278 research outputs found
Characters of admissible representations of the affine superalgebra sl(2|1)
We calculate characters and supercharacters for irreducible, admissible representations of the affine superalgebra sl(2|1) in both the Ramond and Neveu-Schwarz sectors and discuss their modular properties in the special case of level k=-1/2. We also show that the non-degenerate integrable characters coincide with some N=4 superconformal characters
Parafermionic Representation of the Affine Algebra at Fractional Level
The four fermionic currents of the affine superalgebra at
fractional level , u positive integer, are shown to be realised in
terms of a free scalar field, an doublet field and a primary field of
the parafermionic algebra .Comment: 5 pages, Latex 2
Introducción. Qué es el viviente, qué es el animal y qué es el hombre. Los preliminares teóricos de la indagación desde Numenio de Apamea a Proclo
¿Qué es el hombre? Los filósofos de la Antigüedad Tardía afrontan tal cuestión en el marco de una indagación más amplia, orientada a establecer qué es el viviente y a determinar los caracteres a través de los cuales los vivientes particulares se diferencian. La investigación toma inicio poniendo en el terreno nociones heredadas de la tradición clásica. Son éstas la identificación entre vida, movimiento, alteridad e identidad, teorizada por Platón en el Sofista; la noción de «viviente en sí» introducida en el Timeo para cualificar el modelo inteligible; el alma considerada como principio de la vida en el Fedón; el acto del pensamiento como vida de Metafísica XII. Estas nociones son retomadas al interior de un aparato teórico determinado por la ley general según la cual la acción causal se ejerce en una dirección unívoca que procede del principio absoluto de la realidad (el Uno) y se articula en diversos niveles hipostáticos. Firmemente anclado en esta premisa de tipo metafísico y lógico está el esquema jerárquico del ser que, aunque enunciado de diferente manera por varios autores, conduce a tomar todo lo que existe como dotado de vida (zoe) porque la vida, definiendo toda la realidad, se distiende en una continuidad dinámica a partir del principio hasta los límites inferiores del universo; paralelamente también la noción de viviente se extiende a toda la realidad, desde el primer grado del ser hasta aquel que está inmediatamente por encima de la materia. De allí se deriva que los términos «vida» y «viviente» se consideran homónimos. Parafraseando a Aristóteles, Plotino y Porfirio sostienen que la vida se dice «en más sentidos» (Plot. I 4 (46) 3. 18; III 2 (47) 1. 30-37; III 7 (45) 11. 48-50; Porph. Sent. 12), sentidos que ellos determinan introduciendo una jerarquía entre lo anterior (inteligible o incorpóreo) y lo posterior (sensible o corpóreo). A nivel inteligible la vida implica ser e intelecto, los cuales, a su vez, se implican recíprocamente e implican también la vida, y forma con ellos la tríada constitutiva de la segunda hipóstasis, el Intelecto (nous) que se genera por el Uno. En relación con lo sensible, el alma, en cuanto principio de movimiento y de vida, da la vida al cuerpo que anima, de modo que el viviente es un cuerpo dotado de alma.
Infections associated with eating seed sprouts: an international concern.
