9,534 research outputs found
SUSY Contributions to and Top Decay
I report on a systematic analysis of the MSSM parameter space to obtain the
best SUSY solution to the anomaly within the constraint of top quark
decay. Phenomenological implications for top decay and direct stop production
at the Tevatron collider are discussed.Comment: Latex file (3 pages)+ 2 ps files containing figures. Invited talk at
SUSY96, Maryland, May 199
Efficacious Additions to the Standard Model
If split supersymmetry can be advocated as a means to have gauge-coupling
unification as well as dark matter, another plausible scenario is to enlarge
judiciously the particle content of the Standard Model to achieve the same
goals without supersymmetry. A simple efficacious example is presented.Comment: 6 pages, no figure, one reference added, version to appear in PL
Macrophage phenotypic subtypes diametrically regulate epithelial-mesenchymal plasticity in breast cancer cells
Background: Metastatic progression of breast cancer involves phenotypic plasticity of the carcinoma cells moving between epithelial and mesenchymal behaviors. During metastatic seeding and dormancy, even highly aggressive carcinoma cells take on an E-cadherin-positive epithelial phenotype that is absent from the emergent, lethal metastatic outgrowths. These phenotypes are linked to the metastatic microenvironment, though the specific cells and induction signals are still to be deciphered. Recent evidence suggests that macrophages impact tumor progression, and may alter the balance between cancer cell EMT and MErT in the metastatic microenvironment. Methods: Here we explore the role of M1/M2 macrophages in epithelial-mesenchymal plasticity of breast cancer cells by coculturing epithelial and mesenchymal cells lines with macrophages. Results: We found that after polarizing the THP-1 human monocyte cell line, the M1 and M2-types were stable and maintained when co-cultured with breast cancer cells. Surprisingly, M2 macrophages may conferred a growth advantage to the epithelial MCF-7 cells, with these cells being driven to a partial mesenchymal phenotypic as indicated by spindle morphology. Notably, E-cadherin protein expression is significantly decreased in MCF-7 cells co-cultured with M2 macrophages. M0 and M1 macrophages had no effect on the MCF-7 epithelial phenotype. However, the M1 macrophages impacted the highly aggressive mesenchymal-like MDA-MB-231 breast cancer cells to take on a quiescent, epithelial phenotype with re-expression of E-cadherin. The M2 macrophages if anything exacerbated the mesenchymal phenotype of the MDA-MB-231 cells. Conclusion: Our findings demonstrate M2 macrophages might impart outgrowth and M1 macrophages may contribute to dormancy behaviors in metastatic breast cancer cells. Thus EMT and MErT are regulated by selected macrophage phenotype in the liver metastatic microenvironment. These results indicate macrophage could be a potential therapeutic target for limiting death due to malignant metastases in breast cancer
Targeting tumor cell motility as a strategy against invasion and metastasis
Advances in diagnosis and treatment have rendered most solid tumors largely curable if they are diagnosed and treated before dissemination. However, once they spread beyond the initial primary location, these cancers are usually highly morbid, if not fatal. Thus, current efforts focus on both limiting initial dissemination and preventing secondary spread. There are two modes of tumor dissemination â invasion and metastasis â each leading to unique therapeutic challenges and likely to be driven by distinct mechanisms. However, these two forms of dissemination utilize some common strategies to accomplish movement from the primary tumor, establishment in an ectopic site, and survival therein. The adaptive behaviors of motile cancer cells provide an opening for therapeutic approaches if we understand the molecular, cellular, and tissue biology that underlie them. Herein, we review the signaling cascades and organ reactions that lead to dissemination, as these are non-genetic in nature, focusing on cell migration as the key to tumor progression. In this context, the cellular phenotype will also be discussed because the modes of migration are dictated by quantitative and physical aspects of the cell motility machinery.National Institute of General Medical Sciences (U.S.)National Cancer Institute (U.S.
Solutions to the R_b, R_c and alpha_s puzzles by Vector Fermions
We propose two minimal extensions of Standard Model, both of which can easily
accommodate the recent puzzling observations about the excess in , the
deficit in and the discrepancy in the low energy and high energy
determinations of . Each model requires three additional heavy
vectorial fermions in order to resolve the puzzles. The current
phenomenological constraints and the new potential phenomena are also
discussed.Comment: 12 pages, in LaTeX, postscript file also appear
http://www.uic.edu/~keung/pub/rbrc.p
Study of ARPES data and d-wave superconductivity using electronic models in two dimensions
We review the results of an extensive investigation of photoemission spectral
weight using electronic models for the high-Tc superconductors. Here we show
that some recently reported unusual features of the cuprates namely the
presence of (i) flat bands, (ii) small quasiparticle bandwidths, and (iii)
antiferromagnetically induced weight, have all a natural explanation within the
context of holes moving in the presence of robust antiferromagnetic
correlations. Introducing interactions among the hole carriers, a model is
constructed which has superconductivity, an optimal
doping of (caused by the presence of a large density of states at
the top of the valence band), and a critical temperature .Comment: 11 pages Z-compressed postscript, to appear in the Proceedings to the
Stanford Conference on Spectroscopies in Novel superconductor
Mothers' food choices and consumption of ultra-processed foods in the Brazilian Amazon: A grounded theory study
In recent decades, an increase in consumption of ultra-processed foods (UPF), a type of product frequently associated with diet-related obesity, chronic diseases, decrease of eating traditions and loss of culinary diversity, has been observed in middle-income countries. However, there is lack of information on factors related to choosing UPF. In this study, we aimed to understand the factors promoting UPF choices and consumption among mothers living in an urban context in the Brazilian Amazon, and to present a conceptual model grounded on their experiences that illustrates the dynamics between the observed factors. For this qualitative study, we used a constructive grounded theory approach, with a theoretical sampling of 40 women, to choose mothers with high and low consumption of ultra-processed foods. Data production and the first steps of analysis were performed concomitantly, followed by four steps of coding focused on creating conceptual categories and explaining the interactions between them. Our findings highlighted the importance of context in promoting UPF choice and consumption, particularly the âfood environmentâ, physical and virtual, and the âsociocultural environmentâ. These contextual aspects interacted with the two main personal aspects influencing participants' UPF consumption, one concerning practices, âcooking behaviorsâ, and the other concerning preferences, âfood tastesâ. Factors such as economic and time constraints were also important and competed to shape eating practices through interactions with participantsâ health valorization. Findings are discussed in relation to food choice theories, social roles and the food environment. Implications for public health initiatives include the importance of considering environmental changes, sociocultural and economic influences, the reliance on UPF, and the role of women in the home, when promoting healthy diets
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