On the reconstruction of linear codes

For a linear code over GF (q) we consider two kinds of `subcodes' called residuals and punctures. When does the collection of residuals or punctures determine the isomorphism class of the code? We call such a code residually or puncture reconstructible. We investigate these notions of reconstruction and show that, for instance, selfdual binary codes are puncture and residually reconstructible. A result akin to the edge reconstruction of graphs with sufficiently many edges shows that a code whose dimension is small in relation to its length is puncture reconstructible

Efficient reconstruction of partitions

AbstractWe consider the problem of reconstructing a partition x of the integer n from the set of its t-subpartitions. These are the partitions of the integer n-t obtained by deleting a total of t from the parts of x in all possible ways. It was shown (in a forthcoming paper) that all partitions of n can be reconstructed from t-subpartitions if n is sufficiently large in relation to t. In this paper we deal with efficient reconstruction, in the following sense: if all partitions of n are t--reconstructible, what is the minimum number N=N-(n,t) such that every partition of n can be identified from any N+1 distinct subpartitions? We determine the function N-(n,t) and describe the corresponding algorithm for reconstruction. Superpartitions may be defined in a similar fashion and we determine also the maximum number N+(n,t) of t-superpartitions common to two distinct partitions of n

Evaluation of the Spherical Flange Concept for a Rocket Engine

Due to the inherent tolerance variability of hardware, flange misalignments occur during installation of mating components for a liquid propellant rocket engine. Flange misalignments include axial, lateral, and angular offsets. If these misalignments are high, they can impart significant loads into the two mating components. These significant loads can then be a driver in the design of the propellant ducts. Such was the case for the Rocketdyne RS-83 engine design for the Space Launch Initiative Program. To address this flange misalignment issue, Marshall Space Flight Center joined with Rocketdyne to develop and test a spherical flange system that allows for misalignment, yet reduces loads imparted, and at the same time provides sufficient sealing against leakage. The flange design was tested to evaluate and compare performance parameters such as misalignment and leakage. The environmental conditions ranged from -100 to 400 degrees Fahrenheit (F) with 1000 to 4000 pounds per square inch gage (psig) pressure. The desirable design features will be extracted and synthesized into a new flange design concept. This paper will address the spherical flange design and the test results

catena-Poly[[[diaqua­(nitrato-κ2 O,O′)(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)ytterbium(III)]-μ-cyanido-κ2 N:C-[dicyanido­platinum(II)]-μ-cyanido-κ2 C:N] acetonitrile monosolvate]

The title compound, {[PtYb(CN)4(NO3)(C15H11N3)(H2O)2]·CH3CN}n, was isolated from solution as a one-dimensional coordination polymer. The Yb3+ site has ninefold coordination with a distorted tricapped trigonal–prismatic geometry, while the PtII ion is coordinated by four cyanide groups in an almost regular square-planar geometry. cis-Bridging by the tetra­cyanidoplatinate(II) anions links the Yb3+ cations, forming chains. Additionally, each Yb3+ is coordinated by two water mol­ecules, one bidentate nitrate anion, and one tridentate 2,2′:6′,2′′-terpyridine mol­ecule. O—H⋯N hydrogen-bonding inter­actions are found between adjacent chains and help to consolidate the crystal packing. In addition, π–π stacking inter­actions exist between the terpyridine ligand and the two corresponding terpyridine ligands along the adjacent chain (average inter­planar distance = 3.667 Å). Moderate Pt⋯Pt inter­actions [3.5033 (4) Å] are observed in the structure

Low Cost Quadruped: MUTT

The field of educational and research robotics is alight with development platforms that fall short of being interesting and novel. Our goal was to create a quadruped for use as an entry level research project for students and educators. Reducing cost through the use of commercially available parts combined with rapid-prototyping, we built a platform that can be used to teach and learn legged locomotion for less than $600 (half the price of a Turtlebot 2 from OSRF). Our robot was able to walk in basic form using limited actuation; this was limited by the components we chose - specifically the motor controllers for part of the actuation. We expect that using components better suited to the task could accomplish what we set out to achieve

catena-Poly[[[diaqua­(nitrato-κ2 O,O′)(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)neodymium(III)]-μ-cyanido-κ2 N:C-[dicyanidoplatinum(II)]-μ-cyanido-κ2 C:N] acetonitrile solvate 2,2′:6′,2′′-terpyridine hemisolvate]

