Classification of Minimal Separating Sets in Low Genus Surfaces

Consider a surface $S$ and let $M\subset S$. If $S\setminus M$ is not connected, then we say $M$ \emph{separates} $S$, and we refer to $M$ as a \emph{separating set} of $S$. If $M$ separates $S$, and no proper subset of $M$ separates $S$, then we say $M$ is a \emph{minimal separating set} of $S$. In this paper we use methods of computational combinatorial topology to classify the minimal separating sets of the orientable surfaces of genus $g=2$ and $g=3$. The classification for genus 0 and 1 was done in earlier work, using methods of algebraic topology.Comment: 24 pages, 5 figures, 2 tables (11 pages

MARKETING MECHANISMS IN GM GRAINS AND OILSEEDS

A number of challenges exist for genetically modified (GM) crop development at the production level. Contract strategies can resolve these challenges. Contracts can be designed to induce legal adoption of GM wheat by varying technology fees, violation detection, and penalties. The primary objective of this research is to analyze contracting strategies to determine terms to minimize technology agreement violation and to induce legal adoption of GM wheat. A simulation model of a crop budget for Hard Red Spring wheat was developed. Results illustrate that contracts can be designed to induce desired behavior. Technology fee, probability of detection, and the level of non-GM premium were the most notable factors influencing adoption decisions.Producer Decisions, Risk, Genetically Modified, Contract Terms, Wheat, Crop Production/Industries,

INCENTIVE CONTRACTS TO MEET FUNCTIONAL CHARACTERISTICS IN WHEAT PURCHASING

Consistency of functional characteristics in hard red spring (HRS) wheat is a concern confronting sellers and buyers. This research analyzes contract incentives for importers with respect to cost and potential risk of acceptance. A principal-agent framework is utilized to examine contract incentives. In the principal-agent contract, the principal offers the contract, the agent rejects or accepts the contract, and then decides how much effort to apply. All this is subject to risk for the agent and moral hazard for the principal. An example is presented, for which equilibrium contract terms are a base price of 454 cents per bushel for low quality wheat and a premium of 36 cents per bushel if high quality is achieved. The premium for high quality is unchanged as the agent's outside option increases, but increases as the probability of conformance with high effort declines or as the agent's cost of high effort increases. Small changes in several of the parameter values (agent's outside option, agent's cost of high/low effort, principal value for high/low effort, and principal's outside options if the contract was not extended or if the agent rejects the contract) result in the principal not offering a contract.Incentive Contact, Functional Characteristic, Wheat, Principal-Agent, Crop Production/Industries,

NASA Headquarters Space Operations Center: Providing Situational Awareness for Spaceflight Contingency Response

This paper discusses the NASA Headquarters mishap response process for the Space Shuttle and International Space Station programs, and how the process has evolved based on lessons learned from the Space Shuttle Challenger and Columbia accidents. It also describes the NASA Headquarters Space Operations Center (SOC) and its special role in facilitating senior management's overall situational awareness of critical spaceflight operations, before, during, and after a mishap, to ensure a timely and effective contingency response

Spectral properties of random graphs with fixed equitable partition

We define a graph to be $S$-regular if it contains an equitable partition given by a matrix $S$. These graphs are generalizations of both regular and bipartite, biregular graphs. An $S$-regular matrix is defined then as a matrix on an $S$-regular graph consistent with the graph's equitable partition. In this paper we derive the limiting spectral density for large, random $S$-regular matrices as well as limiting functions of certain statistics for their eigenvector coordinates as a function of eigenvalue. These limiting functions are defined in terms of spectral measures on $S$-regular trees. In general, these spectral measures do not have a closed-form expression; however, we provide a defining system of polynomials for them. Finally, we explore eigenvalue bounds of $S$-regular graph, proving an expander mixing lemma, Alon-Bopana bound, and other eigenvalue inequalities in terms of the eigenvalues of the matrix $S$.Comment: 24 pages, 3 figure

Supportability for Beyond Low Earth Orbit Missions

Exploration beyond Low Earth Orbit (LEO) presents many unique challenges that will require changes from current Supportability approaches. Currently, the International Space Station (ISS) is supported and maintained through a series of preplanned resupply flights, on which spare parts, including some large, heavy Orbital Replacement Units (ORUs), are delivered to the ISS. The Space Shuttle system provided for a robust capability to return failed components to Earth for detailed examination and potential repair. Additionally, as components fail and spares are not already on-orbit, there is flexibility in the transportation system to deliver those required replacement parts to ISS on a near term basis. A similar concept of operation will not be feasible for beyond LEO exploration. The mass and volume constraints of the transportation system and long envisioned mission durations could make it difficult to manifest necessary spares. The supply of on-demand spare parts for missions beyond LEO will be very limited or even non-existent. In addition, the remote nature of the mission, the design of the spacecraft, and the limitations on crew capabilities will all make it more difficult to maintain the spacecraft. Alternate concepts of operation must be explored in which required spare parts, materials, and tools are made available to make repairs; the locations of the failures are accessible; and the information needed to conduct repairs is available to the crew. In this paper, ISS heritage information is presented along with a summary of the challenges of beyond LEO missions. A number of Supportability issues are discussed in relation to human exploration beyond LEO. In addition, the impacts of various Supportability strategies will be discussed. Any measure that can be incorporated to reduce risk and improve mission success should be evaluated to understand the advantages and disadvantages of implementing those measures. Finally, an effort to model and evaluate Supportability for beyond LEO missions will be described

