Spin-density-wave instability in graphene doped near the van Hove singularity

We study the instability of the metallic state towards the formation of a new ground state in graphene doped near the van Hove singularity. The system is described by the Hubbard model and a field theoretical approach is used to calculate the charge and spin susceptibility. We find that for repulsive interactions, within the random phase approximation, there is a competition between ferromagnetism and spin-density wave (SDW). It turns out that a SDW with a triangular geometry is more favorable when the Hubbard parameter is above the critical value U_c(T), which depends on the temperature T, even if there are small variations in the doping. Our results can be verified by ARPES or neutron scattering experiments in highly doped graphene.Comment: 5 pages, 5 figures, 1 tabl

Эндопротезирование плечевого сустава при опухолях проксимального отдела плечевой кости

У 25 хворих з ураженням пухлинами проксимального відділу плечової кістки вивчені функціональні результати ендопротезування плечового суглоба залежно від збереження або резекції нервово- м’язового механізму відведення і згинання плеча. Ендопротезування при збереженому механізмі відведення плеча дає високий функціональний результат (85.5±1.65%) і виконує переважно косметичну функцію, коли механізм відведення плеча не зберігається (функція відповідає 63.7±1.28%).Functional results of humoral joints endoprosthetics in 25 patients with upper extremity bones tumours subject to saving or resection of shoulder drawing aside and flection neuromuscular mechanism are studied. Endoprosthetics in the case of shoulder drawing aside mechanism saving gives a high functional result (85.5±1.65%), but it executing mainly cosmetic function, in the case when mechanism of shoulder drawing aside is not saved (such function corresponds to 63.7±1.28% from a due size)

At the Heart of Policing: Emotional labor among police officers

During my work as a police officer, I encountered many emotional demanding situations in which my colleagues and I often seemed to act unfelt emotions or suppressed emotions that would better not be displayed at that particular moment. For instance, during my first weeks of duty I wondered how police officers could stay seemingly untouched while being confronted with drunk and offensive people. One colleague once told me: “I don’t take it personally, it’s part of the job and so it doesn’t frustrate me anymore”. At other times, it turned out to be proper to display empathy although this emotion was not always genuinely felt (anymore). In contrast, when interrogating a criminal I learned that sometimes acting friendly may help to acquire important information. Otherwise, unfelt emotions such as anger had to be displayed in order to correct an offender and to prevent an interaction from escalating. These anecdotes illustrate the benefits of acting emotions during the work of police officers. Moreover, emotions form an inherent part of people’s (work) lives on a daily basis. Not surprisingly, the management and display of emotions in the workplace receives considerable attention as they may influence both individual well-being and organizational outcomes. The term emotional labor was first introduced by Hochschild (1983) and refers to how employees regulate their emotions as part of the work role and the consequences of doing so. The types of emotions that a company considers appropriate to show to clients are often part of its policy and are part of the company’s socalled display rules (Ekman, 1973; Grandey, 2000). To adhere to these display rules, employees may engage in emotional labor by suppressing felt emotions or displaying emotions that are different from their genuinely experienced emotions (Hochschild, 1983). This emotion regulation technique, termed surface acting, may lead to emotional dissonance, which refers to a state of discrepancy between felt and displayed emotions. Accumulating evidence from the past three decades reveals that both surface acting and emotional dissonance are detrimental to employee well-being (cf. Ashfort & Humphrey, 1993; Mesmer-Magnus, DeChurch, & Wax, 2012; Zapf, 2002)

Location Matters: Canopy Light Responses over Spatial Scales

Plants use light as a signal to determine neighbour proximity in dense vegetation. Far-red (FR) light reflected from neighbour plants elicits an array of growth responses throughout the plant. Recently, various light quality-induced signals have been discovered that travel between organs and tissue layers. These signals share upstream and downstream components, but can have opposing effects on cell growth. The question is how plants can coordinate these spatial signals into various growth responses in remote tissues. This coordination allows plants to adapt to the environment, and understanding the underlying mechanisms could allow precision engineering of crops. To achieve this understanding, plant photobiology research will need to focus increasingly on spatial signalling at the whole-plant level