Demonstration of Parallel Processing Computing: A Scalable Linux Personal Computer Cluster Approach

In this paper, we describe an innovative approach to teaching parallel computing concepts in a lab setting using a master and slave cluster of Pentium PCs strapped together using Scyld Corporation\u27s Beowulf software, applying a straightforward, custom written prime number test analytical program. This classroom based parallel processing application serves to illustrate three useful topics for the advanced decision sciences student: 1) the Linux operating system and programming concepts, 2) Beowulf cluster computing, and 3) the importance of Linux based parallel processing using low level PCs to solve complex computing applications. It is likely that the results described here can be replicated at low cost in most academic computing environments, yielding enhanced student understanding and ownership of previously less accessible information systems programming concepts. Further, learning the described cluster computing technology tool may build improved problem solving skills for students faced with large, non-trivial computational requirements. Finally, we believe that the demonstrated approach is inherently scalable, thus, deploying this method in larger and larger clusters would be additionally instructive

AN APPROACH TO THE QUANTITATION OF IMMUNOGENIC ANTIGEN

Using passively administered isotope-labeled anti-KLH to suppress the antibody response of rabbits to KLH, we have attempted to estimate the amount of antigen actually involved in stimulating antibody formation. Single and paired label tracer studies of passively administered anti-KLH IgG indicated that from 0.7 to 2.9 µg were utilized or involved by the antigen in the course of a 90% suppression of the response to 2 mg KLH. Tracer studies of labeled anti-KLH F(ab')2 fragments revealed the retention of from 2 to 3 µg of these fragments in the entire rabbit during a 60% suppression of the response to 1 mg KLH. Based on previously determined ratios of mixtures of KLH and suppressive amounts of anti-KLH in adjuvant, the antibody utilization data were converted to the probable amount of antigen or immunogen involved. It appears that after an injection of 2 mg of KLH approximately 0.2–0.5 µg of antigen persisted and reacted with antibody given 24 hr later. Since all of this persisting, reactive antigen may not be immunogenic, the above estimate of immunogen is probably high, but may serve to establish upper limits for the amounts of immunogen involved in stimulating antibody formation and provide a meaningful frame of reference for antigen tracer studies

Transfer of human systemic lupus erythematosus in severe combined immunodeficient (SCID) mice

To study the role of peripheral blood leukocytes (PBL) in the pathogenesis of human systemic lupus erythematosus (SLE), we transferred PBL from 5 SLE patients into 15 severe combined immunodeficiency (SCID) mice. Such reconstituted mice showed long-term presence of auto-antibodies characteristic of the donor in their sera, as well as human immunoglobulin deposition, and in some cases mouse C3, in the renal glomeruli. SCID mice repopulated with PBLs from normal donors do not develop serologic abnormalities or immunodeposits. It is concluded that human SLE serology and some associated renal changes can be reproduced solely by PBL transferred from afflicted patients, and that SCID-human-SLE mice may serve as an in vivo laboratory model for the study of human SLE

Deaths due to differentiated thyroid cancer: A 46-year perspective

From 1940 to 1986, a total of 798 patients were treated for differentiated thyroid carcinoma. One hundred and seventy-two patients died during the follow-up period: 42 (24.4%) patients from thyroid cancer, 14 (8.1%) from other causes with extensive thyroid cancer present, 75 (43.6%) with no thyroid cancer, and 41 (23.8%) with an unknown status of thyroid cancer . Of the 42 patients dying due to thyroid cancer, 15 were male and 27, female. Mean age at diagnosis was 48.3±17.7 years with one-third of patients age 45 or younger at the time of the initial diagnosis. The primary tumors were large (>4 cm) and 59.5% of the patients had local invasion and/or cervical metastasis. Distant metastases were present in 9 (21.4%) patients at the time of diagnosis . Surgical therapy included total thyroidectomy (72.1%) and limited or radical neck dissection (69.4%). Radioactive iodine ( 131 I) was used to treat residual cancer and/or distant metastasis in 73.8% of the patients. External radiation therapy was used to treat locally advanced or recurrent disease in 52.3% of the patients. Distant metastases and local recurrence were identified earlier in patients with follicular thyroid cancer whose survival time and disease-free interval were significantly shorter ( p < 0.001) than that of patients with papillary neoplasms. However, the survival and disease-free intervals were often very long in both papillary and follicular thyroid cancer deaths . Onset of differentiated thyroid cancer before the age of 40 years does not preclude serious sequelae and death. Since no known histopathologic features can consistently predict outcome, we continue to advocate aggressive treatment of all patients with differentiated thyroid cancer . Entre 1940 et 1986, 798 patients au total ont été traités pour un cancer différencié de la thyroïde. Cent-soixant-douze patients sont morts par la suite: 42 (24.4%) de leur cancer, 14 (8.1%) d'une autre cause alors que des signes d'extension du cancer étaient présents, 75 (43.6%) d'une autre cause sans signe de cancer, et 41 (23.8%) sans qu'on ait pu connaître le stade du cancer. Des 42 patients morts de leur cancer, il y avait 15 hommes et 27 femmes. L'âge moyen au moment du diagnostic était de 48.3±17.7 ans: un tiers des patients avait 45 ans ou moins au moment du diagnostic. Les tumeurs primitives avaient plus de 4 cm et 59.5% des patients présentaient un envahissement local et/ou une métastase cervicale. Les métastases à distance ont été détectées chez 9 (21.4%) patients au moment du diagnostic. Une thyroïdectomie totale a été effectuée chez 72.1% des patients, associée à un curage cervical limité ou radical chez 69.4% des patients. Chez 73.8% des patients on a traité le tissu cancéreux résiduel et/ou des métastases à distance par de l'I 131. La radiothérapie a été utilisée pour traiter les patients présentant une extension importante ou une récidive chez 52.3% des patients. Des métastases à distance et des récidives ont été identifiées précocement chez les patients ayant un cancer folliculaire. Dans ce groupe de patients, la survie et l'intervalle de temps sans maladie étaient significativement plus courts ( p <0.001) que chez les patients ayant un cancer papillaire. Il faut cependant noter que la survie et l'intervalle de temps sans maladie étaient très longs dans les 2 groupes de patients. La découverte d'un cancer différencié de la thyroïde avant l'âge de 40 ans n'est pas un facteur pronostique particulier. Puisqu'il n'y pas de facteur histologique permettant de prévoir l'évolution, nous continuons de préconiser un traitement agressif chez tout patient présentant un cancer différencié de la thyroïde. En el período 1940–1986, un total de 798 pacientes recibieron tratamiento para carcinoma tiroideo; 172 murieron en el curso del seguimiento: 42 (24.4%) por cancer tiroideo, 14 (8.1%) por otras causas pero con presencia de extenso cáncer tiroideo, 75 (43.6%) libres de cáncer tiroideo, y 41 (23.8%) con estado desconocido en cuanto al cancer tiroideo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41283/1/268_2005_Article_BF01655866.pd