Electron-positron pair production by linearly polarized photon in the nuclear field

Process of lepton pair production by polarized photon on nuclei can be used to measure the degree of linear polarization of high energy photon. The differential cross section and the analyzing power are calculated with taking into account higher powers of expansion on $Z\alpha$. Pure Coulomb and screened potential are considered.Comment: 12 page

T Cells Bearing a Chimeric Antigen Receptor against Prostate-Specific Membrane Antigen Mediate Vascular Disruption and Result in Tumor Regression.

Aberrant blood vessels enable tumor growth, provide a barrier to immune infiltration, and serve as a source of protumorigenic signals. Targeting tumor blood vessels for destruction, or tumor vascular disruption therapy, can therefore provide significant therapeutic benefit. Here, we describe the ability of chimeric antigen receptor (CAR)-bearing T cells to recognize human prostate-specific membrane antigen (hPSMA) on endothelial targets in vitro as well as in vivo. CAR T cells were generated using the anti-PSMA scFv, J591, and the intracellular signaling domains: CD3ζ, CD28, and/or CD137/4-1BB. We found that all anti-hPSMA CAR T cells recognized and eliminated PSMA(+) endothelial targets in vitro, regardless of the signaling domain. T cells bearing the third-generation anti-hPSMA CAR, P28BBζ, were able to recognize and kill primary human endothelial cells isolated from gynecologic cancers. In addition, the P28BBζ CAR T cells mediated regression of hPSMA-expressing vascular neoplasms in mice. Finally, in murine models of ovarian cancers populated by murine vessels expressing hPSMA, the P28BBζ CAR T cells were able to ablate PSMA(+) vessels, cause secondary depletion of tumor cells, and reduce tumor burden. Taken together, these results provide a strong rationale for the use of CAR T cells as agents of tumor vascular disruption, specifically those targeting PSMA. Cancer Immunol Res; 3(1); 68-84. ©2014 AACR

Champs élastiques et forces configurationnelles dans des tri-cristaux anisotropes: application aux empilements de dislocations aux joints de grains

International audienceProgress in the modeling of the mechanical behavior of metallic polycrystals depends on a better consideration of the interactions between dislocations and crystalline interfaces like grain boundaries. Dislocation pile up mechanisms at grain boundaries are often not well taken into account in crystal plasticity-based micromechanical models due to the discreteness of such mechanisms. The role of crystalline elastic anisotropy on this mechanism is not frequently studied. Here, from the Leknitskii-Eshelby-Stroh (LES) formalism for two-dimensional elastic anisotropy, elastic fields of straight dislocations in bi-materials (bi-crystals) are theoretically calculated using the solution in a homogeneous medium and a "perturbation" for which the solution is derived from the standard analytic continuation method. Besides, in the case of tri-materials (or tri-crystals) where the grain boundary can be considered as an interphase with a certain thickness and stiffness, an alternating technique using the bi-material solution is applied leading to a formal solution in the form of series. The method allows to compute the configurational forces due to the grain boundary on the dislocations ("image forces") as functions of the inter-granular misorientation and the grain boundary elastic stiffness. Furthermore, their effects on discrete dislocation pileup lengths and stress concentrations in the adjacent grain of pileup are discussed.Les progrès dans la modélisation du comportement mécanique des polycristaux métalliques se jouent actuellement par une meilleure prise en compte des interactions entre les dislocations et les interfaces cristallines comme les joints de grains. Les mécanismes d'empilements de dislocations aux joints de grains ne sont pas encore bien pris en compte dans les modèles micromécaniques en plasticité cristalline du fait du caractère discret de ces mécanismes. Le rôle de l'anisotropie élastique cristalline sur ces mécanismes est très peu étudié. Ici, à partir du formalisme de Leknitskii-Eshelby-Stroh (LES) pour l'élasticité anisotrope bi-dimensionnelle, les champs élastiques de dislocations rectilignes dans les bi-matériaux (ou bi-cristaux) sont calculés théoriquement en utilisant la solution du problème homogène et une "perturbation" dont la solution provient d'une méthode standard de continuation analytique. De plus, dans le cas des tri-matériaux (ou matériaux tri-cristallins) où le joint de grains peut être considéré comme une interphase d'une certaine épaisseur et d'une certaine rigidité, une technique appropriée utilisant alternativement la solution du bi-matériau est utilisée conduisant à une solution formelle sous forme de série. La méthode permet en élasticité anisotrope de calculer les forces configurationnelles exercées par le joint de grains sur les dislocations (ou "forces images") en fonction de la désorientation inter-granulaire et de la rigidité du joint de grains. De plus, leurs effets sur les longueurs d'empilements discrets de dislocations et les concentrations de contraintes (cissions résolues) dans le grain adjacent sont discutés

