Parameterized Rural Postman Problem

The Directed Rural Postman Problem (DRPP) can be formulated as follows: given a strongly connected directed multigraph $D=(V,A)$ with nonnegative integral weights on the arcs, a subset $R$ of $A$ and a nonnegative integer $\ell$, decide whether $D$ has a closed directed walk containing every arc of $R$ and of total weight at most $\ell$. Let $k$ be the number of weakly connected components in the the subgraph of $D$ induced by $R$. Sorge et al. (2012) ask whether the DRPP is fixed-parameter tractable (FPT) when parameterized by $k$, i.e., whether there is an algorithm of running time $O^*(f(k))$ where $f$ is a function of $k$ only and the $O^*$ notation suppresses polynomial factors. Sorge et al. (2012) note that this question is of significant practical relevance and has been open for more than thirty years. Using an algebraic approach, we prove that DRPP has a randomized algorithm of running time $O^*(2^k)$ when $\ell$ is bounded by a polynomial in the number of vertices in $D$. We also show that the same result holds for the undirected version of DRPP, where $D$ is a connected undirected multigraph

Parameterized Two-Player Nash Equilibrium

We study the computation of Nash equilibria in a two-player normal form game from the perspective of parameterized complexity. Recent results proved hardness for a number of variants, when parameterized by the support size. We complement those results, by identifying three cases in which the problem becomes fixed-parameter tractable. These cases occur in the previously studied settings of sparse games and unbalanced games as well as in the newly considered case of locally bounded treewidth games that generalizes both these two cases

[Special Issue on Hmong Newcomers to Saint Paul Public Schools] Are We There Yet? Examining the Principals Role in the Integration of Hmong Refugee Children into Elementary Schools

This paper examines the efforts of four elementary principals to create a welcoming and integrated culture for newly arrived Wat Tham Krabok refugee Hmong children. It reveals the accommodations and challenges made by the schools. It demonstrates that the effectiveness of a specialized program for newcomer refugee children necessitates careful planning and the involvement of staff members and school leaders

The Value of Different Levels of Streptomycin-Sulfaquinoxaline and Chlortetracycline (Aureomycin) for Growing Pigs

Results of previous experiments at this station and elsewhere indicated that several of the antibiotics caused increases in daily gain of growing pigs. High level (50-100 grams per ton) antibiotic feeding has resulted in an increase in feed efficiency in trials conducted here the past two years. During the past year two experiments were conducted to compare feeding different levels of a mixture of streptomycin-sulfaquinoxaline and chlortetracycline. The first experiment was conducted during the winter of 1956-57and the second experiment during the summer of 1957

The Effect of Vitamin D in Rations for Growing Pigs Fed in the Absence of Direct Sunlight

Previous to this experiment two trials were conducted here that did not indicate a need for supplemental vitamin D for growing pigs fed in the absence of direct sunlight. In these previous trials a complete mixed ration containing recommended amounts of calcium and phosphorus was fed. The experiment reported here was conducted to see if supplemental vitamin D was required for growing pigs in the absence of sunlight when a mineral supplement was fed free-choice as cell as when a complete mixed ration was fed

Buckling Loads for Partially Embedded Piles

Piles are common structural elements used to transmit loads through weak or compressible surface soils to lower, more suitable soil strata. They are relatively small diameter shafts that are forced into the ground. Typical examples of pile utilization can be found at nearly any site where a major structure is being constructed. Many waterfront structures are built on partially embedded piles. In this case, the pile transfers the load of the structure to the lower soil strata and also serves as a column for the portion of the structure above the mud line. Many bridges and buildings are also supported by partially embedded piles. This is especially true for structures in permafrost areas. The load bearing capacity of totally embedded and partially embedded piles can usually be determined using readily accepted design procedures. The load bearing capacity of totally embedded and partially embedded piles can usually be determined using readily accepted design procedures. However, the design of partially embedded piles is further complicated by the fact that the column portion of the pile extends below the surface to some point where it can be considered as fixed. It follows, then, that before the design process can proceed, this point of fixity must be defined

Vitamins, Trace Minerals and Feed Additives

Although natural feedstuffs supply varying amounts of most of the vitamins and trace minerals, practical diets for swine are generally supplemented with certain of these nutrients. This article will discuss those vitamins and trace minerals that need more attention in swine feeding and feed additives that are used for growth promotion

Winter Dry-Lot Supplements for Growing Pigs

Research conducted at South Dakota in 1955-56 has shown that 10 to 19 per cent of ground alfalfa hay in a protein supplement will decrease the consumption of the supplement (S. Dak. Farm and Home Research, Feb. 1957). This resulted in a lowering of the feed cost per unit of pig gain. The objectives of this experiment were to compare three levels (10, 20 and 30 per cent) of ground alfalfa hay in a protein supplement and to compare these supplements fed free-choice to a complete mixed ration