Reduced Toxicity Conditioning with Busulfan, Fludarabine, Alemtuzumab and Allogeneic Stem Cell Transplantation From HLA-Matched Sibling Donors in Children with High Risk Sickle Cell Disease Results in Long Term Donor Chimerism and Low Incidence of aGVHD

Purpose It is still equivocal whether oxygen uptake recovery kinetics are limited by oxygen delivery and can be improved by supplementary oxygen. The present study aimed to investigate whether measurements of muscle and pulmonary oxygen uptake kinetics can be used to assess oxygen delivery limitations in healthy subjects. Methods Sixteen healthy young adults performed three sub-maximal exercise tests (6 min at 40% Wmax) under hypoxic (14%O2), normoxic (21%O2) and hyperoxic (35%O2) conditions on separate days in randomized order. Both Pulmonary VO2 and near infra red spectroscopy (NIRS) based Tissue Saturation Index (TSI) offset kinetics were calculated using mono-exponential curve fitting models. Results Time constant τ of VO2 offset kinetics under hypoxic (44.9 ± 7.3s) conditions were significantly larger than τ of the offset kinetics under normoxia (37.9 ± 8.2s, p = 0.02) and hyperoxia (37±6s, p = 0.04). TSI mean response time (MRT) of the offset kinetics under hypoxic conditions (25.5 ± 13s) was significantly slower than under normoxic (15 ± 7.7, p = 0.007) and hyperoxic (13 ± 7.3, p = 0.008) conditions. Conclusion The present study shows that there was no improvement in the oxygen uptake and muscle oxygenation recovery kinetics in healthy subjects under hyperoxic conditions. Slower TSI and VO2 recovery kinetics under hypoxic conditions indicate that both NIRS and spiro-ergometry are appropriate non-invasive measurement tools to assess the physiological response of a healthy individual to hypoxic exercise

Advancing Qualitative Entrepreneurship Research: Leveraging Methodological Plurality for Achieving Scholarly Impact

This editorial aims to advance the use of qualitative research methods when studying entrepreneurship. First, it outlines four characteristics of the domain of entrepreneurship that qualitative research is uniquely placed to address. In studying these characteristics, we urge researchers to leverage the plurality of different qualitative approaches, including less conventional methods. Second, to help researchers develop high-level theoretical contributions, we point to multiple possible contributions, and highlight how such contributions can be developed through qualitative methods. Thus, we aim to broaden the types of contributions and forms that qualitative entrepreneurship research takes, in ways that move beyond prototypical inductive theory-building

Advancing Qualitative Entrepreneurship Research: Leveraging Methodological Plurality for Achieving Scholarly Impact

This editorial aims to advance the use of qualitative research methods when studying entrepreneurship. First, it outlines four characteristics of the domain of entrepreneurship that qualitative research is uniquely placed to address. In studying these characteristics, we urge researchers to leverage the plurality of different qualitative approaches, including less conventional methods. Second, to help researchers develop high-level theoretical contributions, we point to multiple possible contributions, and highlight how such contributions can be developed through qualitative methods. Thus, we aim to broaden the types of contributions and forms that qualitative entrepreneurship research takes, in ways that move beyond prototypical inductive theory-building

Advancing Qualitative Entrepreneurship Research: Leveraging Methodological Plurality for Achieving Scholarly Impact

This editorial aims to advance the use of qualitative research methods when studying entrepreneurship. First, it outlines four characteristics of the domain of entrepreneurship that qualitative research is uniquely placed to address. In studying these characteristics, we urge researchers to leverage the plurality of different qualitative approaches, including less conventional methods. Second, to help researchers develop high-level theoretical contributions, we point to multiple possible contributions, and highlight how such contributions can be developed through qualitative methods. Thus, we aim to broaden the types of contributions and forms that qualitative entrepreneurship research takes, in ways that move beyond prototypical inductive theory-building

Dynamic vehicle routing with time windows in theory and practice

The vehicle routing problem is a classical combinatorial optimization problem. This work is about a variant of the vehicle routing problem with dynamically changing orders and time windows. In real-world applications often the demands change during operation time. New orders occur and others are canceled. In this case new schedules need to be generated on-the-fly. Online optimization algorithms for dynamical vehicle routing address this problem but so far they do not consider time windows. Moreover, to match the scenarios found in real-world problems adaptations of benchmarks are required. In this paper, a practical problem is modeled based on the procedure of daily routing of a delivery company. New orders by customers are introduced dynamically during the working day and need to be integrated into the schedule. A multiple ant colony algorithm combined with powerful local search procedures is proposed to solve the dynamic vehicle routing problem with time windows. The performance is tested on a new benchmark based on simulations of a working day. The problems are taken from Solomon’s benchmarks but a certain percentage of the orders are only revealed to the algorithm during operation time. Different versions of the MACS algorithm are tested and a high performing variant is identified. Finally, the algorithm is tested in situ: In a field study, the algorithm schedules a fleet of cars for a surveillance company. We compare the performance of the algorithm to that of the procedure used by the company and we summarize insights gained from the implementation of the real-world study. The results show that the multiple ant colony algorithm can get a much better solution on the academic benchmark problem and also can be integrated in a real-world environment