The title compound, {[NdPt(CN)4(NO3)(C15H11N3)(H2O)2]·CH3CN·0.5C15H11N3}n, was isolated from solution as a one-dimensional coordination polymer. The Nd3+ site in the structure has a ninefold coordination with a distorted tricapped trigonal-prismatic geometry, while the PtII ion is coordinated by four cyanide groups in an almost regular square-planar geometry. Cis-bridging by the tetracyanidoplatinate anions links the Nd3+ cations, forming the one-dimensional chains. Additionally, each Nd3+ contains coordin­ation by two water mol­ecules, one tridentate 2,2′:6′,2′′-terpyridine mol­ecule, and one bidentate nitrate anion. 2,2′:6′,2′′-Terpyridine and acetonitrile solvent mol­ecules are incorporated between the chains, the former form π-stacking inter­actions (average inter­planar distance 3.33 Å) with terpyridine mol­ecules located in the chains. Relatively long Pt⋯Pt inter­actions [3.847 (1) Å] are observed in the structure. O—H⋯N and O—H⋯O hydrogen bonding interactions between the consituents consolidates the crystal packing

How does the phrasing of house edge information affect gamblers’ perceptions and level of understanding? A registered report

The provision of information to consumers is a common input to tackling various public health issues. By comparison to the information given on food and alcohol products, information on gambling products is either not given at all, or shown in low-prominence locations in a suboptimal format, e.g. the ‘return-to-player’ format, ‘this game has an average percentage payout of 90%’. Some previous research suggests that it would be advantageous to communicate this information via the ‘house edge’ format instead: the average loss from a given gambling product, e.g. ‘this game keeps 10% of all money bet on average’. However, previous empirical work on the house edge format only uses this specific phrasing, and there may be better ways of communicating house edge information. The present work experimentally tested this original phrasing of the house edge against an alternative phrasing that has also been proposed, ‘on average this game is programmed to cost you 10% of your stake on each bet’, while both phrasings were also compared against equivalent return-to-player information (N = 3333 UK-based online gamblers). The two dependent measures were gamblers’ perceived chances of winning and a measure of participants’ correct understanding. Preregistered Stage 1 protocol: https://osf.io/5npy9 (date of in-principle acceptance: 28/11/2022). The alternative house edge phrasing resulted in the lowest perceived chances of winning, but the original phrasing had the highest rate of correct understanding. Compared to return-to-player information, the original phrasing had both lower perceived chances of winning and higher rates of correct understanding, while the alternative phrasing had only lower perceived chances of winning. These results replicated prior work on the advantages of the original house edge phrasing over return-to-player information, while showing that the alternative house edge phrasing has advantageous properties for gamblers’ perceived chances of winning only. The optimal communication of risk information can act as an input to a public health approach to reducing gambling-related harm

Recombinant antigens based on toxins A and B of Clostridium difficile that evoke a potent toxin-neutralising immune response

AbstractInfection with the bacterium Clostridium difficile causes symptoms ranging from mild to severe diarrhoea with life-threatening complications and remains a significant burden to healthcare systems throughout the developed world. Two potent cytotoxins, TcdA and TcdB are the prime mediators of the syndrome and rapid neutralisation of these would afford significant benefits in disease management. In the present study, a broad range of non-toxic, recombinant fragments derived from TcdA and TcdB were designed for soluble expression in E. coli and assessed for their capacity to generate a potent toxin-neutralising immune response as assessed by cell-based assays. Significant differences between the efficacies of isolated TcdA and TcdB regions with respect to inducing a neutralising immune response were observed. While the C-terminal repeat regions played the principal role in generating neutralising antibodies to TcdA, in the case of TcdB, the central region domains dominated the neutralising immune response. For both TcdA and TcdB, fragments which comprised domains from both the central and C-terminal repeat region of the toxins were found to induce the most potent neutralising immune responses. Generated antibodies neutralised toxins produced by a range of C. difficile isolates including ribotype 027 and 078 strains. Passive immunisation of hamsters with a combination of antibodies to TcdA and TcdB fragments afforded complete protection from severe CDI induced by a challenge of bacterial spores. The results of the study are discussed with respect to the development of a cost effective immunotherapeutic approach for the management of C. difficile infection