X-ray free-electron lasers enable the investigation of the structure and dynamics of diverse systems, including atoms, molecules, nanocrystals and single bioparticles, under extreme conditions. Many ...imaging applications that target biological systems and complex materials use hard X-ray pulses with extremely high peak intensities (exceeding 10
watts per square centimetre). However, fundamental investigations have focused mainly on the individual response of atoms and small molecules using soft X-rays with much lower intensities. Studies with intense X-ray pulses have shown that irradiated atoms reach a very high degree of ionization, owing to multiphoton absorption, which in a heteronuclear molecular system occurs predominantly locally on a heavy atom (provided that the absorption cross-section of the heavy atom is considerably larger than those of its neighbours) and is followed by efficient redistribution of the induced charge. In serial femtosecond crystallography of biological objects-an application of X-ray free-electron lasers that greatly enhances our ability to determine protein structure-the ionization of heavy atoms increases the local radiation damage that is seen in the diffraction patterns of these objects and has been suggested as a way of phasing the diffraction data. On the basis of experiments using either soft or less-intense hard X-rays, it is thought that the induced charge and associated radiation damage of atoms in polyatomic molecules can be inferred from the charge that is induced in an isolated atom under otherwise comparable irradiation conditions. Here we show that the femtosecond response of small polyatomic molecules that contain one heavy atom to ultra-intense (with intensities approaching 10
watts per square centimetre), hard (with photon energies of 8.3 kiloelectronvolts) X-ray pulses is qualitatively different: our experimental and modelling results establish that, under these conditions, the ionization of a molecule is considerably enhanced compared to that of an individual heavy atom with the same absorption cross-section. This enhancement is driven by ultrafast charge transfer within the molecule, which refills the core holes that are created in the heavy atom, providing further targets for inner-shell ionization and resulting in the emission of more than 50 electrons during the X-ray pulse. Our results demonstrate that efficient modelling of X-ray-driven processes in complex systems at ultrahigh intensities is feasible.
The revolution in information availability and the advances in novel interaction technologies have ushered in two major shifts that call into question the traditional assumptions of buyer–seller ...interactions. First, buyer–seller
information asymmetry
has greatly decreased in many interactions. Second, face-to-face communication is no longer the main format of buyer–seller interactions. In this article, the authors review empirical research on how these shifts have changed buyer–seller negotiations, an important type of buyer–seller interactions. Several insights arise from this review. First, the shifts have caused fundamental changes in buyers’ and sellers’ roles, power, and aspirations and information processing. Second, the shifts and these fundamental changes together cause major changes in buyer–seller interactional processes and outcomes, including (1) change in buyers’ attitude and behavior, (2) change in sellers’ effectiveness in interacting with buyers, and (3) change in buyer–seller interactional processes. Based on these insights, the authors develop a research agenda to guide the reexamination of existing theories and the development of new theories of buyer–seller interactions.
This article reconciles mixed findings about the performance impact of middle managers' strategy involvement. We propose that the relationship between middle managers' adaptive strategy ...implementation—through upward and downward influence—and objective business performance can be curvilinear and contingent on formal and informal structures. Applying a multilevel perspective to social networks, we empirically show that reputational social capital enhances the performance impact of middle managers' upward influence while informational social capital elevates the performance impact of their downward influence. The size of a business unit or region has differntial moderating effects. The curvilinear effects of middle managers' upward influence and reputational and informational social capital on business unit performance reflect paradoxes. We discuss the implications of these findings for strategy implementation research and practice.
There has been little research on how market disruptions affect customer—brand relationships and how firms can sustain brand loyalty when disruptions occur. Drawing from social identity theory and ...the brand loyalty literature, the authors propose a conceptual framework to examine these issues in a specific market disruption, namely, the introduction of a radically new brand. The framework focuses on the time-varying effects of customers' identification with and perceived value of the incumbent relative to the new brand on switching behavior. The authors divert from the conventional economic perspective of treating brand switching as functional utility maximization to propose that brand switching can also result from customers' social mobility between brand identities. The results from longitudinal data of 679 customers during the launch of the iPhone in Spain show that both relative customer—brand identification and relative perceived value of the incumbent inhibit switching behavior, but their effects vary over time. Relative customer—brand identification with the incumbent apparently exerts a stronger longitudinal restraint on switching behavior than relative perceived value of the incumbent. The study has important strategic implications for devising customer relationship strategies and brand investment.
