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Molecular motor proteins fulfill the critical function of transporting organelles and other building blocks along the biopolymer network of the cell's cytoskeleton, but crowding effects are believed to crucially affect this motor-driven transport due to motor interactions. Physical transport models, like the paradigmatic, totally asymmetric simple exclusion process (TASEP), have been used to predict these crowding effects based on simple exclusion interactions, but verifying them in experiments remains challenging. Here, we introduce a correlation imaging technique to precisely measure the motor density, velocity, and run length along filaments under crowding conditions, enabling us to elucidate the physical nature of crowding and test TASEP model predictions. Using the kinesin motor proteins kinesin-1 and OSM-3, we identify crowding effects in qualitative agreement with TASEP predictions, and we achieve excellent quantitative agreement by extending the model with motor-specific interaction ranges and crowding-dependent detachment probabilities. These results confirm the applicability of basic nonequilibrium models to the intracellular transport and highlight motor-specific strategies to deal with crowding.

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IntroductionOral cancer accounts for approximately 2.1% of all cancers worldwide. In India, oral squamous cell carcinoma (OSCC) is the most common cancer with half a million new cases diagnosed every year. More than 50% of patients eventually develop local recurrence or metastasis usually within the first 2-years following completion of treatment. It is beneficial to analyze the prognostic significance of Cyclin D1, p53 and EGFR which are critical mediators in the pathogenesis of OSCC. The objective of this study was to assess the association of expression of these markers with recurrence and pattern of recurrence in OSCC patients undergoing chemoradiation.Materials and MethodsA Total 290 OSCC cases of locally advanced stage (III, IV) oral cancer with World Health Organization (W.H.O.) performance status of grade 0/1 in the year 2009–2012 were enrolled in the study. Treatment response was assessed according to W.H.O. criteria. Cyclin D1, EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei.ResultsDuring the 2-years follow up, 56 (19.3%) patients recurred, out of which, 47 (83.9%) were locoregional and 9 (16.1%) distant sites. On correlating, χ2 test showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of marker expressions (Cyclin D1, EGFR and p53) with recurrence. The strong positive expressions of all three markers showed significant association with early time of recurrence. The multivariate logistic regression analysis showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of recurrence with primary site, differentiation, Cyclin D1 and p53 expressions indicating these as an independent predictors of recurrence in OSCC. The Cyclin D1, EGFR and p53 expressions also showed significant (P < 0.001) poor survivals (OS, DFS and RFS) in patients with positive/strong positive expressions than negative expression suggesting their prognosis in OSCC.ConclusionOur results signifies that tumors over expressing Cyclin D1, EGFR and p53 are resistant to chemoradiation and are associated with increased risk of locoregional recurrence and metastasis in OSCC patients undergoing chemoradiation.

Parthenium hysterophorus L. (Asteraceae) is a serious weed of pastures, wasteland and agricultural fields in world. Various problems are posed by the weed to human health, agriculture, live stock production and biodiversity. It is used as folk remedy against various afflictions. The review discusses several prominent biological utilities of P. hysterophorus as it contains several important chemical constituents mainly histamine, saponin, glucosides and triterpene (sesquiterpene) and can be of use for the purpose of biocontrol of various pathogens , for its medicinal utility and even for the purpose of food .