A note on couette flow of nematic crystals according to the Ericksen–Leslie theory

In order to model the flow of nematic crystals, the theoretical framework according to Ericksen and Leslie is applied. The essentials of the theory are compiled and then specialized to Couette flow. The profiles for linear velocity and orientation angle will be computed and, in particular, we shall also study the rise in temperature due to viscous dissipation, which is frequently ignored by mechanicians. Analytical and numerical solutions for the fields are derived for different boundary conditions and will subsequently be discussed.TU Berlin, Open-Access-Mittel - 201

Nanoparticle-induced gene-silencing for the suppression of inflammation

A dysregulated immune system can cause many different diseases, like inflammatory bowel diseases. In most cases the dysregulation of the transcription factor NF-κB as central regulator is involved. The treatment options are limited and coupled with severe side effects. In recent years, novel treatments like the application of nanoparticles (NPs) as carrier systems for the targeted delivery of drugs have emerged. The mechanism of RNA interference is an advantageous new therapeutic platform. The biological activity of a novel formulation of calcium phosphate NPs with incorporated p65 siRNA is assessed concerning the ability to silence NF-κB p65 expression and ameliorate inflammatory processes. The NPs are internalized in key cellular players of inflammation. The specific decoration of the NPs even increased the uptake in some cell types. The internalization process was mostly energy-dependent, and the cargo of the NPs was localized in the cytoplasm after uptake. Moreover, the p65 siRNA NPs were efficient in downregulating p65 in target cells with variably strong impact. Investigations concerning the therapeutic efficiency in a murine colitis model revealed a distinct amelioration of the local inflammation after intravenous application of the NPs with p65 siRNA. A distinct impact of the NPs on the inflammatory signaling cascade in the colon was shown. The biodistribution of the NPs was clearly influenced by the colonic inflammation with increased localization in the adjacent lymphoid organs. NPs carrying non-functional, scrambled siRNA also showed distinct impact on the colonic inflammation, while no notable off-target effects of the NPs were found in the colon of healthy mice. Here a versatile novel NP-based system for the suppression of NF-κB-mediated pro-inflammatory reactions and therefore the amelioration of colonic inflammation is demonstrated as a promising approach as a treatment of a plethora of different acute and chronic diseases in the future

Jet Quenching and Holographic Thermalization

We employ the AdS/CFT correspondence to investigate the thermalization of the strongly-coupled plasma and the jet quenching of a hard probe traversing such a thermalizing medium.Comment: 3 pages, 2 figures, The proceeding of Eleventh Conference on the Intersections of Particle and Nuclear Physics --- CIPANP 2012, May 28, 2012 - June 3, 2012, St. Petersburg, FL, US

The communication complexity of private value single item auctions

In this paper we present a new auction, the bisection auction, that can be used for the sale of a single indivisible object. We discuss the issue concerning the information revelation requirement of this auction and the associated amount of data that needs to be transmitted. We show that in the truthtelling equilibrium the bisection auction is economical in its demand for information on the valuations of the players. It requires the players to transmit less information bits to the auctioneer than the Vickrey and English auctions. In particular, we prove that for integer valuations uniformly distributed on the interval [0,L) the bisection auction of n players requires in expectation transmission of at most 2n + log L information bits by the players. Compared with the corresponding number in the Vickrey auction which is n log L, and in the English auction which is on average at least (1/3) nL, the bisection auction turns out to be the best performer.mathematical economics;

Making Women Development Fund More Care-Responsive

The Women Development Fund (WDF) was established by the Government of Tanzania in 1992, with the objective to support the economic empowerment of women, and especially rural women. This note discusses the main findings of research in relation to the care-sensitivity of the WDF. The research was undertaken by the Institute of Development Studies and BRAC Research and Evaluation Unit, and implemented in Korogwe and Lushoto districts. The research hypothesis argues that taking unpaid care work into account in women’s economic empowerment (WEE) policies and programmes has the potential to significantly strengthen the empowering outcomes of women’s participation in paid work. This would therefore turn a ‘double burden’ into a ‘double boon’ – i.e. paid work that empowers women and provides more support for their unpaid care work responsibilities. The note provides a set of recommendations to the WDF on how to mainstream unpaid care work into women’s economic empowerment (WEE) programming, which include: providing a convenient platform for engaging with issues related to the reduction and redistribution of unpaid care work; exchanging lessons learned and best practices, and establishing synergies with other like-minded programmes active in Tanzania; lobbying for increasing the government’s investment in public services and better infrastructure; and expanding women’s access to markets and finance.Department for International Development (DFID)William and Flora Hewlett FoundationInternational Development Research Centre (IDRC