When Online Courses Became the Student Union: Technologies for Peer Interaction and Their Association With Improved Outcomes During COVID-19

While a variety of learning technologies are presently available to facilitate student-to-student peer interactions and collaborative learning online, recent research suggests that students’ opportunities to interact with their peers were significantly reduced following the abrupt transition to remote instruction due to coronavirus disease. This raises concerns because peer interaction is known to be a key ingredient in effective online learning environments, and during remote instruction, the primary connection between a student and their identity as a member of a college community would have been online courses. In this study, we investigate whether and how collaborative technologies supported peer interaction, and students’ learning, during remote instruction. Specifically, we used results from a multicampus survey of students and instructors, as well as data from our online learning management system, to explore the use of collaborative tools at a large scale and their associations with student outcomes. Findings indicate that instructors, as was typical before the pandemic, generally favored individual learning activities over collaborative activities during campus closure. But in those situations where collaborative activities were present during remote instruction, triangulation analyses indicate that their use was related to improved performance as measured by instructors’ survey responses, by students’ performance in their courses, and by an increased sense of belonging among students

Програма, методичні вказівки та контрольні завдання з дисципліни "Сучасні технології вина і коньяку"

Дисципліна "Сучасні технології вина і коньяку" входить до складу рекомендованого переліку навчальних дисциплін нормативної частини освітньо-професійної програми підготовки магістрів спеціальності 181 "Харчові технології", спеціалізації "Технології продуктів бродіння і виноробства". Предметом вивчення навчальної дисципліни "Сучасні технології вина і коньяку" є технологія виноградних та плодово-ягідних вин, коньяків, бренді та інших міцних напоїв, схеми технохімічного і мікробіологічного контролю, методики визначення якісних показників сировини, основних і допоміжних матеріалів, напівпродуктів, готової продукції, вторинних продуктів виноробства й оцінювання їх відповідності вимогам чинної нормативної документації, методики розрахунку продуктів, основних і допоміжних матеріалів, втрат і відходів виробництва. Метою викладання начальної дисципліни "Сучасні технології вина і коньяку" є формування у студентів системи навичок для здійснення ефективної професіональної діяльності на підприємствах виноробної галузі та у наукових закладах в умовах ринкової економіки, технічного переоснащення й удосконалення підприємств, застосування сучасних інноваційних технологій на основі творчого об’єднання і впровадження у виробництво отриманих знань з фундаментальних, загальноінженерних, економічних та спеціальних дисциплін, забезпечення випуску високоякісної продукції з гарантованим ступенем безпеки для людини і навколишнього середовища, оптимальними питомими витратами людської праці, матеріальних та енергетичних ресурсів

Photon emission by an ultra-relativistic particle channeling in a periodically bent crystal

This paper is devoted to a detailed analysis of the new type of the undulator radiation generated by an ultra-relativistic charged particle channeling along a crystal plane, which is periodically bent by a transverse acoustic wave, as well as to the conditions limiting the observation of this phenomenon. This mechanism makes feasible the generation of electromagnetic radiation, both spontaneous and stimulated, emitted in a wide range of the photon energies, from X- up to gamma-rays

White dwarf spins from low mass stellar evolution models

The prediction of the spins of the compact remnants is a fundamental goal of the theory of stellar evolution. Here, we confront the predictions for white dwarf spins from evolutionary models including rotation with observational constraints. We perform stellar evolution calculations for stars in the mass range 1... 3\mso, including the physics of rotation, from the zero age main sequence into the TP-AGB stage. We calculate two sets of model sequences, with and without inclusion of magnetic fields. From the final computed models of each sequence, we deduce the angular momenta and rotational velocities of the emerging white dwarfs. While models including magnetic torques predict white dwarf rotational velocities between 2 and 10 km s$^{-1}$, those from the non-magnetic sequences are found to be one to two orders of magnitude larger, well above empirical upper limits. We find the situation analogous to that in the neutron star progenitor mass range, and conclude that magnetic torques may be required in order to understand the slow rotation of compact stellar remnants in general.Comment: Accepted for A&A Letter