2,113 research outputs found

    Keeping People In Their Homes: Boston’s Anti-Foreclosure Movement

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    While high foreclosure rates devastate low-income communities throughout New England, a grassroots movement in Massachusetts works to keep tenants and owners of foreclosed properties in their homes. The combined efforts of legal services attorneys, neighborhood organizers and community developers empower local residents to combat post-foreclosure displacement and regain their voice in the political process. This inter-organizational network is dissected and each organization profiled

    Combinatorial Properties of Polyiamonds

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    Polyiamonds are plane geometric figures constructed by pasting together equilateral triangles edge-to-edge. It is shown that a diophantine equation involving vertices of degrees 2, 3, 5 and 6 holds for all polyiamonds; then an Eberhard-type theorem is proved, showing that any four-tuple of non-negative integers that satisfies the diophantine equation can be realized geometrically by a polyiamond. Further combinatorial and graph-theoretic aspects of polyiamonds are discussed, including a characterization of those polyiamonds that are three-connected and so three-polytopal, a result on Hamiltonicity, and constructions that use minimal numbers of triangles in realizing four-vectors

    THE IMPACT OF TEACHER LEADERSHIP IN PUBLIC SCHOOLS

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    ABSTRACT The system of education in the United States needs support. Schools are at a constant struggle to maintain a positive climate and culture and retain quality educators. We now live in a world where the grades and performance measures are highly scrutinized. Schools are measured against each other and society wants to see outstanding achievement data from their school systems. Working within Moustakas’s phenomenological approach, this qualitative phenomenological study will investigate the extent to which teacher leadership advances school climate and culture. The study will be conducted in four public schools in North Dakota: Two that have teacher leadership models in place, and two that do not. The study will encompass interviews with teachers at each school. It is my hope that by understanding the influences that teacher leadership has on an organization that an argument can be made to institute teacher leadership structures and best practices into the field of education

    Non-Mendelian Segregation Of The Maize Embryo-Specific Mutation UND-9

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    The maize mutant UND-9 is being studied in our lab as part of a larger study into the genes responsible for embryo development in maize. It is known as an embryo-specific mutant, which causes the embryo of the maize kernel to fail to develop fully while not hindering the development of the endosperm. During this study, it was discovered that the inheritance of this mutation appeared to behave in a manner contrary to the normal laws of Mendelian inheritance. This paper represents a deeper study into the mechanisms of this behavior, analyzing the data collected so far and in particular whether transmission through either the male or female gametophyte has any effect on the presence of the mutation in further generations. We conclude that while some trends in the non-Mendelian behavior are inheritable, we find little evidence of gametophytes playing an abnormal role, and set the stage for future studies with a new hypothetical model

    The corrosion of Ni₃Si alloys in sulfuric acid

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    Hydrogen production from water, the world\u27s most renewable natural resource, can provide an economical and sustainable form of energy for the future. One means to achieve this is with a nuclear reactor-based sulfur-iodine (S-I) thermochemical cycle. Currently there are few materials available, other than precious metals like gold and platinum, that possess the corrosion resistance and mechanical properties required for the sulfuric acid decomposition loop of the S-I process. However, alloys based on Ni₃Si show promise to be a more affordable, corrosion resistant materials option for this technology. In this study, the corrosion behavior of NiSi₂₂ and NiSi₂₀(Nb,Ti)₃ alloys in boiling 70 wt. % sulfuric acid is examined. The mechanism that provides corrosion resistance for these alloys is the formation of an inert SiO₂ surface film which spontaneously grows in oxidizing acid mediums. However, niobium and titanium alloying each have very different effects on the corrosion behavior. The results presented herein indicate that niobium alloying enhances the corrosion resistance of Ni₃Si, whereas titanium alloying has deleterious effects. The changes in corrosion behavior that are imparted by niobium and titanium alloying are linked to the alloy properties, and are the focus of this research --Abstract, page iii

    Genome-wide association study of electrocardiographic and heart rate variability traits: the Framingham Heart Study

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    BACKGROUND: Heritable electrocardiographic (ECG) and heart rate variability (HRV) measures, reflecting pacemaking, conduction, repolarization and autonomic function in the heart have been associated with risks for cardiac arrhythmias. Whereas several rare monogenic conditions with extreme phenotypes have been noted, few common genetic factors contributing to interindividual variability in ECG and HRV measures have been identified. We report the results of a community-based genomewide association study of six ECG and HRV intermediate traits. METHODS: Genotyping using Affymetrix 100K GeneChip was conducted on 1345 related Framingham Heart Study Original and Offspring cohort participants. We analyzed 1175 Original and Offspring participants with ECG data (mean age 52 years, 52% women) and 548 Offspring participants with HRV data (mean age 48 years, 51% women), in relation to 70,987 SNPs with minor allele frequency ≥ 0.10, call rate ≥ 80%, Hardy-Weinberg p-value ≥ 0.001. We used generalized estimating equations to test association of SNP alleles with multivariable-adjusted residuals for QT, RR, and PR intervals, the ratio of low frequency to high frequency power (LF/HFP), total power (TP) and the standard deviation of normal RR intervals (SDNN). RESULTS: Associations at p < 10-3 were found for 117 (QT), 105 (RR), 111 (PR), 102 (LF/HF), 121 (TP), and 102 (SDNN) SNPs. Several common variants in NOS1AP (4 SNPs with p-values < 10-3; lowest p-value, rs6683968, p = 1 × 10-4) were associated with adjusted QT residuals, consistent with our previously reported finding for NOS1AP in an unrelated sample of FHS Offspring and other cohorts. All results are publicly available at NCBI's dbGaP at. CONCLUSION: In the community-based Framingham Heart Study none of the ECG and HRV results individually attained genomewide significance. However, the presence of bona fide QT-associated SNPs among the top 117 results for QT duration supports the importance of efforts to validate top results from the reported scans. Finding genetic variants associated with ECG and HRV quantitative traits may identify novel genes and pathways implicated in arrhythmogenesis and allow for improved recognition of individuals at high risk for arrhythmias in the general population.National Institutes of Health (K23 N01-HC25195); Doris Duke Charitable Foundation Clinical Scientist Developement Award; Pfizer; National Institutes of Health National Center for Research Resources Shared Instrumentation grant (1S10RR163736-01A1

    K-theoretic positivity for matroids

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    Hilbert polynomials have positivity properties under favorable conditions. We establish a similar "K-theoretic positivity" for matroids. As an application, for a multiplicity-free subvariety of a product of projective spaces such that the projection onto one of the factors has birational image, we show that a transformation of its K-polynomial is Lorentzian. This partially answers a conjecture of Castillo, Cid-Ruiz, Mohammadi, and Montano. As another application, we show that the h*-vector of a simplicially positive divisor on a matroid is a Macaulay vector, affirmatively answering a question of Speyer for a new infinite family of matroids

    NEW AND UPDATED RECORDS FOR AMPHIBIANS AND REPTILES IN MINNESOTA, USA

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    Following the publication of the revised edition of “Amphibians and Reptiles in Minnesota” by Moriarty and Hall (2014), we accessioned several new or updated records at the Bell Museum of Natural History (JFBM). Records include digital photographs (accession number preceded by “P”) and audio recordings (accession number preceded by “AUD”). In addition, a subset of these observations were accessioned in www.HerpMapper.org. HerpMapper accession numbers are preceded by “HM” and can be viewed online. Benjamin Lowe verified species determinations. Latitude and longitude coordinates are based on datum WGS 84
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