Here, in our approximation of polaron theory, we examine the importance of introducing theT product, which turn out to be a very convenient theoretical approach for the calculation of thermodynamical averages.We focus attention on the investigation of the so-called linear polaron Hamiltonian and present in detail the calculation of the correlation function, spectral function, and Green function for such a linear system.It is shown that the linear polaron Hamiltonian provides an exactly solvable model of our system, and the result obtained (...) with this approach holds true for an arbitrary coupling constant which describes the strength of interaction between the electron and the lattice vibrations. Then, with the help of a variational technique, we show the possibility of reducing the real polaron Hamiltonian to a socalled trial or approximate linear model Hamiltonian.We also consider the exact calculation of free energy with a special technique that reduces calculations with the help of the T product, which, in our opinion, works much better and is easier than other analogous considerations, for example, the path-integral or Feynman-integral method.(1,2)Here we furthermore recall our own work,(4) where it was shown that the results of Refs. 7 and 8 concerning the impedance calculation in the polaron model may be obtained directly without the use of the path-integral method.The study of the polaron system's thermodynamics is carried out by us in the framework of the functional method. A calculation of the free energy and the momentum distribution function is proposed.Note also that the polaron systems with strong coupling(9) proved to be useful in different quantum field models in connection with the construction of dynamical models of composite particles. A rigorous solution of the special strong-coupling polaron problem, describing the interaction of a nonrelativistic particle with a quantum field, was given by Bogolubov.(3) The works of Tavkhelidze, Fedyanin, Khrustalev, and others(10–13) are dedicated to the further development and generalization of the Bogolubov method.Notice, too, that the electron-photon interaction effects play an important part in many problems of modern solid state theory (see, e.g., Refs. 7 and 14–19).The present paper summarizes a set of lectures delivered as a special course in the physics department of Moscow State University. (shrink)

We discuss the main ideas that lie at the foundations of the approximating Hamiltonian method (AHM) in statistical mechanics. The principal constraints for model Hamiltonians to be investigated by AHM are considered along with the main results obtainable by this method. We show how it is possible to enlarge the class of model Hamiltonians solvable by AHM with the help of an example of the BCS-type model.

The Lagrangian and Hamiltonian properties of classical electrodynamics models and their associated Dirac quantizations are studied. Using the vacuum field theory approach developed in (Prykarpatsky et al. Theor. Math. Phys. 160(2): 1079–1095, 2009 and The field structure of a vacuum, Maxwell equations and relativity theory aspects. Preprint ICTP) consistent canonical Hamiltonian reformulations of some alternative classical electrodynamics models are devised, and these formulations include the Lorentz condition in a natural way. The Dirac quantization procedure corresponding to the Hamiltonian formulations is (...) developed. The crucial importance of the rest reference systems, with respect to which the dynamics of charged point particles is framed, is explained and emphasized. A concise expression for the Lorentz force is derived by suitably taking into account the duality of electromagnetic field and charged particle interactions. Finally, a physical explanation of the vacuum field medium and its relativistic properties fitting the mathematical framework developed is formulated and discussed. (shrink)

Fichte’s The Way towards the Blessed Life is a genuinely mystical work that contains several themes characteristic of mystical writing: the opposition of a non-spatio-temporal, non-manifold being to the world as it appears; the ineffability of the Divine; the centrality of union with God and of detachment; and the individual as a conduit for Divine life and love. It must, however, be granted that Fichte conjoins his affirmations of union with denials that the ontological identity of human beings and God (...) is a matter of experience. This is nevertheless an insufficient reason for denying that Fichte’s text is correctly characterized as mystical, for experience of God’s presence is a more adequate criterion of the mystical than the experience of ontological identity or even of union with God, and the experiences that The Way towards the Blessed Life does acknowledge are properly interpreted in terms of Divine presence. (shrink)

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into (...) two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop. (shrink)

This paper offers a contribution to debates around integrative aspects of systems biology and engages with issues related to the circumstances under which physicists look at biological problems. We use oral history as one of the methodological tools to gather the empirical material, conducting interviews with physicists working in systems biology. The interviews were conducted at several institutions in Brazil, Germany, Israel and the U.S. Biological research has been increasingly dependent on computational methods, high-throughput technologies, and multidisciplinary skills. Quantitative scientists (...) are joining biological departments and collaborations between physicists and biologists are particularly vigorous. This state of affairs raises a number of questions, such as: What are the circumstances under which physicists approach biological problems in systems biology? What kind of interdisciplinary challenges must be tackled? The paper suggests that, concerning physicists’ move to work on biological systems, there are common reasons to move, the transition must be understood in terms of degrees, physicists have a rationale for simplifying systems, and distinct conceptions of model and modeling strategies are recurrent. We identified problems regarding linguistic clarity and integration of epistemological aims. We conclude that cultural unconformities within the systems biology community have important consequences to the flow of scientific knowledge. (shrink)

