82 research outputs found

    Tiling the integers with translates of one finite set

    Get PDF
    A set is said to tile the integers if and only if the integers can be written as a disjoint union of translates of that set. We consider the problem of finding necessary and sufficient conditions for a finite set to tile the integers. For sets of prime power size, it was solved by D. Newman [J. Number Theory 9 (1977), 107--111]. We solve it for sets of size having at most two prime factors. The conditions are always sufficient, but it is unknown whether they are necessary for all finite sets.Comment: 12 page

    In Search of a Match: A Guide for Helping Students Make Informed College Choices

    Get PDF
    This guide is designed for counselors, teachers, and advisers who work with high school students from low-income families and students who are the first in their families to pursue a college education. It offers strategies for helping these students identify, consider, and enroll in "match" colleges -- that is, selective colleges that are a good fit for students based on their academic profiles, financial considerations, and personal needs. Many of the suggestions in this guide are based on insights and lessons learned from the College Match Program, a pilot program that MDRC codeveloped with several partners and implemented in Chicago and New York City to address the problem of "undermatching," or what happens when capable high school students enroll in colleges for which they are academically overqualified or do not apply to college at all. The key lessons of the College Match Program, which are reflected in this guide, are that students are willing to apply to selective colleges when:* They learn about the range of options available to them.* They engage in the planning process early enough to meet college and financial aid deadlines.* They receive guidance, support, and encouragement at all stages.Informed by those key lessons, the guide tracks the many steps in the college search, application, and selection process, suggesting ways to incorporate a match focus at each stage: creating a match culture, identifying match colleges, applying to match colleges, assessing the costs of various college options, selecting a college, and enrolling in college. Because many students question their ability to succeed academically or fit in socially at a selective college, and because they may hesitate to enroll even when they receive good advice and encouragement, the guide offers tips and strategies to help students build the confidence they need to pursue the best college education available to them. Each section also suggests tools and resources in the form of websites and printed materials that counselors, advisers, and students can use, as well as case studies to illustrate the experiences of College Match participants throughout the process

    Cellular automata and Lyapunov exponents

    Full text link
    In this article we give a new definition of some analog of Lyapunov exponents for cellular automata . Then for a shift ergodic and cellular automaton invariant probability measure we establish an inequality between the entropy of the automaton, the entropy of the shift and the Lyapunov exponent

    Proof of the Hyperplane Zeros Conjecture of Lagarias and Wang

    Full text link
    We prove that a real analytic subset of a torus group that is contained in its image under an expanding endomorphism is a finite union of translates of closed subgroups. This confirms the hyperplane zeros conjecture of Lagarias and Wang for real analytic varieties. Our proof uses real analytic geometry, topological dynamics and Fourier analysis.Comment: 25 page

