Procurement Mechanisms with Post-Auction Pre-Award Cost-Reduction Investigations

A buyer seeking to outsource production may be able to and ways to reduce a potential supplier's cost, e.g., by suggesting improvements to the supplier's proposed production methods. We study how a buyer could use such \cost-reduction investigations" by proposing a three-step supplier selection mechanism: First, each of several potential suppliers submits a price bid for a contract. Second, for each potential supplier, the buyer can exert an effort to see if she can identify how the supplier could reduce his cost to perform the contract; the understanding is that if savings are found, they are passed on to the buyer if the supplier is awarded the contract. Third, the buyer awards the contract to whichever supplier has the lowest updated bid (the supplier's initial bid price minus any cost-reduction the buyer was able to identify for that supplier). For this proposed process, we characterize how the buyer's decision on which suppliers to investigate cost reductions for in step 2 is affected by the aggressiveness of the suppliers' bids in step 1. We show that even if the buyer does not share the cost savings she identifies in step 2, ex ante symmetric suppliers are actually better off (ex ante) in our proposed mechanism than in a setting without such cost-reduction investigations, resulting in a win-win for the buyer and suppliers. When suppliers' cost and cost-reduction distributions become very heterogeneous, the win-win situation may no longer hold, but every supplier still has an incentive to allow the buyer to investigate him in step 2 because it increases his chance of winning the contract. Using an optimal mechanism analysis, our numerical studies show that our proposed Bid-Investigate-Award mechanism helps the buyer achieve near-optimal performance, despite its simplicity

Tidal tensors in the description of gravity and electromagnetism

In 2008-2009, F. Costa and C. Herdeiro proposed a new gravito-electromagnetic analogy, based on tidal tensors. We show that connections on the tangent bundle of the space-time manifold can help not only in finding a covnenient geometrization of their ideas, but also a common mathematical description of the main equations of gravity and electromagnetism.Comment: submitted to: Journal of Nonlinear Mathematical Physic

When to Deploy Test Auctions in Sourcing

We investigate when a buyer seeking to procure multiple units of an input may find it advantageous to run a “test auction” in which she has incumbent suppliers bid on a portion of the desired units. The test auction reveals incumbent supplier cost information that helps the buyer determine how many entrants (if any) to recruit at a cost prior to awarding the remaining units. The optimal number of entrant suppliers to recruit follows a threshold policy that is monotonic in the test auction’s clearing price unless the underlying supplier cost distribution is not regular. When setting her reserve price in the test auction, the buyer uses supplier recruitment as her “outside option”: if the reserve price is not met in the test auction, the buyer recruits new suppliers and runs a second auction. We compare the attractiveness of the test auction procedure relative to the more conventional procedure in which the buyer auctions off her entire demand in one auction. Since the buyer can choose ex ante which procedure to use, we propose using whichever has lower ex ante total (purchase plus recruitment) cost. Finally, using an optimal mechanism analysis, we find a lower bound on the buyer’s cost, and use that cost as a benchmark to show that our proposed sourcing strategy performs well given its ease of implementation

Pygmy dipole strength close to particle-separation energies - the case of the Mo isotopes

The distribution of electromagnetic dipole strength in 92, 98, 100 Mo has been investigated by photon scattering using bremsstrahlung from the new ELBE facility. The experimental data for well separated nuclear resonances indicate a transition from a regular to a chaotic behaviour above 4 MeV of excitation energy. As the strength distributions follow a Porter-Thomas distribution much of the dipole strength is found in weak and in unresolved resonances appearing as fluctuating cross section. An analysis of this quasi-continuum - here applied to nuclear resonance fluorescence in a novel way - delivers dipole strength functions, which are combining smoothly to those obtained from (g,n)-data. Enhancements at 6.5 MeV and at ~9 MeV are linked to the pygmy dipole resonances postulated to occur in heavy nuclei.Comment: 6 pages, 5 figures, proceedings Nuclear Physics in Astrophysics II, May 16-20, Debrecen, Hungary. The original publication is available at www.eurphysj.or

The D9N, N291S and S447X variants in the lipoprotein lipase (LPL) gene are not associated with Type III Hyperlipidemia

<p>Abstract</p> <p>Background</p> <p>Type III hyperlipidemia (Type III HLP) is associated with homozygosity for the ε2 allele of the APOE gene. However only about 10% of ε2 homozygotes develop Type III HLP and it is assumed that additional genetic and/or environmental factors are required for its development. Common variants in the LPL gene have been proposed as likely genetic co-factors.</p> <p>Methods</p> <p>The frequency of the LPL SNPs D9N, N291S and S447X in 100 patients with hyperlipidemia and APOE2/2 genotype has been determined and compared to that in healthy blood donors and patients with hyperlipidemia.</p> <p>Results</p> <p>There were no statistically significant difference in the frequencies of the variants between APOE2/2 patients and controls.</p> <p>Conclusion</p> <p>It is unlikely that the D9N, N291S or S447X variants in the LPL gene play an important role in the development of Type III HLP.</p

