Linear Size Optimal q-ary Constant-Weight Codes and Constant-Composition Codes

An optimal constant-composition or constant-weight code of weight $w$ has linear size if and only if its distance $d$ is at least $2w-1$. When $d\geq 2w$, the determination of the exact size of such a constant-composition or constant-weight code is trivial, but the case of $d=2w-1$ has been solved previously only for binary and ternary constant-composition and constant-weight codes, and for some sporadic instances. This paper provides a construction for quasicyclic optimal constant-composition and constant-weight codes of weight $w$ and distance $2w-1$ based on a new generalization of difference triangle sets. As a result, the sizes of optimal constant-composition codes and optimal constant-weight codes of weight $w$ and distance $2w-1$ are determined for all such codes of sufficiently large lengths. This solves an open problem of Etzion. The sizes of optimal constant-composition codes of weight $w$ and distance $2w-1$ are also determined for all $w\leq 6$, except in two cases.Comment: 12 page

SqFreeEVAL: An (almost) optimal real-root isolation algorithm

Let f be a univariate polynomial with real coefficients, f in R[X]. Subdivision algorithms based on algebraic techniques (e.g., Sturm or Descartes methods) are widely used for isolating the real roots of f in a given interval. In this paper, we consider a simple subdivision algorithm whose primitives are purely numerical (e.g., function evaluation). The complexity of this algorithm is adaptive because the algorithm makes decisions based on local data. The complexity analysis of adaptive algorithms (and this algorithm in particular) is a new challenge for computer science. In this paper, we compute the size of the subdivision tree for the SqFreeEVAL algorithm. The SqFreeEVAL algorithm is an evaluation-based numerical algorithm which is well-known in several communities. The algorithm itself is simple, but prior attempts to compute its complexity have proven to be quite technical and have yielded sub-optimal results. Our main result is a simple O(d(L+ln d)) bound on the size of the subdivision tree for the SqFreeEVAL algorithm on the benchmark problem of isolating all real roots of an integer polynomial f of degree d and whose coefficients can be written with at most L bits. Our proof uses two amortization-based techniques: First, we use the algebraic amortization technique of the standard Mahler-Davenport root bounds to interpret the integral in terms of d and L. Second, we use a continuous amortization technique based on an integral to bound the size of the subdivision tree. This paper is the first to use the novel analysis technique of continuous amortization to derive state of the art complexity bounds

New Constant-Weight Codes from Propagation Rules

This paper proposes some simple propagation rules which give rise to new binary constant-weight codes.Comment: 4 page

Wendigos, Eye Killers, Skinwalkers: The Myth of the American Indian Vampire and American Indian “Vampire” Myths

Drawing on American Indian myths and folklore that previous scholarship has placed into direct relationship to the Anglo-European vampire narrative, and on recent U.S. mainstream commodifications of these myths, my paper traces and contextualizes the two oppositional yet intimately linked narratives of American Indian vampirism ensuing today: the commodified image of the “Indian” vampire and the renegotiated vampire tropes created by American Indian authors and filmmakers

Mental health nurses’ attitudes, experience, and knowledge regarding routine physical healthcare:systematic, integrative review of studies involving 7,549 nurses working in mental health settings

