MANOVA, exploratory factor analysis, and multiple regression analyses. Results: Findings indicate that Supporting and Goal-setting elements had significant effects on the youth basketball players’ participation-motivations, but Gender and Years Play Basketball elements did not. The youth basketball players who were supported by parents possessed higher participant motivations than those supported by their schools. The participants who set their goals for professionals possessed higher participation-motivations than those who set goals for non-professional. Conclusions: In conclusion, through multiple statistics approaches and analyses, the traits and relationships among the youth basketball players’ participation-motivations, and how their motivations associate with the four related elements can be identified and predicted. Article visualizations

Compositional modulation in AlxGa1−xAs epilayers grown by molecular beam epitaxy on the (111) facets of grooves in a nonplanar substrate

We report the first observation of a lateral junction formed in an alloy due to an abrupt transition from segregated to random AlGaAs alloy compositions. Al0.25Ga0.75As epilayers were grown by molecular beam epitaxy on [011-bar] oriented grooves in a nonplanar (100) GaAs substrate. A quasi-periodic modulation of the aluminum concentration occurs spontaneously in material grown on the (111) facets of the groove, with a period of 50–70 Å along the [111] direction. The compositional modulation is associated with a reduction of the band gap by 130 meV, with respect to the random alloy. While segregation of the AlGaAs alloy has been seen previously, this is the first observation of segregation of AlGaAs grown on a (111) surface. The compositional modulation terminates abruptly at the boundaries of the (111) facet, forming abrupt lateral junctions in the AlGaAs layers grown on a groove