Добірка наукової літератури з теми "Samaresh Basu"

Botanical samaras spin about their centre of mass and create vertical aerodynamic forces which slow their rate of descent. Descending autorotation of animal wings, however, has never been documented. We report here that isolated wings from Anna's hummingbirds, and also from 10 species of insects, can stably autorotate and achieve descent speeds and aerodynamic performance comparable to those of samaras. A hummingbird wing loaded at its base with the equivalent of 50% of the bird's body mass descended only twice as fast as an unloaded wing, and rotated at frequencies similar to those of the wings in flapping flight. We found that even entire dead insects could stably autorotate depending on their wing postures. Feather removal trials showed no effect on descent velocity when the secondary feathers were removed from hummingbird wings. By contrast, partial removal of wing primaries substantially improved performance, except when only the outer primary was present. A scaling law for the aerodynamic performance of autorotating wings is well supported if the wing aspect ratio and the relative position of the spinning axis from the wing base are included. Autorotation is a useful and practical method that can be used to explore the aerodynamics of wing design.

Increased cultural contacts between representatives of different ethnic groups affect the process of self-identification of their members. Especially it concerns migrant communities. Examination of the problem of ethnicity is especially important due to the fact that the ethnic community exists until there are ethnoconsolidating factors. Within the framework of this research factors of Samaras Azerbaijanis ethnic identity were revealed. Representatives of the Azerbaijani community of Samara base their own identity on differential features. Language is the most important factor of ethnic identity. The Azerbaijani language is the most functional in communication with relatives, friends and acquaintances, in the family. The intensity of intra-ethnic contacts leads to the necessity of language skills and stimulates stable reproduction of the ethnic group. Language skills are transmitted to children from their parents and older relatives. Traditional family structure, traditional food, holidays and mourning days are also factors of ethnic identity of Samaras Azerbaijanis. These components allow Samara Azerbaijanis to realize their national identity and to preserve themselves as a cohesive group. Azerbaijanis of Samara realize the importance of these identity factors whose preservation is one of the main aims of national and cultural associations.

Abstract Background. Keratin 17 (K17) is a negative prognostic and predictive biomarker, overexpressed in the biologically most aggressive forms of pancreatic ductal adenocarcinoma (PDAC). In other anatomic sites and disease processes, K17 expression impacts the inflammatory microenvironment, correlating with changes in the expression of inflammatory cytokines and the infiltration of CD8+ T cells. Thus, we hypothesized that K17 expression also impacts the immune response in PDAC. Methods. We aimed to determine the relationship between intratumoral and peritumoral immune cell infiltrates versus K17 expression in tumor cells, using brightfield multiplexed immunohistochemistry (mIHC) and our suite of deep learning tools to quantitatively evaluate the expression of four biomarkers of T-cells and macrophages. The study included a multi-institutional cohort of 235 PDAC cases from Stony Brook University Hospital (n=54), Thomas Jefferson University (n=67), Cedars Sinai Medical Center (n=7) and Know Your Tumor PanCAN-Perthera (n=107). Peritumoral immune cells were scored in zones defined as stromal tissue within ≤25 µm of the closest tumor cell. Intratumor immune cells were defined as those that physically touched or overlapped with tumor cells. Immune cell counts in peritumoral and intratumoral K17-negatvie areas of the tumor were normalized to immune cell counts in K17-positive areas. Results. The density of CD8+ T cells in K17-negative peritumoral zones was greater than in K17-positive peritumoral zones in 82.6% of PDACs. Similarly, the density of intratumoral CD8+ T cells in K17-negative areas was greater than in K17-positive areas in 93.2% of cases. Less striking inverse correlations for immune cell density relative to K17 expression were found for CD4+ peritumor lymphocytes and both intratumoral and peritumor CD16+ macrophages. By contrast, CD163+ (tumor-promoting) macrophages were more numerous in K17+ peritumoral and intratumoral zones. All differences were statistically significant and independent of tumor grade, stage, histologic subtype, and neoadjuvant treatment history (p< 0.0001). Conclusions. Correlations between K17 and inflammatory cells suggests K17 expression negatively influences the number and infiltration of T-cells and contributes to the marked immunosuppressive effect of PDAC. These findings suggest that the biologic impact of K17 goes beyond its role as a negative prognostic biomarker that impacts tumor growth, metastasis, and chemoresistance, to suppress the immune response to PDAC. Understanding how K17 influences immune cell function may inform future immunotherapeutic opportunities for PDAC treatment. Citation Format: Lyanne Oblein, Sruthi Babu, Mariana Torrente-Goncalves, Lucia Roa, Michael Horowitz, Mahmudul Hasan, Danielle Fassler, Jaymie Oentoro, Emanuel Petricoin, Lynn M. Matrisian, Natalia Marchenko, Edik Blais, Felicia Allard, Ali Alkalin, Wei Jiang, Brent Larson, Andrew Hendifar, Chao Chen, Shahira Abousamra, Dimitris Samaras, Tahsin Kurc, Joel Saltz, Luisa Escobar-Hoyos, Kenneth Shroyer. Keratin 17 excludes CD8-positive T cells and recruits CD163-positive macrophages in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B041.