This paper offers a contribution to debates around integrative aspects of systems biology and engages with issues related to the circumstances under which physicists look at biological problems. We use oral history as one of the methodological tools to gather the empirical material, conducting interviews with physicists working in systems biology. The interviews were conducted at several institutions in Brazil, Germany, Israel and the U.S. Biological research has been increasingly dependent on computational methods, high-throughput technologies, and multidisciplinary skills. Quantitative scientists (...) are joining biological departments and collaborations between physicists and biologists are particularly vigorous. This state of affairs raises a number of questions, such as: What are the circumstances under which physicists approach biological problems in systems biology? What kind of interdisciplinary challenges must be tackled? The paper suggests that, concerning physicists’ move to work on biological systems, there are common reasons to move, the transition must be understood in terms of degrees, physicists have a rationale for simplifying systems, and distinct conceptions of model and modeling strategies are recurrent. We identified problems regarding linguistic clarity and integration of epistemological aims. We conclude that cultural unconformities within the systems biology community have important consequences to the flow of scientific knowledge. (shrink)

This paper offers a contribution to debates around integrative aspects of systems biology and engages with issues related to the circumstances under which physicists look at biological problems. We use oral history as one of the methodological tools to gather the empirical material, conducting interviews with physicists working in systems biology. The interviews were conducted at several institutions in Brazil, Germany, Israel and the U.S. Biological research has been increasingly dependent on computational methods, high-throughput technologies, and multidisciplinary skills. Quantitative scientists (...) are joining biological departments and collaborations between physicists and biologists are particularly vigorous. This state of affairs raises a number of questions, such as: What are the circumstances under which physicists approach biological problems in systems biology? What kind of interdisciplinary challenges must be tackled? The paper suggests that, concerning physicists’ move to work on biological systems, there are common reasons to move, the transition must be understood in terms of degrees, physicists have a rationale for simplifying systems, and distinct conceptions of model and modeling strategies are recurrent. We identified problems regarding linguistic clarity and integration of epistemological aims. We conclude that cultural unconformities within the systems biology community have important consequences to the flow of scientific knowledge. (shrink)

© 2015 Elsevier Inc.Postnatal organogenesis occurs in an immune competent environment and is tightly controlled by interplay between positive and negative regulators. Innate immune cells have beneficial roles in postnatal tissue remodeling, but roles for the adaptive immune system are currently unexplored. Here we show that adaptive immune responses participate in the normal postnatal development of a non-lymphoid epithelial tissue. Since the mammary gland is the only organ developing predominantly after birth, we utilized it as a powerful system to study (...) adaptive immune regulation of organogenesis. We found that antigen-mediated interactions between mammary antigen-presenting cells and interferon-γ -producing CD4+ T helper 1 cells participate in MG postnatal organogenesis as negative regulators, locally orchestrating epithelial rearrangement. IFNγ then affects luminal lineage differentiation. This function of adaptive immune responses, regulating normal development, changes the paradigm for studying players of postnatal organogenesis and provides insights into immune surveillance and cancer transformation. Plaks et al. (shrink)

BACKGROUND: Serotonin transporter promoter genotype appears to increase risk for depression in the context of stressful life events. However, the effects of this genotype on measures of stress sensitivity are poorly understood. Therefore, this study examined whether 5-HTTLPR genotype was associated with negative information processing biases in early childhood. METHOD: Thirty-nine unselected seven-year-old children completed a negative mood induction procedure and a Self-Referent Encoding Task designed to measure positive and negative schematic processing. Children were also genotyped for the 5-HTTLPR gene. (...) RESULTS: Children who were homozygous for the short allele of the 5-HTTLPR gene showed greater negative schematic processing following a negative mood prime than those with other genotypes. 5-HTTLPR genotype was not significantly associated with positive schematic processing. LIMITATIONS: The sample size for this study was small. We did not analyze more recently reported variants of the 5-HTTLPR long alleles. CONCLUSIONS: 5-HTTLPR genotype is associated with negative information processing styles following a negative mood prime in a non-clinical sample of young children. Such cognitive styles are thought to be activated in response to stressful life events, leading to depressive symptoms; thus, cognitive styles may index the "stress-sensitivity" conferred by this genotype. (shrink)