Nonlinear response of a driven vibrating nanobeam in the quantum regime

We analytically investigate the nonlinear response of a damped doubly clamped nanomechanical beam under static longitudinal compression which is excited to transverse vibrations. Starting from a continuous elasticity model for the beam, we consider the dynamics of the beam close to the Euler buckling instability. There, the fundamental transverse mode dominates and a quantum mechanical time-dependent effective single particle Hamiltonian for its amplitude can be derived. In addition, we include the influence of a dissipative Ohmic or super-Ohmic environment. In the rotating frame, a Markovian master equation is derived which includes also the effect of the time-dependent driving in a non-trivial way. The quasienergies of the pure system show multiple avoided level crossings corresponding to multiphonon transitions in the resonator. Around the resonances, the master equation is solved analytically using Van Vleck perturbation theory. Their lineshapes are calculated resulting in simple expressions. We find the general solution for the multiple multiphonon resonances and, most interestingly, a bath-induced transition from a resonant to an antiresonant behavior of the nonlinear response.Comment: 25 pages, 5 figures, submitted to NJ

The effective force NL3 revisited

Covariant density functional theory based on the relativistic mean field (RMF) Lagrangian with the parameter set NL3 has been used in the last ten years with great success. Now we propose a modification of this parameter set, which improves the description of the ground state properties of many nuclei and simultaneously provides an excellent description of excited states with collective character in spherical as well as in deformed nuclei.Comment: 8 pages, 5 figure

Noninvasive ventilation in COVID-19 patients aged ≥ 70 years-a prospective multicentre cohort study.

BACKGROUND Noninvasive ventilation (NIV) is a promising alternative to invasive mechanical ventilation (IMV) with a particular importance amidst the shortage of intensive care unit (ICU) beds during the COVID-19 pandemic. We aimed to evaluate the use of NIV in Europe and factors associated with outcomes of patients treated with NIV. METHODS This is a substudy of COVIP study-an international prospective observational study enrolling patients aged ≥ 70 years with confirmed COVID-19 treated in ICU. We enrolled patients in 156 ICUs across 15 European countries between March 2020 and April 2021.The primary endpoint was 30-day mortality. RESULTS Cohort included 3074 patients, most of whom were male (2197/3074, 71.4%) at the mean age of 75.7 years (SD 4.6). NIV frequency was 25.7% and varied from 1.1 to 62.0% between participating countries. Primary NIV failure, defined as need for endotracheal intubation or death within 30 days since ICU admission, occurred in 470/629 (74.7%) of patients. Factors associated with increased NIV failure risk were higher Sequential Organ Failure Assessment (SOFA) score (OR 3.73, 95% CI 2.36-5.90) and Clinical Frailty Scale (CFS) on admission (OR 1.46, 95% CI 1.06-2.00). Patients initially treated with NIV (n = 630) lived for 1.36 fewer days (95% CI - 2.27 to - 0.46 days) compared to primary IMV group (n = 1876). CONCLUSIONS Frequency of NIV use varies across European countries. Higher severity of illness and more severe frailty were associated with a risk of NIV failure among critically ill older adults with COVID-19. Primary IMV was associated with better outcomes than primary NIV. Clinical Trial Registration NCT04321265 , registered 19 March 2020, https://clinicaltrials.gov

Post-imperialism, postcolonialism and beyond: towards a periodisation of cultural discourse about colonial legacies

Taking German history and culture as a starting point, this essay suggests a historical approach to reconceptualising different forms of literary engagement with colonial discourse, colonial legacies and (post-) colonial memory in the context of Comparative Postcolonial Studies. The deliberate blending of a historical, a conceptual and a political understanding of the ‘postcolonial’ in postcolonial scholarship raises problems of periodisation and historical terminology when, for example, anti-colonial discourse from the colonial period or colonialist discourse in Weimar Germany are labelled ‘postcolonial’. The colonial revisionism of Germany’s interwar period is more usefully classed as post-imperial, as are particular strands of retrospective engagement with colonial history and legacy in British, French and other European literatures and cultures after 1945. At the same time, some recent developments in Francophone, Anglophone and German literature, e.g. Afropolitan writing, move beyond defining features of postcolonial discourse and raise the question of the post-postcolonial