    153. AYA Subspecialty Patient and Parent Views on COVID-19 Vaccination

    Get PDF
    This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Purpose: Adolescents/young adults (AYA) with hematologic and oncologic (heme-onc) conditions are important targets for vaccine outreach because they are at increased risk for complications from COVID-19. AYA patients may also need additional support, as they are transitioning from parent to independent vaccine decision-making. AYA with sickle cell disease (SCD) are of particular concern because a high proportion are African American and experience structural racism in addition to their illness. Our objective was to examine AYA and parent attitudes regarding the COVID-19 vaccine among heme-onc populations. Methods: As part of a larger IRB-approved study, we recruited vaccine decision-makers in pediatric SCD and oncology survivor clinics, including parents of adolescents under 18 years (n=35), AYA patients 18-21 years old (n=21), and parents of AYA patients 18-21 years old (n=14). After informed consent, participants completed a demographic survey and a semi-structured interview regarding their vaccine decision-making process. Example questions included “What do you see as the benefits of the COVID-19 vaccine?” and “What are your concerns about the COVID-19 vaccine?”. Saturation was reached. Interviews were audio recorded, transcribed, and analyzed using thematic analysis. Codes were developed from the literature and early interviews. Examples included “attitudes against vaccine,” “medical mistrust,” “hesitancy,” “vaccine side effects,” and “vaccine interactions with disease process.” Fisher exact statistical tests were performed to analyze quantitative data. Results: In SCD clinic, we recruited 31 index patients (mean age: 15.1±3.5 years; 30 African American and 1 Other or Mixed), yielding 11 AYA and 26 parent interviews. In survivor clinic, we recruited 26 index patients (mean age: 16.0±3.4 years; 20 White, 2 Hispanic or Latinx; 2 Other or Mixed, 1 African American, and 1 Asian), yielding 10 AYA and 23 parent interviews. Out of the total index patients, 8 had already received the vaccine, 13 were planning to receive it, 27 were considering it, and 9 had declined it. There was no clear relationship between patients’ diagnosis (SCD or cancer) and their vaccine decisions nor between the index patient’s age (under or over 18) and their vaccine decisions. A high proportion of participants saw benefits to vaccination, such as lowering personal risk, community benefits of preventing the spread of COVID-19, and a possible return to “normal.” However, many AYA and parent participants also had concerns toward the vaccine, including concerns about short-term side effects and the potential for unknown, long-term effects. Concerns were also voiced about how rapidly the vaccine was developed and misconceptions about the vaccine were common, namely the vaccine causing infertility or increasing one’s susceptibility to contracting COVID-19. Medical mistrust toward either the vaccine or providers was explicitly stated by several participants, the majority of whom were from minoritized groups. Conclusions: COVID-19 vaccines have the potential to protect medically and socially vulnerable AYA, however patient and parent concerns, misconceptions, and mistrust are still prevalent. These data provide insights into the design and implementation of vaccine counseling interviews for AYA subspecialty patients and families

    A glimpse into Thurston's work

    Full text link
    We present an overview of some significant results of Thurston and their impact on mathematics. The final version of this paper will appear as Chapter 1 of the book "In the tradition of Thurston: Geometry and topology", edited by K. Ohshika and A. Papadopoulos (Springer, 2020)

    Why Does Exercise “Triggerâ€? Adaptive Protective Responses in the Heart?

    Get PDF
    Numerous epidemiological studies suggest that individuals who exercise have decreased cardiac morbidity and mortality. Pre-clinical studies in animal models also find clear cardioprotective phenotypes in animals that exercise, specifically characterized by lower myocardial infarction and arrhythmia. Despite the clear benefits, the underlying cellular and molecular mechanisms that are responsible for exercise preconditioning are not fully understood. In particular, the adaptive signaling events that occur during exercise to “trigger� cardioprotection represent emerging paradigms. In this review, we discuss recent studies that have identified several different factors that appear to initiate exercise preconditioning. We summarize the evidence for and against specific cellular factors in triggering exercise adaptations and identify areas for future study

    The challenge of articulating human rights at an LGBT ‘mega-event’: a personal reflection on Sao Paulo Pride 2017

    Get PDF
    © 2017 Informa UK Limited, trading as Taylor & Francis Group. This paper brings together Critical Event Studies (CES) and a reflexive/narrative autoethnographic approach in order to stimulate a debate around the commodification of public space, and the management of mega-events of dissent. This is achieved using the example of the researcher’s participation in the 2017 Sao Paulo Pride. Sao Paulo Pride is one of the largest LGBT demonstrations in the world. However, corporate interests in the event have commodified dissent in order to commercialise ‘otherness’, and the city has absorbed the demonstration into its cultural offer as a global brand. The confluence of these factors produces a pattern of place dressing and erasure that depoliticise the event and undermines its capacity to effectively articulate human rights. Currently Brazil has some of the most liberal LGBT laws of any South American state, yet recently Lesbian, Gay, Bisexual and Transgender (LGBT)/Sexual Orientation and Gender Identity (SOGI) human rights have been threatened by a rapid rise in hate crime and the emergence of an evangelical Christian right in state and regional assemblies. Within such a context the need to revive the roots of Pride as an articulation of otherness that demands recognition, and as a robust defence of human rights for the LGBT/SOGI community, is more pressing than ever

    Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas

    Get PDF
    © The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.info:eu-repo/semantics/publishedVersio
    corecore