OBJECTIVES: Early-emerging, temperamental differences in fear-related traits may be a heritable vulnerability factor for anxiety disorders. Previous research indicates that the serotonin transporter promoter region polymorphism is a candidate gene for such traits. METHODS: Associations between 5-HTTLPR genotype and indices of fearful child temperament, derived from maternal report and standardized laboratory observations, were examined in a community sample of 95 preschool-aged children. RESULTS: Children with one or more long alleles of the 5-HTTLPR gene were rated as significantly more nervous during (...) standardized laboratory tasks than children who were homozygous for the short alleles. Children homozygous for the short alleles were also rated as significantly shyer, by maternal report, than those with at least one copy of the long allele of the 5-HTTLPR gene. CONCLUSIONS: This study extends the literature linking the short alleles of the serotonin transporter promoter region polymorphism to fear and anxiety-related traits in early childhood and adulthood, and is one of very few studies to examine the molecular genetics of preschoolers' temperament using multiple measures of traits in a normative sample. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Acts of Enjoyment: Rhetoric, Žižek, and the Return of the SubjectJames J. Brown Jr. and Joshua GunnActs of Enjoyment: Rhetoric, Žižek, and the Return of the Subject by Thomas Rickert. Pittsburgh: University of Pittsburgh Press, 2007. Pp. x + 252. $24.95, hardcover.Thomas Rickert had a falling-out with his brother, and this distresses him so much that his disrupted relation is described as “traumatic.” Rickert reports that while listening (...) to a portable CD player during a run on an unexpectedly warm winter day, a song by the now defunct jazz/rock band Morphine reminded him of a happy time at a pool hall with his brother (24). Mediated—or better, medicated—by music, the homological happiness of running in the sun and a positive past memory also resurfaced a painful relational rupture, the reason of which Rickert omits to underscore that mysterious, “little detail or object” of the Real that marks his singular finitude as a writing subject (216 n. 11). We’ll want to come back to this curiously deliberate omission, but for the present we note Rickert is not simply an undead author but a human being with relations and feelings. He is not just a gifted scholar or a bundle of reflections, but a nexus of body and movement and words and affect. If there is anything that Rickert’s study can be said to work through with brilliance, humor, and grace, it is the reality of complex personhood.Rickert’s brotherly confession comes in Chapter 1 as a way to introduce a psychoanalytic understanding of subjectivity, and more specifically, to help illustrate how trauma works itself out as an afterwardness or “belatedness” ( Nachträglichkeit ): traumatic events from the past are not reckoned with or worked-through until some coincidence or reminder, such as a similar [End Page 183] sensory experience, reintroduces the event in doubled re-presentation (18–27). This implies the “subject” (a paradigm person) is a kind of timedelay, a self-conscious temporal moving that becomes this way through re-presentation. The rhetorical subject is analogously a retrojected reckoning with events past (not all traumatic) that Rickert identifies as a scene of writing, a locus that has important implications for rhetorical studies in general and writing pedagogy in particular. Rickert’s logic is as follows: if we agree that the subject is a belated one in the psychoanalytic sense, then how we teach rhetoric needs to change. Rickert opens the book with the observation that his students are producing excellent cultural critiques but that such critiques do not lead the students to change their actions (1–7), perhaps evidence enough that something is not quite right in a classroom grounded by “cultural studies pedagogy” and ideology critique—or at the very least, proof that something has changed. The opening gambit is simply that a “postpedagogy” premised on an understanding of rhetorical subjectivity as belatedness is better than a status quo rooted in the rational subject of the Enlightenment.Mostly through a Žižek-filtered, Lacanian lens, Acts of Enjoyment then undertakes a retake of the rhetorical field, frequently scanning from the traumatic ontology of the rhetorical subject to that domain of knowledge that we hold dear, the subject of rhetoric. In Chapter 2, the (primal) scene thus shifts from the slo-mo subject to rhetorical studies, initially through a reassessment of Kinneavy’s “communications triangle,” but ultimately in response to the shock treatment of poststructuralism. The initial theoretical traumas introduced by Victor Vitanza, Diane Davis, Sharon Crowley, and others discussed in Chapter 1 are threaded into an account of “poststructural” redress in Chapter 2: as is true of all forms of trauma, the initial poststructural jolt delivered to the concept of subjectivity was deadened; poststructural theory was eventually used to “shore up rather than challenge Kinneavy’s triangle” (37). To truly work-through our traumatized subject in both senses, we need a second trauma: Lacanian psychoanalysis. Presumably, “poststructuralist thought” is to be opposed because it has no account of the subject (21–24); “Lacan,” after all, “is not a poststructuralist” (48). The remainder of the chapter is then used to deploy Lacan’s conceptual lexicon.Just as... