374 research outputs found
BF models, Duality and Bosonization on higher genus surfaces
The generating functional of two dimensional field theories coupled to
fermionic fields and conserved currents is computed in the general case when
the base manifold is a genus g compact Riemann surface. The lagrangian density
is written in terms of a globally defined 1-form and a
multi-valued scalar field . Consistency conditions on the periods of
have to be imposed. It is shown that there exist a non-trivial dependence of
the generating functional on the topological restrictions imposed to . In
particular if the periods of the field are constrained to take values , with any integer, then the partition function is independent of the
chosen spin structure and may be written as a sum over all the spin structures
associated to the fermions even when one started with a fixed spin structure.
These results are then applied to the functional bosonization of fermionic
fields on higher genus surfaces. A bosonized form of the partition function
which takes care of the chosen spin structure is obtainedComment: 17 page
HIPE: HMC Instruction Predication Extension Applied on Database Processing
The recent Hybrid Memory Cube (HMC) is a smart memory which includes functional units inside one logic layer of the 3D stacked memory design. In order to execute instructions inside the Hybrid Memory Cube (HMC), the processor needs to send instructions to be executed near data, keeping most of the pipeline complexity inside the processor. Thus, control-flow and data-flow dependencies are all managed inside the processor, in such way that only update instructions are supported by the HMC. In order to solve data-flow dependencies inside the memory, previous work proposed HMC Instruction Vector Extensions (HIVE), which embeds a high number of functional units with a interlock register bank. In this work we propose HMC Instruction Prediction Extensions (HIPE), that supports predicated execution inside the memory, in order to transform control-flow dependencies into data-flow dependencies. Our mechanism focus on removing the high latency iteration between the processor and the smart memory during the execution of branches that depends on data processed inside the memory. In this paper we evaluate a balanced design of HIVE comparing to x86 and HMC executions. After we show the HIPE mechanism results when executing a database workload, which is a strong candidate to use smart memories. We show interesting trade-offs of performance when comparing our mechanism to previous work
Optical Density Of Bone Repair After Implantation Of Homogenous Demineralized Dentin Matrix In Diabetic Rabbits
This research evaluated the bone repair process after implantation of homogenous demineralized dentin matrix (HDDM) in surgical defects in the parietal bone of rabbits with alloxan-induced diabetes, using a polytetrafluorethylene (PTFe) barrier for guided bone regeneration. Thirty-six rabbits were used and divided into four groups: control (C, n = 12), diabetic (D, n = 12, left parietal bone), diabetic with PTFe (DPTFe, same 12 rabbits, right parietal bone), and diabetic with PTFe associated to HDDM (D-PTFe+HDDM, n = 12). Bone defects were created in the parietal bone of the rabbits and the experimental treatments were performed, where applicable. The rabbits were sacrificed after 15, 30, 60 and 90 days. The bone defects were examined radiographically and by optical density (ANOVA and Tukey test, p < .05). The radiographic findings showed that the D-PTFe+HDDM group presented greater radiopacity and better trabecular bone arrangement when compared to that of the C, D and D-PTFe groups. The statistical analysis showed significant differences in the optical density of the newly formed bone among the studied groups. It was possible to conclude that HDDM was biocompatible in diabetic rabbits.223275280Abreu, P.P., Morosolli, A., Araújo, M.M., Carvalho, V.A.P., Gomes, M.F., Effects of autogenous demineralized dentin matrix on dental socket wound healing process in human (2004) Braz Oral Res, 18, p. 52. , SupplCarvalho, V.A.P., Tosello, D.O., Salgado, M.A.C., Gomes, M.F., Histomorphometric analysis of homogenous demineralized dentin matrix as osteopromotive material in rabbit mandibules (2004) Int J Oral Maxillofac Implants, 19 (5), pp. 679-686Gomes, M.F., Anjos, M.J.S., Nogueira, T.O., Catanzaro-Guimarães, S.A., Autogenous demineralized dentin matrix for tissue engineering applications: Radiographic and histomorphometric studies (2002) Int J Oral Maxillofac Implants, 17 (4), pp. 488-497Gomes, M.F., Silva, M.J.S., Nogueira, T.O., Catanzaro-Guimarães, S.A., Histologic evaluation of the osteoinductive property of autogenous demineralized dentin matrix on surgical bone defects in rabbit skulls using human amniotic membrane for guided bone regeneration (2001) Int J Oral Maxillofac Implants, 16 (4), pp. 563-571Guyton, A.C., Hall, J.E., (2006) Insulin, Glucagon, and Diabetes mellitus, pp. 827-840. , Guyton AC, Hall JE. Textbook of Medical Physiology. 