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This paper develops a structural model of newspaper markets to analyze the effects of ownership consolidation, taking into account not only firms' price adjustments but also the adjustments in newspaper characteristics. A new dataset on newspaper prices and characteristics is used to estimate the model. The paper then simulates the effect of a merger in the Minneapolis newspaper market and studies how welfare effects of mergers vary with market characteristics. It finds that ignoring adjustments of product characteristics causes substantial differences in estimated effects of mergers.

Vegetation modulates Earth’s water, energy and carbon cycles. How its functions might change in the future largely depends on how it copes with droughts 1 – 4 . There is evidence that, in places and times of drought, vegetation shifts water uptake to deeper soil 5 – 7 and rock 8 , 9 moisture as well as groundwater 10 – 12 . Here we differentiate and assess plant use of four types of water sources: precipitation in the current month (source 1), past precipitation stored in deeper unsaturated soils and/or rocks (source 2), past precipitation stored in groundwater (source 3, locally recharged) and groundwater from precipitation fallen on uplands via river–groundwater convergence toward lowlands (source 4, remotely recharged). We examine global and seasonal patterns and drivers in plant uptake of the four sources using inverse modelling and isotope-based estimates. We find that (1), globally and annually, 70% of plant transpiration relies on source 1, 18% relies on source 2, only 1% relies on source 3 and 10% relies on source 4; (2) regionally and seasonally, source 1 is only 19% in semi-arid, 32% in Mediterranean and 17% in winter-dry tropics in the driest months; and (3) at landscape scales, source 2, taken up by deep roots in the deep vadose zone, is critical in uplands in dry months, but source 4 is up to 47% in valleys where riparian forests and desert oases are found. Because the four sources originate from different places and times, move at different spatiotemporal scales and respond with different sensitivity to climate and anthropogenic forces, understanding the space and time origins of plant water sources can inform ecosystem management and Earth system models on the critical hydrological pathways linking precipitation to vegetation. Global inverse modelling of plant water acquisition depth and isotope-based plant water use estimates demonstrate globally prevalent use of precipitation from distant sources, and that water-stressed ecosystems are well suited to using past and remote precipitation.

In General Relativity, addressing coupling to a non-linear electromagnetic field, together with a negative cosmological constant, we obtain the general static spherical symmetric black hole solution with magnetic charges, which is asymptotic to anti-de Sitter (AdS) space-times. In particular, for a degenerate case the solution becomes a Hayward–AdS black hole, which is regular everywhere in the full space-time. The existence of such a regular black hole solution preserves the weak energy condition, while the strong energy condition is violated. We then derive the first law and the Smarr formula of the black hole solution. We further discuss its thermodynamic properties and study the critical phenomena in the extended phase space where the cosmological constant is treated as a thermodynamic variable as well as the parameter associated with the non-linear electrodynamics. We obtain many interesting results such as: the Maxwell equal area law in the P - V (or S - T ) diagram is violated and consequently the critical point ( T ∗ , P ∗ ) of the first order small–large black hole transition does not coincide with the inflection point ( T c , P c ) of the isotherms; the Clapeyron equation describing the coexistence curve of the Van der Waals (vdW) fluid is no longer valid; the heat capacity at constant pressure is finite at the critical point; the various exponents near the critical point are also different from those of the vdW fluid.

A bstract The physical relevance of the thermodynamic volumes of AdS black holes to the gravity duals of quantum complexity was recently argued by Couch et al. In this paper, by generalizing the Wald-Iyer formalism, we derive a geometric expression for the thermodynamic volume and relate its product with the thermodynamic pressure to the non-derivative part of the gravitational action evaluated on the Wheeler-DeWitt patch. We propose that this action provides an alternative gravity dual of the quantum complexity of the boundary theory. We refer this to “complexity=action 2.0” (CA-2) duality. It is significantly different from the original “complexity=action” (CA) duality as well as the “complexity=volume 2.0” (CV-2) duality proposed by Couch et al. The latter postulates that the complexity is dual to the spacetime volume of the Wheeler-DeWitt patch. To distinguish our new conjecture from the various dualities in literature, we study a number of black holes in Einstein-Maxwell-Dilation theories. We find that for all these black holes, the CA duality generally does not respect the Lloyd bound whereas the CV-2 duality always does. For the CA-2 duality, although in many cases it is consistent with the Lloyd bound, we also find a counter example for which it violates the bound as well.

A bstract We study upper bounds on the growth of operator entropy S K in operator growth. Using uncertainty relation, we first prove a dispersion bound on the growth rate |∂ t S K | ≤ 2 b 1 ∆ S K , where b 1 is the first Lanczos coefficient and ∆ S K is the variance of S K . However, for irreversible process, this bound generally turns out to be too loose at long times. We further find a tighter bound in the long time limit using a universal logarithmic relation between Krylov complexity and operator entropy. The new bound describes the long time behavior of operator entropy very well for physically interesting cases, such as chaotic systems and integrable models.