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Acts of Enjoyment: Rhetoric, Žižek, and the Return of the SubjectJames J. Brown Jr. and Joshua GunnActs of Enjoyment: Rhetoric, Žižek, and the Return of the Subject by Thomas Rickert. Pittsburgh: University of Pittsburgh Press, 2007. Pp. x + 252. $24.95, hardcover.Thomas Rickert had a falling-out with his brother, and this distresses him so much that his disrupted relation is described as “traumatic.” Rickert reports that while listening (...) to a portable CD player during a run on an unexpectedly warm winter day, a song by the now defunct jazz/rock band Morphine reminded him of a happy time at a pool hall with his brother (24). Mediated—or better, medicated—by music, the homological happiness of running in the sun and a positive past memory also resurfaced a painful relational rupture, the reason of which Rickert omits to underscore that mysterious, “little detail or object” of the Real that marks his singular finitude as a writing subject (216 n. 11). We’ll want to come back to this curiously deliberate omission, but for the present we note Rickert is not simply an undead author but a human being with relations and feelings. He is not just a gifted scholar or a bundle of reflections, but a nexus of body and movement and words and affect. If there is anything that Rickert’s study can be said to work through with brilliance, humor, and grace, it is the reality of complex personhood.Rickert’s brotherly confession comes in Chapter 1 as a way to introduce a psychoanalytic understanding of subjectivity, and more specifically, to help illustrate how trauma works itself out as an afterwardness or “belatedness” ( Nachträglichkeit ): traumatic events from the past are not reckoned with or worked-through until some coincidence or reminder, such as a similar [End Page 183] sensory experience, reintroduces the event in doubled re-presentation (18–27). This implies the “subject” (a paradigm person) is a kind of timedelay, a self-conscious temporal moving that becomes this way through re-presentation. The rhetorical subject is analogously a retrojected reckoning with events past (not all traumatic) that Rickert identifies as a scene of writing, a locus that has important implications for rhetorical studies in general and writing pedagogy in particular. Rickert’s logic is as follows: if we agree that the subject is a belated one in the psychoanalytic sense, then how we teach rhetoric needs to change. Rickert opens the book with the observation that his students are producing excellent cultural critiques but that such critiques do not lead the students to change their actions (1–7), perhaps evidence enough that something is not quite right in a classroom grounded by “cultural studies pedagogy” and ideology critique—or at the very least, proof that something has changed. The opening gambit is simply that a “postpedagogy” premised on an understanding of rhetorical subjectivity as belatedness is better than a status quo rooted in the rational subject of the Enlightenment.Mostly through a Žižek-filtered, Lacanian lens, Acts of Enjoyment then undertakes a retake of the rhetorical field, frequently scanning from the traumatic ontology of the rhetorical subject to that domain of knowledge that we hold dear, the subject of rhetoric. In Chapter 2, the (primal) scene thus shifts from the slo-mo subject to rhetorical studies, initially through a reassessment of Kinneavy’s “communications triangle,” but ultimately in response to the shock treatment of poststructuralism. The initial theoretical traumas introduced by Victor Vitanza, Diane Davis, Sharon Crowley, and others discussed in Chapter 1 are threaded into an account of “poststructural” redress in Chapter 2: as is true of all forms of trauma, the initial poststructural jolt delivered to the concept of subjectivity was deadened; poststructural theory was eventually used to “shore up rather than challenge Kinneavy’s triangle” (37). To truly work-through our traumatized subject in both senses, we need a second trauma: Lacanian psychoanalysis. Presumably, “poststructuralist thought” is to be opposed because it has no account of the subject (21–24); “Lacan,” after all, “is not a poststructuralist” (48). The remainder of the chapter is then used to deploy Lacan’s conceptual lexicon.Just as... (shrink)

Bu makale, sosyal dışlanma kavramına genel bir bakış sağlar. Kavramın önem kazandığı belirli tarihsel durumları yeniden ele alır. Ayrıca kavramın, belli başlı okumalarını destekleyen farklı teorik çerçeveleri saptadığı gibi, çeşitli yorumlamaları da ele alır.This article provides a general overview ofthe concept of social exclusion. It reconstructs the specific historical conditions in which the concept gained prominence. Furthermore, it identifies the various interpretations as well as the different theoretical frameworks that underpin the distinctive reading ofthe concept.