Background: There has been a recent growth in research addressing mental health nurses’ routine physical healthcare knowledge and attitudes. We aimed to systematically review the empirical evidence about i) mental health nurses’ knowledge, attitudes, and experiences of physical healthcare for mental health patients, and ii) the effectiveness of any interventions to improve these aspects of their work.Methods: Systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Multiple electronic databases were searched using comprehensive terms. Inclusion criteria: English language papers recounting empirical studies about: i) mental health nurses’ routine physical healthcare-related knowledge, skills, experience, attitudes, or training needs; and ii) the effectiveness of interventions to improve any outcome related to mental health nurses' delivery of routine physical health care for mental health patients. Effect sizes from intervention studies were extracted or calculated where there was sufficient information. An integrative, narrative synthesis of study findings was conducted.Results: Fifty-one papers covering studies from 41 unique samples including 7,549 mental health nurses in 14 countries met inclusion criteria. Forty-two (82.4%) papers were published since 2010. Eleven were intervention studies; 40 were cross-sectional. Observational and qualitative studies were generally of good quality and establish a baseline picture of the issue. Intervention studies were prone to bias due to lack of randomisation and control groups but produced some large effect sizes for targeted education innovations. Comparisons of international data from studies using the Physical Health Attitudes Scale for Mental Health Nursing revealed differences across the world which may have implications for different models of student nurse preparation.Conclusions: Mental health nurses' ability and increasing enthusiasm for routine physical healthcare has been highlighted in recent years. Contemporary literature provides a base for future research which must now concentrate on determining the effectiveness of nurse preparation for providing physical health care for people with mental disorder, determining the appropriate content for such preparation, and evaluating the effectiveness both in terms of nurse and patient- related outcomes. At the same time, developments are needed which are congruent with the needs and wants of patients

Singaporean mothers' perception of their three-year-old child's weight status: A cross-sectional study

Singapore National Research FoundationFull Author List as below: Cheng T.S.; Cheng T.; Loy S.; Cheung Y.; Chan J.; Tint M.; Godfrey K.; Gluckman P.; Kwek K.; Saw S.; Chong Y.; Lee Y.; Yap F.; Lek N.; Sheppard A.; Chinnadurai A.; Goh A.; Rifkin-Graboi A.; Qiu A.; Biswas A.; Lee B.; Broekman B.; Quah B.; Shuter B.; Chng C.; Ngo C.; Hsu S.; Bong C.; Henry C.; Chee C.; Fok D.; Yeo G.; Inskip H.; Chen H.; Van Bever H.; Magiati I.; Wong I.; Lau I.; Kapur J.; Richmond J.; Holbrook J.; Gooley J.; Tan K.; Niduvaje K.; Singh L.; Su L.; Daniel L.; Shek L.; Fortier M.; Hanson M.; Chong M.; Rauff M.; Chua M.; Meaney M.; Teoh O.; Wong P.; Agarwal P.; Van Dam R.; Rebello S.; Chong S.; Cai S.; Soh S.; Lim S.; Rajadurai V.; Stunkel W.; Han W.; Pang W.; Goh Y.; Chan Y.</p

Mobile phone dependence, social support and impulsivity in Chinese university students

This study examined the frequency of mobile phone dependence in Chinese university students and explored its association with social support and impulsivity. Altogether, 909 university students were consecutively recruited from a large university in China. Mobile phone use, mobile phone dependence, impulsivity, and social support were measured with standardized instruments. The frequency of possible mobile phone use and mobile phone dependence was 78.3% and 7.4%, respectively. Multinomial logistic regression analyses revealed that compared with no mobile phone dependence, possible mobile phone dependence was significantly associated with being male (p = 0.04, OR = 0.7, 95% CI: 0.4–0.98), excessive mobile phone use (p \u3c 0.001, OR = 1.2, 95% CI: 1.09–1.2), and impulsivity (p \u3c 0.001, OR = 1.05, 95% CI: 1.03–1.06), while mobile phone dependence was associated with length of weekly phone use (p = 0.01, OR = 2.5, 95% CI: 1.2–5.0), excessive mobile phone use (p \u3c 0.001, OR = 1.3, 95% CI: 1.2–1.4), and impulsivity (p \u3c 0.001, OR = 1.08, 95% CI: 1.05–1.1). The frequency of possible mobile phone dependence and mobile phone dependence was high in this sample of Chinese university students. A significant positive association with impulsivity was found, but not with social support

Product Construction of Affine Codes

Binary matrix codes with restricted row and column weights are a desirable method of coded modulation for power line communication. In this work, we construct such matrix codes that are obtained as products of affine codes - cosets of binary linear codes. Additionally, the constructions have the property that they are systematic. Subsequently, we generalize our construction to irregular product of affine codes, where the component codes are affine codes of different rates.Comment: 13 pages, to appear in SIAM Journal on Discrete Mathematic