Recent outbreaks of Salmonella and Escherichia coli O157:H7 infections associated with raw seed sprouts have occurred in several countries. Subjective evaluations indicate that pathogens can exceed 107 per gram of sprouts produced from inoculated seeds during sprout production without adversely affecting appearance. Treating seeds and sprouts with chlorinated water or other disinfectants fails to eliminate the pathogens. A comprehensive approach based on good manufacturing practices and principles of hazard analysis and critical control points can reduce the risk of sprout-associated disease. Until effective measures to prevent sprout-associated illness are identified, persons who wish to reduce their risk of foodborne illness from raw sprouts are advised not to eat them; in particular, persons at high risk for severe complications of infections with Salmonella or E. coli O157:H7, such as the elderly, children, and those with compromised immune systems, should not eat raw sprouts
El alma "en relación" y el alma "en coordinación" El joven Proclo y Teodoro de Asine frente al problema de la metensomatosis de hombre a animal
En el Comentario al Timeo y en la XVI disertación sobre la República, Proclo hace referencia a la solución que él mismo ha dado al problema de la metensomatosis de hombre a animal en su comentario a la Palinodia del Fedro, una obra perdida que se remonta ciertamente a los años juveniles.En este escrito, Proclo ha sostenido que el alma humana migra a animales privados de razón sin por ello unirse realmente a sus cuerpos, apoyándose en la concepción de una doble alma: el alma en coordinación (ἐν κατατάξει) con el cuerpo y aquella en relación (ἐν σχέσει) con el viviente. La primera da vida al cuerpo y forma con él el viviente; por el contrario, la otra no se establece en los cuerpos, sino que se agrega “por relación” a aquella ya presente en el animal. Esta distinción permite conciliar los textos platónicos entre sí: el alma humana no entra en un cuerpo animal sino en un cuerpo ya animado, de tal manera que no es ella quien da vida directamente al cuerpo del animal.Sobre la base de una confrontación con Hermias de Alejandría y con Teodoro de Asine, se propone considerar esta tesis como una solución personal de Proclo, elaborada a partir de la concepción de Teodoro de Asine atestiguada en el testimonio 25 Deuse. Al mismo tiempo, se propone considerar auténtico este testimonio que Deuse considera, en cambio, dudoso.AbstractIn his Commentary on the Timaeus and in the 16th dissertation on the Republic, Proclus refers to the solution he personally provided for the issue of metensomatosis from man to animal in his commentary on the Palinode of the Phaedrus, a lost work which must date back to the author’s early years.In this text, Proclus had argued that the human soul migrates into animals devoid of reason without really uniting with their bodies by drawing upon the idea of a two-fold soul: the soul in coordination (ἐν κατατάξει) with the body and the soul in relation (ἐν σχέσει) with the living being. The former soul gives life to the body, thus engendering the living being; the latter soul instead does not establish itself within the body, but joins the soul which is already present within the animal “by way of relation”. This distinction enables Proclus to reconcile Plato’s texts: the human soul does not enter an animal body, but a body which is already ensouled; hence, it is not the human soul which lends life to the body of the animal.Based on a comparison with Hermias of Alexandria and Theodore of Asine, the paper suggests that the above thesis represents an original solution which Proclus developed starting from a view held by Theodore of Asine and attested in fragment 25 Deuse. At the same time, the paper suggests we regard this fragment, which Deuse considers to be of questionable authenticity, as indeed a genuine one.
Superconformal Algebras and Mock Theta Functions
It is known that characters of BPS representations of extended superconformal
algebras do not have good modular properties due to extra singular vectors
coming from the BPS condition. In order to improve their modular properties we
apply the method of Zwegers which has recently been developed to analyze
modular properties of mock theta functions. We consider the case of N=4
superconformal algebra at general levels and obtain the decomposition of
characters of BPS representations into a sum of simple Jacobi forms and an
infinite series of non-BPS representations.
We apply our method to study elliptic genera of hyper-Kahler manifolds in
higher dimensions. In particular we determine the elliptic genera in the case
of complex 4 dimensions of the Hilbert scheme of points on K3 surfaces K^{[2]}
and complex tori A^{[[3]]}.Comment: 28 page
Breast Cancer Subtypes Can Be Determinant in The Decision Making Process to Avoid Surgical Axillary Staging: A retrospective cohort study
Purpose: The need for performing axillary lymph-node dissection in early
breast cancer when the sentinel lymph node (SLN) is positive has been
questioned in recent years. The purpose of this study was to identify a lowrisk
subgroup of early breast cancer patients in whom surgical axillary
staging could be avoided, and to assess the probability of having a positive
lymph-node (LN).
Methods: We retrospectively evaluated 612 consecutive women affected by
early breast cancer. We considered age, tumour size, histological grade,
vascular invasion, lymphatic invasion and cancer subtype (Luminal A,
Luminal B HER-2+, Luminal B HER-2-, HER-2+, and Triple Negative) as
variables for univariate and multivariate analyses to assess probability of
there being a positive SLN o non-sentinel lymph node (NSLN). Chi-square,
Fisher’s Exact test and Student’s t tests were used to investigate the
relationship between variables; whereas logit models were used to estimate
and quantify the strength of the relationship among some covariates and
SLN or the number of metastases.
