162 research outputs found
Oral History Interview of Edward Hartmann (SOH-013)
Edward G. Hartmann, former director of libraries and professor of history, reflects on his thirty-year career at Suffolk University. The interview covers his experiences at Suffolk; his teaching career and methods; his thoughts on the university’s presidents and administrations; and his work as an ethnic historian. He concludes with his thoughts on the progress of Suffolk and his hope for continued high educational standards at the university.https://dc.suffolk.edu/soh/1008/thumbnail.jp
Affine rigidity and conics at infinity
RC is partially supported by NSF grant DMS-1564493. SJG is partially supported by NSF grant DMS-1564473.We prove that if a framework of a graph is neighborhood affine rigid in d-dimensions (or has the stronger property of having an equilibrium stress matrix of rank n — d — 1) then it has an affine flex (an affine, but non Euclidean, transform of space that preserves all of the edge lengths) if and only if the framework is ruled on a single quadric. This strengthens and also simplifies a related result by Alfakih. It also allows us to prove that the property of super stability is invariant with respect to projective transforms and also to the coning and slicing operations. Finally this allows us to unify some previous results on the Strong Arnold Property of matrices.PostprintPeer reviewe
Rigidity for sticky disks
We study the combinatorial and rigidity properties of disc packings with generic radii. We show that a packing of n discs in the plane with generic radii cannot have more than 2n − 3 pairs of discs in contact. The allowed motions of a packing preserve the disjointness of the disc interiors and tangency between pairs already in contact (modelling a collection of sticky discs). We show that if a packing has generic radii, then the allowed motions are all rigid body motions if and only if the packing has exactly 2n − 3 contacts. Our approach is to study the space of packings with a fixed contact graph. The main technical step is to show that this space is a smooth manifold, which is done via a connection to the Cauchy–Alexandrov stress lemma. Our methods also apply to jamming problems, in which contacts are allowed to break during a motion. We give a simple proof of a finite variant of a recent result of Connelly et al. (Connelly et al. 2018 (http://arxiv.org/abs/1702.08442)) on the number of contacts in a jammed packing of discs with generic radii.PostprintPeer reviewe
Contribution of hierarchical clustering techniques to the modeling of the geographic distribution of genetic polymorphisms associated with chronic inflammatory diseases in the Québec population
Objectives:
The purpose of this project was to evaluate the potential of the downward hierarchical clustering analysis (DHCA) for studying genetic heterogeneity, i.e. differences in allele frequency in subpopulations, such as the 15 public health regions of the province of Québec (Canada).
Methods:
The study relied on an anonymized sample of 1,680 individuals who had participated in the Québec Heart Health Survey in 1990-1991. The genotyping of 11 variants in 8 candidate genes known to be involved in chronic inflammatory diseases, namely asthma and cardiovascular diseases, was performed using the amplification refractory mutation system and restriction fragment length polymorphism techniques. Only variants showing an allelic frequency >2% in the Québec Heart Health Survey (n = 8) were selected. DHCA techniques were then applied to model the geographical distribution of these 8 genetic variants in 15 Québec public health regions and to study genetic heterogeneity.
Results:
The DHCA allowed to group public health regions and gene variants on the basis of genetic variability. For both asthma and cardiovascular diseases, 3 significant clusters of public health regions and 1 cluster of gene variants were identified.