Oxfam’s Food Security for Tanzania Farmers Programme: Guidelines for Achieving the Double Boon

The Oxfam Food Security for Tanzania Farmers programme (2012–15) aimed to increase food production and income, and improve the quality of life and food security for smallholder farmers, particularly women, in Tanzania. In Lushoto and Korogwe districts, it focused in particular on the domestic vegetable value chain (VVC), where rates of women’s participation are lower as compared to other agricultural crop production. In 2015–17, the project ‘Balancing unpaid care work and paid work: successes, challenges and lessons for women’s economic empowerment programmes and policies’ investigated how women’s economic empowerment (WEE) policies and programmes take unpaid care work into account, in order to enable women’s economic empowerment to be optimised. How does access to decent work play a key role in enabling women to achieve a ‘double boon’ through their participation in economically empowering work? This note discusses the main findings of the research in relation to the care-sensitivity of the Oxfam programme. It offers recommendations to Oxfam on how unpaid care work can be mainstreamed into its WEE programming, particularly by: helping to set up and maintain women’s groups to enable collective action; sharing its knowledge and experience to support other organisations in this kind of work; helping women lobby for increased access to markets; enabling women to campaign for better public services and infrastructure; helping families plan and redistribute the division of care tasks of household members; and encouraging families to send their children to school, discouraging the transfer of onerous care tasks that disrupt schooling.Department for International Development (DFID)William and Flora Hewlett FoundationInternational Development Research Centre (IDRC

Inefficiency of equilibria in query auctions with continuous valuations

Query auctions are iterative auctions in which bidders have to select in each round an action from a finite set. We show that, when bidders have continuous valuations, any ex post equilibrium in an ex post individually rational query auction can only be ex post efficient when the running time of the auction is infinite for almost all realizations of valuations of thebidders. Thus, when valuations are drawn from a continuous probability distribution, efficiency can only be bought at the expense of a running time that is infinite with probability one. For two bidders we even show this to be true when we only require efficiency with probability one.mathematical economics;

Fraction auctions: the tradeoff between effciency and running time

This paper studies the sales of a single indivisible object where bidders have continuous valuations. In Grigorieva et al. [13] it was shown that, in this setting, query auctions necessarily allocate inefficiently in equilibrium. In this paper we propose a new sequential auction, called the c-fraction auction. We show c-fraction auctions guarantee approximate efficiency at any desired level of accuracy, independent of the number of bidders. We discuss the running time and the efficiency in the ex-post equilibrium of the auction. We show that by changing the parameter c of the auction we can trade off efficiency against running time.operations research and management science;

On The Fastest Vickrey Algorithm

We investigate the algorithmic performance of Vickrey-Clarke-Groves mechanisms in the single item case. We provide a formal definition of a Vickrey algorithm for this framework, and give a number of examples of Vickrey algorithms. We consider three performance criteria, one corresponding to a Pareto criterion, one corresponding to worst case analysis, and a third criterion related to first-order stochastic dominance. We show that Pareto optimal Vickrey algorithms do not exist and that worst case analysis is of no use in discriminating between Vickrey algorithms. For the case of two bidders, we show the bisection auction to be optimal according to the third criterion. The bisection auction istherefore optimal in a very strong sense.operations research and management science;

Inefficiency of equilibria in query auctions with continuous valuations

We show that, when bidders have continuous valuations, any ex post equilibrium in an ex post individually rational query auction can only be ex post efficient when the running timeof the auction is infinite for almost all realizations of valuations of the bidders. We also show that this result applies to the general class of bisection auctions. In contrast we show that, when we allow for inefficient allocations with arbitrarily small probability, there is a query auction (to be more specific, a bisection auction) that attains this level of approximate efficiency in equilibrium, while additionally the running time of the auction in equilibrium is finite for all realizations of valuations.mathematical economics;