11th ed, Elsevier;Fiorellini, J.P., Nevins, M.L., Norkin, A., Weber, H.P., Karimbux, N.Y., The effect of insulin therapy on osseointegration in a diabetic rat model (1999) Clin Oral Implants Res, 10 (5), pp. 362-368Lu, H., Kraut, D., Gerstenfeld, L.C., Graves, D.T., Diabetes interferes with the bone formation by affecting the expression of transcription factors that regulate osteoblast differentiation (2003) Endocrinology, 144 (1), pp. 346-352Nevins, M.L., Karimbux, N.Y., Weber, H.P., Giannobile, W.V., Fiorellini, J.P., Wound healing around endosseous implants in experimental diabetes (1998) Int J Oral Maxillofac Implants, 13 (5), pp. 620-629Claro, F.A., Lima, J.R., Salgado, M.A.C., Gomes, M.F., Porous Polyethylene for tissue engineering applications in diabetic rats treated with calcitonin: Histomorphometric analysis (2005) Int J Oral Maxillofac Implants, 20 (2), pp. 211-219Catanzaro-Guimarães, S.A., Catanzaro Guimarães, B.P., Garcia, R.B., Alle, N., Osteogenic potential of autogenic demineralized dentin implanted in bony defects in dogs (1986) Int J Oral Maxillofac Surg, 15 (2), pp. 160-169Bessho, K., Tagawa, T., Murata, M., Purification of rabbit bone morphogenetic protein derived from bone, dentin, and wound tissue after tooth extraction (1990) J Oral Maxillofac Surg, 48 (2), pp. 162-169Nakashima, M., Induction of dentine in amputated pulp of dogs by recombinant human bone morphogenetic proteins-2 and -4 with collagen matrix (1994) Arch Oral Biol, 39 (12), pp. 1085-1089Catanzaro-Guimarães SA. Possibility to reinforce bone repair with decalcified dentin matrix. In: Gesellschaft für orale Implantologie (ed.). Jahrbuch für Orale Implatologie. Berlin: Quintessenz1993. p. 33-
O157:H7 Shiga Toxin-Producing Escherichia coli Strains Associated with Sporadic Cases of Diarrhea in São Paulo, Brazil
Inst Adolfo Lutz Registro, Sao Paulo, BrazilLab Anal Clin Dr Joao Antonio Vozza, Campinas, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilWeb of Scienc
Emerging Enteropathogenic Escherichia coli Strains?
Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially diarrheagenic
Delivery of Dark Material to Vesta via Carbonaceous Chondritic Impacts
NASA's Dawn spacecraft observations of asteroid (4) Vesta reveal a surface
with the highest albedo and color variation of any asteroid we have observed so
far. Terrains rich in low albedo dark material (DM) have been identified using
Dawn Framing Camera (FC) 0.75 {\mu}m filter images in several geologic
settings: associated with impact craters (in the ejecta blanket material and/or
on the crater walls and rims); as flow-like deposits or rays commonly
associated with topographic highs; and as dark spots (likely secondary impacts)
nearby impact craters. This DM could be a relic of ancient volcanic activity or
exogenic in origin. We report that the majority of the spectra of DM are
similar to carbonaceous chondrite meteorites mixed with materials indigenous to
Vesta. Using high-resolution seven color images we compared DM color properties
(albedo, band depth) with laboratory measurements of possible analog materials.
Band depth and albedo of DM are identical to those of carbonaceous chondrite
xenolith-rich howardite Mt. Pratt (PRA) 04401. Laboratory mixtures of Murchison
CM2 carbonaceous chondrite and basaltic eucrite Millbillillie also show band
depth and albedo affinity to DM. Modeling of carbonaceous chondrite abundance
in DM (1-6 vol%) is consistent with howardite meteorites. We find no evidence
for large-scale volcanism (exposed dikes/pyroclastic falls) as the source of
DM. Our modeling efforts using impact crater scaling laws and numerical models
of ejecta reaccretion suggest the delivery and emplacement of this DM on Vesta
during the formation of the ~400 km Veneneia basin by a low-velocity (<2
km/sec) carbonaceous impactor. This discovery is important because it
strengthens the long-held idea that primitive bodies are the source of carbon
and probably volatiles in the early Solar System.Comment: Icarus (Accepted) Pages: 58 Figures: 15 Tables:
Search for the Rare Decay KL --> pi0 ee
The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay
KL--> pi0ee. This mode is expected to have a significant CP violating
component. The measurement of its branching ratio could support the Standard
Model or could indicate the existence of new physics. This letter reports new
results from the 1999-2000 data set. One event is observed with an expected
background at 0.99 +/- 0.35 events. We set a limit on the branching ratio of
3.5 x 10^(-10) at the 90% confidence level. Combining the results with the
dataset taken in 1997 yields the final KTeV result: BR(KL --> pi0 ee) < 2.8 x
10^(-10) at 90% CL.Comment: 4 pages, three figure
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