Discussion:
This study suggests that DHCA might be useful in studying genetic heterogeneity at the population level and for public health activities
The prevalence of triggers in paediatric migraine: a questionnaire study in 102 children and adolescents
The prevalence and characterization of migraine triggers have not been rigorously studied in children and adolescents. Using a questionnaire, we retrospectively studied the prevalence of 15 predefined trigger factors in a clinic-based population. In 102 children and adolescents fulfilling the Second Edition of The International Headache Classification criteria for paediatric migraine, at least one migraine trigger was reported by the patient and/or was the parents’ interpretation in 100% of patients. The mean number of migraine triggers reported per subject was 7. Mean time elapsed between exposure to a trigger factor and attack onset was comprised between 0 and 3 h in 88 patients (86%). The most common individual trigger was stress (75.5% of patients), followed by lack of sleep (69.6%), warm climate (68.6%) and video games (64.7%). Stress was also the most frequently reported migraine trigger always associated with attacks (24.5%). In conclusion, trigger factors were frequently reported by children and adolescents with migraine and stress was the most frequent
Recommended from our members
1963
Trees for a Beautiful Golf Course by Philip Scott (page 1) The Golf Course\u27s Worst Enemy by Charles Amorim and Hal Haskell (2) Message from the President by James f. Gilligan (2) Turf Management Club News (3) Quotes from 1962 Freshman (4) When I consider How my Night is Spent Leonard Mailloux(5) Protection of a Golf Course by Pay Lucas Jr. (6) Safety - The Superintendents\u27 Responsibility by Gerald Peters (7) Picture - Senior Stockbridge Turf Majors (8) Picture - Freshmen Stockbridge Turf Majors (9) Kansas - In the Transition Zone by Carl Beer (10 Seeds by Don Daigle (11) Picture - Dean F. P. Jeffrey, Dr. W.G. Colby and Director J. R. Beattie (12) Picture - Graduates of Winter School for Turf Managers - 1963 (13) The Effect of Last Year\u27s Weather Upon This Year\u27s Incidence of Turf Insects by John C. Schread (A-1) Labor-Management Relations by Mortimer H. Gavin S.J. (A-4) Massachusetts Labor Laws by Andrew C. SInclair (A-7) Golf Course Budget by John Espey (A-10) Golf Course Budgets by Robert St. Thomas (A-12) Purpose & Method of Budgeting by Leon St. Pierre (A-13) The Committee Chairman, His Duties by Charles Connelly (A-16) Long-range vs. Short-range Planning by George Farber (A-18) The Golf Course Superintendent, His Duties by Sherwood Moore (A-20) The Budget by Leo Kowalski (A-25) Public Relations by Leon St. Pierre (A-26) A Study of WIlt by Harry Meusal (A-28) Specifications for a Method of Putting Green Construction by Alexander Radko (A-33) Management of Kentucky Bluegrass & Grass Mixtures for Turf by F.V. Juska (A-38) What\u27s New in Fertilizers by Geoffrey S. Cornish (A-40) Methylene Ureas by Harvey Stangel (A-42) Plastic Coated Fertilizers by Louis I. Hansen (A-44) The Role of Sewage Sludge by James Latham Jr. (A-49) The Role of Ureaforms in the Turf Fertilizer Industry by Robert T. Miller (A-51) Why Low Phosphorus & Higher Potassium by L. J. Sullivan (A-55) Uptake of Potassium by Evangel Bredakis (A-59) Responsibility of Industry & Community in Land Usage & Plantings by Joseph L. Beasley (A-61) Turf & Other Planting Problems by H. Thurston Handley Jr. (A-65) Weeds & Diseases by Dominic Marini (A-67) General Maintenacne & Equipment by Lewis Hodgkinson (A-68) Fertilizer Problems by William J. Bennett (A-70) Lawn Construction & Insect Problems by herbert C. Fordham (A-71
Down-Regulation of Neogenin Accelerated Glioma Progression through Promoter Methylation and Its Overexpression in SHG-44 Induced Apoptosis
Dependence receptors have been proved to act as tumor suppressors in tumorigenesis. Neogenin, a DCC homologue, well known for its fundamental role in axon guidance and cellular differentiation, is also a dependence receptor functioning to control apoptosis. However, loss of neogenin has been reported in several kinds of cancers, but its role in glioma remains to be further investigated.Western blot analysis showed that neogenin level was lower in glioma tissues than in their matching surrounding non-neoplastic tissues (n = 13, p<0.01). By immunohistochemical analysis of 69 primary and 16 paired initial and recurrent glioma sections, we found that the loss of neogenin did not only correlate negatively with glioma malignancy (n = 69, p<0.01), but also glioma recurrence (n = 16, p<0.05). Kaplan-Meier plot and Cox proportional hazards modelling showed that over-expressive neogenin could prolong the tumor latency (n = 69, p<0.001, 1187.6 ± 162.6 days versus 687.4 ± 254.2 days) and restrain high-grade glioma development (n = 69, p<0.01, HR: 0.264, 95% CI: 0.102 to 0.687). By Methylation specific polymerase chain reaction (MSP), we reported that neogenin promoter was methylated in 31.0% (9/29) gliomas, but absent in 3 kinds of glioma cell lines. Interestingly, the prevalence of methylation in high-grade gliomas was higher than low-grade gliomas and non-neoplastic brain tissues (n = 33, p<0.05) and overall methylation rate increased as glioma malignancy advanced. Furthermore, when cells were over-expressed by neogenin, the apoptotic rate in SHG-44 was increased to 39.7% compared with 8.1% in the blank control (p<0.01) and 9.3% in the negative control (p<0.01).These observations recapitulated the proposed role of neogenin as a tumor suppressor in gliomas and we suggest its down-regulation owing to promoter methylation is a selective advantage for glioma genesis, progression and recurrence. Furthermore, the induction of apoptosis in SHG-44 cells after overexpression of neogenin, indicated that neogenin could be a novel target for glioma therapy
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