Results: A significant positive effect of vascular invasion and lymphatic
invasion, and a negative effect of TN were noted. With respect to positive
NSLN, size alone has a significant (positive) effect on tumour presence, but
focusing on the number of metastases, also age has a (negative) significant
effect.
Conclusion: This work shows correlation between subtypes and the
probability of having positive SLN. Patients not expressing vascular invasion,
lymphatic invasion and, moreover, a triple-negative tumor subtype may be
good candidates for breast conservative surgery without axillary su
Affine sl(2|1) and D(2|1;alpha) as Vertex Operator Extensions of Dual Affine sl(2) Algebras
We discover a realisation of the affine Lie superalgebra sl(2|1) and of the
exceptional affine superalgebra D(2|1;alpha) as vertex operator extensions of
two affine sl(2) algebras with dual levels (and an auxiliary level 1 sl(2)
algebra). The duality relation between the levels is (k+1)(k'+1)=1. We
construct the representation of sl(2|1) at level k' on a sum of tensor products
of sl(2) at level k, sl(2) at level k' and sl(2) at level 1 modules and
decompose it into a direct sum over the sl(2|1) spectral flow orbit. This
decomposition gives rise to character identities, which we also derive. The
extension of the construction to the affine D(2|1;k') at level k is traced to
properties of sl(2)+sl(2)+sl(2) embeddings into D(2|1;alpha) and their relation
with the dual sl(2) pairs. Conversely, we show how the level k' sl(2)
representations are constructed from level k sl(2|1) representations.Comment: 50 pages, Latex2e, 2 figures, acknowledgements adde
The accuracy of sentinel lymph-node biopsy in breast cancer after previous excisional biopsy
Scopo: La biopsia del linfonodo sentinella (BLS) nel carcinoma della mammella con linfonodi
ascellari clinicamente negativi \ue8 considerato la migliore scelta per stadiare il cavo ascellare. Inizialmente una
precedente biopsia escissionale del carcinoma era considerata una controindicazione. Esaminiamo il tasso di
successo della BLS e la incidenza della recidiva a livello ascellare in pazienti con carcinoma della mammella
precedentemente sottoposti a biopsia escissionale del tumore. Pazienti e metodi: 858 pazienti con carcinoma
della mammella sono stati sottoposti a BLS e i pazienti con linfonodi sentinella metastatici a svuotamento
del cavo ascellare; 82 pazienti erano stati sottoposti precedentemente a biopsia escissionale del tumore. Risultati:
Il linfonodo sentinella \ue8 stato identificato nel 100% dei casi, \ue8 risultato indenne nel 74,4% e metastatico
nel 23,1%. La dissezione del cavo ascellare \ue8 stata effettuata in tutti i casi con linfonodi sentinella metastatici
e nel 74% dei casi non si sono ritrovati altri linfonodi ascellari metastatici. Il follow-up mediano \ue8
stato di 63,5 mesi e non si sono osservate recidive ascellari. Conclusioni: L\u2019accuratezza del BLS in pazienti con
carcinoma della mammella sottoposte precedentemente a biopsia escissionale \ue8 uguale a quella dei pazienti
non sottoposti a biopsia.Aim: Sentinel node biopsy (SLNB) is considered to be the standard of care for staging the axilla
in clinically node-negative women with breast cancer. A previous breast excisional biopsy has been considered
a contraindication to the use of SLNB.We examined the success rate of SLN localization and then the
evaluation of the incidence of axillary relapse in patients with breast cancer undergoing excisional biopsy.
Patients and Methods: 858 patients with breast carcinoma underwent a SLNB and only positive sentinel
nodes were submitted to axillary dissection; 82 patients had undergone an excisional biopsy before. Results:
The sentinel node was identified in 100% of cases, it was negative in 74.4% and positive in 23.1%. Complete
axillary dissection was performed in all positive cases, and in 74% of cases no other positive nodes were
found. The follow-up median was 63.5 months and no axillary recurrence was observed. Conclusions: SLNB
accuracy in breast cancer patients who have previously undergone excisional biopsy is comparable with that
in patients undergoing no excisional biopsy, so that it may be considered a standard procedure
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