Strategyproof and Nonbossy Assignments

We consider the assignment of heterogeneous and indivisible objects to agents without using monetary transfers, where each agent may be assigned more than one object, and the valuation of the objects to an agent may depend on what other objects the agent is assigned. The set of strategyproof, nonbossy, and Pareto-optimal social choice functions is characterized as dictatorial sequential choice functions. Thus, the consequences of a Gibbard-Satterthwaite-type result can only be escaped in this context by using bossy social choice functions. It is also established that all strategyproof, strongly nonbossy and Pareto-optimal social choice functions are serial dictatorships, where strong nonbossiness is a stricter version of bossiness

Strategyproof Allocation of a Single Object

The problem of allocating a single indivisible object to one of several selfish agents is considered, where monetary payments are not allowed, and the object is not necessarily desirable to each agent. It is shown that ordinality and positive responsiveness together are necessary and sufficient conditions for strategyproofness, which implies that efficient social choice functions are not strategyproof. However, any Pareto-optimal, ordinal social choice function is strategyproof. A Gibbard-Satterthwaite-type impossibility result is established for nonbossy mechanisms. Thus, the best the planner can do without monetary transfers is to give the object to an agent who desires it, but whose valuation of the object may not be the highest among the agents, using a mechanism that is either dictatorial or bossy. It is also shown that all strategyproof, nonbossy, and Pareto-optimal social choice functions are serial dictatorships

The Mindset Classroom Blended Course

Northwest Louisiana houses a collective impact organization called Step Forward. It utilizes several networks to create change within the region. Stakeholders of the Middle Grade STEM Network were aware of the impact of growth mindset principles and practices on educators and students’ self-efficacy and needed to train regional formal and informal educators in growth mindset principles and practices. After ruling out available options due to cost, two network stakeholders and myself collaborated to create our own growth mindset training. An initial mini-pilot was conducted in the fall of 2017 followed by a needs assessment and learner analysis. Three primary goals and two secondary goals were identified. The three primary goals are for classroom and community educators to (a) deepen their understanding of growth mindset practices and principles, (b) understand the impact on learning of those practices and principles, and (c) create a stronger and deeper learning environment for the students they serve. The secondary goals for this course are to provide classroom and community educators with additional support during and in-between each in-person instructor-led workshop and to continue to engage and deepen educator understanding of growth mindset from workshop to workshop. A successful four-part, blended pilot course was implemented in the spring of 2018 meeting or exceeding most of our goals and objectives

Studies on nature of anisotropy of tensile properties and fibre orientation in cross-laid needle-punched nonwoven fabrics

An attempt has been made to study the fibre cross laying as well as fibre orientation angle in cross-laid needle-punched nonwoven fabric and its relationship with tensile properties of fabric. Nine fabric samples have been produced by using three types of fibres, namely 100 % polyester, 100 % jute and 50:50 jute-polyester blend with three different numbers of layers (6, 12 and 18). The tensile properties of different cross-laid structures have been measured not only in machine direction (MD) and cross direction (CD) but also at different angles including the angle of laying with respect to the width of the fabric followed by ANOVA analysis in order to assess the nature of anisotropy in terms of tensile properties. It is observed that the number of layers in the web influences the cross laying angle (LA) as well as tensile properties of the fabric. The maximum tenacity is obtained in case of CD and then the tenacity gradually reduces towards the MD. The ANOVA analysis of the data reveals that the cross-laid needle-punched nonwoven fabric possesses reasonable isotropy in respect of both fibre orientation and tenacity in all the fabrics

Fairness and group-strategyproofness clash in assignment problems

No group-strategyproof and ex-post Pareto optimal random matching mechanism treats equals equally. Every mechanism that arises out of the randomization over a set of non-bossy and strategyproof mechanisms is non-bossy. Random serial dictatorship, which arises out of a randomization over all deterministic serial dictatorships is non-bossy but not group-strategyproof

Unique Stability in Simple Coalition Formation Games

In this paper we study the existence and uniqueness of stable coalition structures, when the value of a coalition to a member depends solely on the other members of the coalition. We search for collections of admissible coalitions that induce uniquely stable coalition structures, that is, ensure that there is a unique stable coalition structure at every preference profile when only admissible coalitions may form. A collection of coalitions satisfies the single-lapping property if (a) no two coalitions have more than one member in common, and (b) in a cycle formed by coalitions with a non-empty intersection all the coalitions have the same member in common. We prove that a collection of coalitions induces a unique stable coalition structure if and only if it satisfies the single-lapping property. We also provide a graph representation of collections of coalitions that satisfy the single-lapping property. This alternative representation is used to explore implications of our characterization result for matching problems such as the marriage and roommate problems. We also discuss the implications for the existence of strategyproof rules of coalition formation.

Molecular structure of promoter-bound yeast TFIID.

Transcription preinitiation complex assembly on the promoters of protein encoding genes is nucleated in vivo by TFIID composed of the TATA-box Binding Protein (TBP) and 13 TBP-associate factors (Tafs) providing regulatory and chromatin binding functions. Here we present the cryo-electron microscopy structure of promoter-bound yeast TFIID at a resolution better than 5 Å, except for a flexible domain. We position the crystal structures of several subunits and, in combination with cross-linking studies, describe the quaternary organization of TFIID. The compact tri lobed architecture is stabilized by a topologically closed Taf5-Taf6 tetramer. We confirm the unique subunit stoichiometry prevailing in TFIID and uncover a hexameric arrangement of Tafs containing a histone fold domain in the Twin lobe

Replacing C6F5 groups with Cl and H atoms in frustrated Lewis pairs : H-2 additions and catalytic hydrogenations

2-(Dialkylamino) phenylboranes containing the BXZ group, where X, Z = C6F5, Cl, and H, were prepared in a few synthetic steps and demonstrated the cleavage of H-2 under mild conditions. Depending on the nature of the dialkylamino group, X, and Z, the stability of the produced zwitterionic H-2 adducts varies from isolated solids indefinitely stable in an inert atmosphere to those quickly equilibrating with the initial aminoborane and H-2. Using a combined experimental/computational approach on a series of isostructural aminoboranes (dialkylamino = 2,2,6,6-tetramethylpiperid-1-yl), it was demonstrated that the electro-negativity and the steric effect of the substituents generally follow the trend C6F5 similar to Cl >> H. This observation is useful for designing new FLPs for practical applications. As an example, we demonstrated the hydrogenation of alkynes to cis-alkenes under mild conditions that was catalyzed by a chloro-analogue of the C6F5-substituted aminoborane developed previously. The presence of a BHCl group in the amino-chloroboranes or in their H-2 adducts features facile redistribution of the H and Cl atoms and the formation of polychloro and polyhydrido species.Peer reviewe