Minimal model for aeolian sand dunes

We present a minimal model for the formation and migration of aeolian sand dunes. It combines a perturbative description of the turbulent wind velocity field above the dune with a continuum saltation model that allows for saturation transients in the sand flux. The latter are shown to provide the characteristic length scale. The model can explain the origin of important features of dunes, such as the formation of a slip face, the broken scale invariance, and the existence of a minimum dune size. It also predicts the longitudinal shape and aspect ratio of dunes and heaps, their migration velocity and shape relaxation dynamics. Although the minimal model employs non-local expressions for the wind shear stress as well as for the sand flux, it is simple enough to serve as a very efficient tool for analytical and numerical investigations and to open up the way to simulations of large scale desert topographies.Comment: 19 pages, 22 figure

Dynamic vehicle routing with time windows in theory and practice

The vehicle routing problem is a classical combinatorial optimization problem. This work is about a variant of the vehicle routing problem with dynamically changing orders and time windows. In real-world applications often the demands change during operation time. New orders occur and others are canceled. In this case new schedules need to be generated on-the-fly. Online optimization algorithms for dynamical vehicle routing address this problem but so far they do not consider time windows. Moreover, to match the scenarios found in real-world problems adaptations of benchmarks are required. In this paper, a practical problem is modeled based on the procedure of daily routing of a delivery company. New orders by customers are introduced dynamically during the working day and need to be integrated into the schedule. A multiple ant colony algorithm combined with powerful local search procedures is proposed to solve the dynamic vehicle routing problem with time windows. The performance is tested on a new benchmark based on simulations of a working day. The problems are taken from Solomon's benchmarks but a certain percentage of the orders are only revealed to the algorithm during operation time. Different versions of the MACS algorithm are tested and a high performing variant is identified. Finally, the algorithm is tested in situ: In a field study, the algorithm schedules a fleet of cars for a surveillance company. We compare the performance of the algorithm to that of the procedure used by the company and we summarize insights gained from the implementation of the real-world study. The results show that the multiple ant colony algorithm can get a much better solution on the academic benchmark problem and also can be integrated in a real-world environment.Algorithms and the Foundations of Software technolog

Optimal Collision Security in Double Block Length Hashing with Single Length Key

The idea of double block length hashing is to construct a compression function on 2n bits using a block cipher with an n-bit block size. All optimally secure double length hash functions known in the literature employ a cipher with a key space of double block size, 2n-bit. On the other hand, no optimally secure compression functions built from a cipher with an n-bit key space are known. Our work deals with this problem. Firstly, we prove that for a wide class of compression functions with two calls to its underlying n-bit keyed block cipher collisions can be found in about 2n/2 queries. This attack applies, among others, to functions where the output is derived from the block cipher outputs in a linear way. This observation demonstrates that all security results of designs using a cipher with 2n-bit key space crucially rely on the presence of these extra n key bits. The main contribution of this work is a proof that this issue can be resolved by allowing the compression function to make one extra call to the cipher. We propose a family of compression functions making three block cipher calls that asymptotically achieves optimal collision resistance up to 2n(1-ε) queries and preimage resistance up to 23n(1-ε)/2 queries, for any ε > 0. To our knowledge, this is the first optimally collision secure double block length construction using a block cipher with single length key space. © International Association for Cryptologic Research 2012.status: publishe

Comedy in Unfunny Times: News Parody and Carnival after 9/11

Comedy has a special role in helping societies manage crisis moments, and the U.S. media paid considerable attention to the proper role of comedy in public culture after the 9/11 tragedies. As has been well documented, many popular U.S. comic voices were paralyzed in trying to respond to 9/11 or disciplined by audiences when they did. Starting with these obstacles in mind, this essay analyzes early comic responses to 9/11, and particularly those of the print and online news parody The Onion, as an example of how “fake” news discourse could surmount the rhetorical chill that fell over public culture after the tragedies. By exposing the news as “mere” production and by setting an agenda for learning about Islamic culture and Middle East politics, The Onion avoided violating decorum and invited citizen participation. This kind of meta-discourse was crucial after 9/11, when shifting rules for decorum created controversy and as official voices in government and media honed frames and narratives for talking about the attacks