Two-Stream Instability Model With Electrons Trapped in Quadrupoles

We formulate the theory of the two-stream instability (e-cloud instability) with electrons trapped in quadrupole magnets. We show that a linear instability theory can be sensibly formulated and analyzed. The growth rates are considerably smaller than the linear growth rates for the two-stream instability in drift spaces and are close to those actually observed

Twenty Years After the Velvet Revolution: Shifts in Czech Adolescents’ Perceptions of Family, School, and Society

Families and schools are traditionally seen as substantial socialization agents forming adolescents’ social values and their views of society. Special attention is paid to the question whether the relative importance of these influences remains stable in times of major social changes. In this study, two different generations of Czech middle adolescents are compared: (a) the “post-totalitarian” generation that grew up in the last decade of the communist regime and entered adolescence during the time of rapid political and socioeconomic changes (data collected in 1995) and (b) the current generation without personal experience with the communist regime, raised in a stable democratic society (data collected in 2010). Both groups of participants (total N = 2,127, aged from 14 to 17 years) were administered an identical questionnaire. First, we examined the changes in adolescents’ perception and evaluation of the society over the last 15 years. Today’s adolescents perceive society more as a community and their future orientations are more focused on materialistic and less on environmental values. While the emotional relationship between the children and parentsremains the same, adolescents learn a somewhat different message in the family, emphasizing self-reliance. School environment is perceived more as positive and engaging than 15 years ago. Second, we predicted adolescents’ social views and values from their assessment of family and school environment. Our results show that the effect of parental values on adolescents’ value orientations is higher in the current generation. Positive school environment contributes to the development of socially responsible orientations despite the changes in society

Classification of resonance Regge trajectories and a modified Mulholland formula

We employ a simple potential model to analyse the effects which a Regge trajectory, correlating with a bound or a metastable state at zero angular momentum, has on an integral cross section. A straightforward modification of the Mulholland formula of Macek et al is proposed for more efficient separation of the resonance contribution.Comment: 4 pages, 5 figure

Three-body recombination rates near a Feshbach resonance within a two-channel contact interaction model

We calculate the three-body recombination rate into a shallow dimer in a gas of cold bosonic atoms near a Feshbach resonance using a two-channel contact interaction model. The two-channel model naturally describes the variation of the scattering length through the Feshbach resonance and has a finite effective range. We confront the theory with the available experimental data and show that the two-channel model is able to quantitatively describe the existing data. The finite effective range leads to a reduction of the scaling factor between the recombination minima from the universal value of 22.7. The reduction is larger for larger effective ranges or, correspondingly, for narrower Feshbach resonances.Comment: 9 pages, 7 figure

Low-Energy Universality in Atomic and Nuclear Physics

An effective field theory developed for systems interacting through short-range interactions can be applied to systems of cold atoms with a large scattering length and to nucleons at low energies. It is therefore the ideal tool to analyze the universal properties associated with the Efimov effect in three- and four-body systems. In this "progress report", we will discuss recent results obtained within this framework and report on progress regarding the inclusion of higher order corrections associated with the finite range of the underlying interaction.Comment: Commissioned article for Few-Body Systems, 47 pp, 16 fig

Initial Quantitative Proteomic Map of 28 Mouse Tissues Using the SILAC Mouse

Identifying the building blocks of mammalian tissues is a precondition for understanding their function. In particular, global and quantitative analysis of the proteome of mammalian tissues would point to tissue-specific mechanisms and place the function of each protein in a whole-organism perspective. We performed proteomic analyses of 28 mouse tissues using high-resolution mass spectrometry and used a mix of mouse tissues labeled via stable isotope labeling with amino acids in cell culture as a "spike-in" internal standard for accurate protein quantification across these tissues. We identified a total of 7,349 proteins and quantified 6,974 of them. Bioinformatic data analysis showed that physiologically related tissues clustered together and that highly expressed proteins represented the characteristic tissue functions. Tissue specialization was reflected prominently in the proteomic profiles and is apparent already in their hundred most abundant proteins. The proportion of strictly tissue-specific proteins appeared to be small. However, even proteins with household functions, such as those in ribosomes and spliceosomes, can have dramatic expression differences among tissues. We describe a computational framework with which to correlate proteome profiles with physiological functions of the tissue. Our data will be useful to the broad scientific community as an initial atlas of protein expression of a mammalian species

Study of astronaut capabilities to perform extravehicular maintenance and assembly functions in weightless conditions

Analysis of astronaut capabilities to perform extravehicular maintenance and assembly functions under simulated weightlessnes

Three charged particles in the continuum. Astrophysical examples

We suggest a new adiabatic approach for description of three charged particles in the continuum. This approach is based on the Coulomb-Fourier transformation (CFT) of three body Hamiltonian, which allows to develop a scheme, alternative to Born-Oppenheimer one. The approach appears as an expansion of the kernels of corresponding integral transformations in terms of small mass-ratio parameter. To be specific, the results are presented for the system $ppe$ in the continuum. The wave function of a such system is compared with that one which is used for estimation of the rate for triple reaction $p+p+e\to d+\nu,$ which take place as a step of $pp$-cycle in the center of the Sun. The problem of microscopic screening for this particular reaction is discussed

Longitudinal changes in emerging adults' attachment preferences for their mother, father, friends, and romantic partner:Focusing on the start and end of romantic relationships

Only a few studies have longitudinally explored to whom emerging adults prefer to turn to seek closeness, comfort, and security (called attachment preferences), and previous studies on attachment preferences in emerging adults have focused only on the beginning of romantic relationships but not on the end of relationships. Czech emerging adults (M = 21.47; SD = 1.48) completed the questionnaire of attachment preferences at two time points, Wave 1 (Summer 2013) and Wave 2 (Summer 2014). Latent difference score analyses revealed that emerging adults who were not in a romantic relationship in Wave 1 but started a romantic relationship between the two waves (n = 97) and those who had a romantic partner in both waves (n = 379) were both more likely to increase their attachment preference for the romantic partner and decrease their preference for friends, whereas those who did not start a relationship (n = 185) were not. Emerging adults who were in a romantic relationship in Wave 1 but were not in Wave 2 (n = 69) decreased their preference for the partner and increased their preference for friends. In all the groups, attachment preferences for the mother, for the father, or for the family did not change. Multiple regression analyses further revealed that for those who had a romantic partner in both waves, their length of romantic relationship was associated with changes in attachment preferences for romantic partners and for friends

Three particles in an external trap: Nature of the complete J=0 spectrum

Three bosonic, spin-polarized atoms in a spherical oscillator potential constitutes the simplest nontrivial Bose-Einstein condensate (BEC). The present paper develops the tools needed to understand the nature of the complete J=0 energy spectrum for this prototype system, assuming a sum of two-body potentials. The resulting spectrum is calculated as a function of the two-body scattering length a_sc, which documents the evolution of certain many-body levels that evolve from BEC-type to molecular-type as the scattering length is decreased. Implications for the behavior of the condensate excited-state spectrum and for condensate formation and decay are elucidated. The energy levels evolve smoothly, even through the regime where the number of two-body bound states N_b increases by 1, and a_{sc} switches from -infinity to infinity. We point out the possibility of suppressing three-body recombination by tuning the two-body scattering length to values that are larger than the size of the condensate ground state. Comparisons with mean-field treatments are presented