We study the contributions for the K + K - and K 0 K ¯ 0 originating from the intermediate states ϕ ( 1020 ) and ϕ ( 1680 ) in the charmless three-body decays B → K K ¯ h , with h = ( π , K ) , in the perturbative QCD approach. The subprocesses ϕ ( 1020 , 1680 ) → K K ¯ are introduced into the distribution amplitudes of K K ¯ system via the kaon electromagnetic form factors with the coefficients taken from the fitted results. The predictions of the branching fractions for the decays B → ϕ ( 1680 ) h with the intermediate state ϕ ( 1680 ) decays into K + K - or K 0 K ¯ 0 are about 6 - 8 % of the corresponding results for the quasi-two-body decays B → ϕ ( 1020 ) h → K + K - h in this work.

Background To investigate the resilience of non-local medical workers sent to support local medical workers in treating the outbreak of 2019 novel coronavirus disease (COVID-19). Methods In February 2020, non-local medical workers who had been sent to Wuhan as support staff to respond to the COVID-19 outbreak were asked to complete an online survey composed of the Connor Davidson Resilience Scale (CD-RISC), Hospital Anxiety Depression Scale (HADS) and Simplified Coping Style Questionnaire (SCSQ). Results Survey responses from 114 non-local medical workers were analyzed. CD-RISC scores were high (67.03 ± 13.22). The resilience level was highest for physicians (73.48 ± 11.49), followed by support staff, including health care assistants, technicians (67.78 ± 12.43) and nurses (64.86 ± 13.46). Respondents differed significantly in the levels of education, training/support provided by the respondent’s permanent hospital (where he or she normally works), and in their feelings of being adequately prepared and confident to complete tasks ( P  < 0.05). Resilience correlated negatively with anxiety ( r  = −.498, P  < 0.01) and depression ( r  = −.471, P  < 0.01) but positively with active coping styles ( r  = .733, P  < 0.01). Multiple regression analysis showed that active coping ( β  = 1.314, p  < 0.05), depression ( β  = −.806, p  < 0.05), anxiety ( β  = − 1.091, p  < 0.05), and training/support provided by the respondent’s permanent hospital ( β  = 3.510, p  < 0.05) were significant associated with resilience. Conclusion Our data show that active coping, depression, anxiety, and training/support provided by the respondent’s permanent hospital are associated with resilience. Managers of medical staff should use these data to develop psychosocial interventions aimed at reinforcing the resilience of medical workers during highly stressful and prolonged medical emergencies, as seen during the COVID-19 outbreak.

Background The purpose of this study was to design a customized fixation plate for mandibular angle fracture using topological optimization based on the biomechanical properties of the two conventional fixation systems, and compare the results of stress, strain and displacement distributions calculated by finite element analysis (FEA). Methods A three-dimensional (3D) virtual mandible was reconstructed from CT images with a mimic angle fracture and a 1 mm gap between two bone segments, and then a FEA model, including volume mesh with inhomogeneous bone material properties, three loading conditions and constraints (muscles and condyles), was created to design a customized plate using topological optimization method, then the shape of the plate was referenced from the stress concentrated area on an initial part created from thickened bone surface for optimal calculation, and then the plate was formulated as “V” pattern according to dimensions of standard mini-plate finally. To compare the biomechanical behavior of the “V” plate and other conventional mini-plates for angle fracture fixation, two conventional fixation systems were used: type A, one standard mini-plate, and type B, two standard mini-plates, and the stress, strain and displacement distributions within the three fixation systems were compared and discussed. Results The stress, strain and displacement distributions to the angle fractured mandible with three different fixation modalities were collected, respectively, and the maximum stress for each model emerged at the mandibular ramus or screw holes. Under the same loading conditions, the maximum stress on the customized fixation system decreased 74.3, 75.6 and 70.6% compared to type A, and 34.9, 34.1, and 39.6% compared to type B. All maximum von Mises stresses of mandible were well below the allowable stress of human bone, as well as maximum principal strain. And the displacement diagram of bony segments indicated the effect of treatment with different fixation systems. Conclusions The customized fixation system with topological optimized structure has good biomechanical behavior for mandibular angle fracture because the stress, strain and displacement within the plate could be reduced significantly comparing to conventional “one mini-plate” or “two mini-plates” systems. The design methodology for customized fixation system could be used for other fractures in mandible or other bones to acquire better mechanical behavior of the system and improve stable environment for bone healing. And together with SLM, the customized plate with optimal structure could be designed and fabricated rapidly to satisfy the urgent time requirements for treatment.

Nation branding and nation brand are two different concepts. A nation has a brand image with or without nation branding. This paper examines the concept of nation branding, focusing on the central question of what is being branded. It differentiates nation branding from product branding, and draws comparisons between nation branding and productcountry image. Paradoxical issues around the concept and the wider context in which nation branding can be applied are also discussed. More research is needed to find out if and how nation branding could help economic development in a country. As many other non-marketing factors also affect a nation's image, the role played by nation branding may turn out to be only a modest one.