Basal cell carcinoma treated successfully with combined CO2 laser and photodynamic therapy in a renal transplant patient: a case report

Renal transplant recipients are at significantly greater risk of developing skin malignancies due to combination immunosuppressive therapy. A significant number of patients present with lesions needing excision at multiple outpatient follow-up visits. For basal cell carcinoma, we have recently described how combining CO2 laser with Photodynamic therapy greatly increases the efficacy of long-term tumour clearance compared with each modality alone. We present a case of a 66-year-old renal transplant therapy patient who repeatedly presents with new skin malignancies, in whom we treated successfully with Laser-Photodynamic therapy in a see-and-treat setting. This therapy offers patients the possibility of better cosmetic and functional results whilst obviating the need for repeated surgery. Other pre-cancerous lesions such as solar keratoses are prevalent in this patient group and respond extremely well to Photodynamic therapy monotherapy. We propose a regular clinic for renal transplant patients in a laser facility equipped with CO2 laser and Photodynamic therapy, histopathology and punch-biopsy materials. This strategy allows simple and effective treatment of multiple lesions simultaneously, avoidance of numerous operations, avoidance of non-essential outpatient appointments that result in booking furthers visits for treatment, whilst facilitating diagnostic biopsies of potentially malignant lesions. We outline a care pathway for a see-and-treat clinic that implements this novel treatment modality improving the care of this unique patient population

Exact synthesis of multiqubit Clifford-cyclotomic circuits

Let $n\geq 8$ be an integer divisible by 4. The Clifford-cyclotomic gate set $\mathcal{G}_n$ is the universal gate set obtained by extending the Clifford gates with the $z$-rotation $T_n = \mathrm{diag}(1,\zeta_n)$, where $\zeta_n$ is a primitive $n$-th root of unity. In this note, we show that, when $n$ is a power of 2, a multiqubit unitary matrix $U$ can be exactly represented by a circuit over $\mathcal{G}_n$ if and only if the entries of $U$ belong to the ring $\mathbb{Z}[1/2,\zeta_n]$. We moreover show that $\log(n)-2$ ancillas are always sufficient to construct a circuit for $U$. Our results generalize prior work to an infinite family of gate sets and show that the limitations that apply to single-qubit unitaries, for which the correspondence between Clifford-cyclotomic operators and matrices over $\mathbb{Z}[1/2,\zeta_n]$ fails for all but finitely many values of $n$, can be overcome through the use of ancillas

\u3cem\u3eCatena\u3c/em\u3e-Poly[[Bis(α-Thenoyltrifluoroacetonato)Copper(II)]-μ-1,4-Di-4-Pyridyl-2,3-Diazabuta-1,3-Diene]

In the one-dimensional title polymer, [Cu(C8H4F3O2S)2(C12H10N4)]n or [Cu(L)2(tta)2] [tta is -thenoyltrifluoroacetonato and L is 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene], Cu2+ lies on a center of inversion. It is axially coordinated by two pyridyl N atoms from two different L ligands and equatorially coordinated by four O atoms from two chelating tta ligands. The ligand L propagates the one-dimensional chain structure by serving as a bridging ligand between two Cu octahedra via Cu-N coordinate bonds

The interaction between typically developing students and peers with autism spectrum disorder in regular schools in Ghana : an exploration using the theory of planned behaviour

The purpose of this study is to assess the intention of typically developing peers towards learning in the classroom with students with Autism Spectrum Disorder (ASD). In developing countries, such as Ghana, the body of literature on the relationship between students with disabilities and typically developing peers has been sparsely studied. Using Ajzen’s theory of planned behaviour as a theoretical framework for this study, 516 typically developing students completed four scales representing belief constructs, attitudes, subjective norms, and perceived behavioural controls (self-efficacy), hypothesised to predict behavioural intention. The data were subjected to a t-test, analysis of variance, and structural equation modelling. The modelling confirmed the combining ability of attitude, subjective norms, and perceived behavioural controls to predict intention. We conclude by revealing the need for policymakers to consider designing programmes aimed towards promoting social relationships between students with ASD and typically developing peers