Low-dose organochlorine (OC) pesticides have recently been associated with type 2 diabetes in several non-Asian general populations. As there is currently epidemic type 2 diabetes in Asia, we ...investigated the associations between OC pesticides and type 2 diabetes in Koreans. Among subjects who participated in a community-based health survey, we randomly selected 40 diabetic patients and 40 normal controls. Ten OC pesticides (beta-hexachlorocyclohexane, hexachlorobenzene, heptachlor epoxide, p,p′-DDE, p,p′-DDD, p,p′-DDT, o,p′-DDT, oxychlordane, trans-nonachlor, and mirex) detectable in ≥
70% of controls were analyzed in relation to diabetes. Most OC pesticides showed strong associations with type 2 diabetes after adjusting for age, sex, BMI, alcohol consumption, and cigarette smoking. Compared with subjects in the lowest tertile of each OC pesticide, adjusted odds ratios (ORs) in the 3rd tertile ranged from 3.1 (95% CI 0.8–12.1) for heptachlor epoxide to 26.0 (95% CI 1.3–517.4) for oxychlordane. In the case of chemicals belonging to the DDT family, adjusted ORs in the 3rd tertile were in the range of 10.6 (95% CI 1.3–84.9) for p,p′-DDT to 12.7 (95% CI 1.9–83.7) for p,p′-DDE. In this exploratory study with small sample, low-dose background exposure to OC pesticides was strongly associated with prevalent type 2 diabetes in Koreans even though absolute concentrations of OC pesticides were no higher than in other populations. Asians may be more susceptible to adverse effects of OC pesticides than other races.
We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and ...identified that Xe(n+) with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n≥24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers.
This study examines the dynamics of consumer–brand identification (CBI) and its antecedents in the context of the launch of a new brand. Three focal drivers of CBI with a new brand are examined, ...namely: perceived quality (the instrumental driver), self–brand congruity (the symbolic driver), and consumer innate innovativeness (a trait-based driver). Using longitudinal survey data, the authors find that on average, CBI growth trajectories initially rise after the introduction but eventually decline, following an inverted-U shape. More importantly, the longitudinal effects of the antecedents suggest that CBI can take different paths. Consumer innovativeness creates a fleeting identification with the brand that dissipates over time. On the other hand, company-controlled drivers of CBI—such as brand positioning—can contribute to the build-up of deep-structure CBI that grows stronger over time. Based on these findings, the authors offer normative guidelines to managers on consumer–brand relationship investment.
Abstract
The discovery of two-dimensional magnets has initiated a new field of research, exploring both fundamental low-dimensional magnetism, and prospective spintronic applications. Recently, ...observations of magnetic skyrmions in the 2D ferromagnet Fe
3
GeTe
2
(FGT) have been reported, introducing further application possibilities. However, controlling the exhibited magnetic state requires systematic knowledge of the history-dependence of the spin textures, which remains largely unexplored in 2D magnets. In this work, we utilise real-space imaging, and complementary simulations, to determine and explain the thickness-dependent magnetic phase diagrams of an exfoliated FGT flake, revealing a complex, history-dependent emergence of the uniformly magnetised, stripe domain and skyrmion states. The results show that the interplay of the dominant dipolar interaction and strongly temperature dependent out-of-plane anisotropy energy terms enables the selective stabilisation of all three states at zero field, and at a single temperature, while the Dzyaloshinksii-Moriya interaction must be present to realise the observed Néel-type domain walls. The findings open perspectives for 2D devices incorporating topological spin textures.
Using electron spectroscopy, we have investigated nanoplasma formation from noble gas clusters exposed to high-intensity hard-x-ray pulses at ~5 keV. Our experiment was carried out at the SPring-8 ...Angstrom Compact free electron LAser (SACLA) facility in Japan. Dedicated theoretical simulations were performed with the molecular dynamics tool XMDYN. We found that in this unprecedented wavelength regime nanoplasma formation is a highly indirect process. In the argon clusters investigated, nanoplasma is mainly formed through secondary electron cascading initiated by slow Auger electrons. Energy is distributed within the sample entirely through Auger processes and secondary electron cascading following photoabsorption, as in the hard x-ray regime there is no direct energy transfer from the field to the plasma. This plasma formation mechanism is specific to the hard-x-ray regime and may, thus, also be important for XFEL-based molecular imaging studies. In xenon clusters, photo- and Auger electrons contribute more significantly to the nanoplasma formation. Good agreement between experiment and simulations validates our modelling approach. This has wide-ranging implications for our ability to quantitatively predict the behavior of complex molecular systems irradiated by high-intensity hard x-rays.
Drawing from the interactional psychology of personality and multitasking paradigm, we examine the contingencies of salesperson orientation ambidexterity in the “exploration” of new customers (i.e., ...hunting) and the “exploitation” of existing customers (i.e., farming) to achieve sales growth and make time allocation decisions. The results from a field study and an experiment indicate that the impact of salesperson orientation ambidexterity is contingent on a salesperson’s customer base characteristics. First, a salesperson’s orientation ambidexterity in both hunting and farming leads to significantly higher (lower) sales growth when his or her existing customer base is large (small). Second, high levels of customer base newness in a salesperson’s customer portfolio weaken the relationship between hunting time allocation at time t – 1 and hunting time allocation at time t, suggesting that salespeople are not subject to a success trap in hunting. However, salespeople are subject to a success trap in farming. These findings shed new light on how a salesperson’s customer portfolio influences salesperson behaviors and performance, with implications for how to better manage ambidextrous behaviors in customer engagement.
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