Conformal embeddings in affine vertex superalgebras

This paper is a natural continuation of our previous work on conformal embeddings of vertex algebras [6], [7], [8]. Here we consider conformal embeddings in simple affine vertex superalgebra $V_k(\mathfrak g)$ where $\mathfrak g=\mathfrak g_{\bar 0}\oplus \mathfrak g_{\bar 1}$ is a basic classical simple Lie superalgebras. Let $\mathcal V_k (\mathfrak g_{\bar 0})$ be the subalgebra of $V_k(\mathfrak g)$ generated by $\mathfrak g_{\bar 0}$. We first classify all levels $k$ for which the embedding $\mathcal V_k (\mathfrak g_{\bar 0})$ in $V_k(\mathfrak g)$ is conformal. Next we prove that, for a large family of such conformal levels, $V_k(\mathfrak g)$ is a completely reducible $\mathcal V_k (\mathfrak g_{\bar 0})$--module and obtain decomposition rules. Proofs are based on fusion rules arguments and on the representation theory of certain affine vertex algebras. The most interesting case is the decomposition of $V_{-2} (osp(2n +8 \vert 2n))$ as a finite, non simple current extension of $V_{-2} (D_{n+4}) \otimes V_1 (C_n)$. This decomposition uses our previous work [10] on the representation theory of $V_{-2} (D_{n+4})$.Comment: Latex file, 45 pages, to appear in Advances in Mathematic

On coset vertex algebras with central charge 1

We present a coset realization of the vertex operator algebra $V_L ^+$ with central charge $1$. We investigate the vertex operator algebra $V_{Z sqrt{2n}} ^+$ (resp. $V_{2Z sqrt{2n+1}} ^+$) as a vertex subalgebra of $L_{D_n ^{(1)}}(Lambda _0) otimes L_{D_n ^{(1)}}(Lambda _0)$ (resp. $L_{B_n ^{(1)}}(Lambda _0) otimes L_{B_n ^{(1)}}(Lambda _0)$). Our construction is based on the boson-fermion correspondence and certain conformal embeddings

Representations of certain non-rational vertex operator algebras of affine type

In this paper we study a series of vertex operator algebras of integer level associated to the affine Lie algebra $A_{\ell}^{(1)}$. These vertex operator algebras are constructed by using the explicit construction of certain singular vectors in the universal affine vertex operator algebra $N(n-2,0)$ at the integer level. In the case $n=1$ or $l=2$, we explicitly determine Zhu's algebras and classify all irreducible modules in the category $\mathcal{O}$. In the case $l=2$, we show that the vertex operator algebra $N(n-2,0)$ contains two linearly independent singular vectors of the same conformal weight.Comment: 15 pages, LaTeX; final version, to appear in J. Algebr

Z dimetilhidrazinom inducirani tumorji debelega črevesa in danke pri podgani

Animal models of colorectal carcinogenesis represent invaluable research tool for investigating colorectal cancer (CRC). Experimentally induced tumours in laboratory animals provide opportunity for studying certain aspects of tumoursthat cannot be effectively studied in humans. Significant information on human CRC aetiology or factors influencing it has derived from studies using dimethylhydrazine (DMH) model that is one of the experimental models appreciated for its morphological similarity to human CRC. Today, DMH model represents useful research tool for the studies of colon carcinogens and chemopreventive agents. The review offers insight into morphogenesis and genetic alterations of DMH induced colorectal epithelial tumours in rats.Živalski modeli so pri raziskavah raka na debelem črevesju in danki nepogrešljivi, saj omogočajo raziskovanje in testiranje številnih dejavnikov, ki jih ni mogoče neposredno ugotavljati pri ljudeh. Edinega izmed živalskih modelov raka na debelem črevesju in danki predstavljajo z dimetilhidrazinom (DMH) inducirane podgane, ki razvijejo tumorje debelega črevesa in danke zelo podobne humanim. S člankom želimo predstaviti morfološke in genetske spremembetega modela, ki je veliko prispeval k današnjemu poznavanju etioloških in drugih dejavnikov, ki vplivajo na nastanek in razvoj raka. Danespa je nepogrešljiv pri raziskavah črevesnih karcinogenov in kemopreventivnih substanc

The Role of TNF in the Pathogenesis of Inflammatory Bowel Disease

Tumor necrosis factor (TNF) is a pleotropic cytokine involved in a wide range of pathological processes, including inflammatory bowel disease (IBD). In the past, TNF was recognized as a pro-inflammatory cytokine with deleterious effects. This has led to the development of anti-TNF drugs, which revolutionized the treatment of inflammatory disorders such as Crohn’s disease. However, in the past 20 years, clinical studies have shown that anti-TNF drugs are not always effective. Moreover, in some rare cases, anti-TNF drugs can even cause an aggravation of the disease. Nowadays, there is increasing evidence that TNF is not only detrimental but can also play an important role in health and the maintenance of homeostasis. The aim of this chapter is to briefly summarize the literature demonstrating the complex dichotomous role of TNF in IBD and discuss the role of anti-TNF drugs in the treatment of IBD

Morphological and Molecular Alterations in 1,2 Dimethylhydrazine and Azoxymethane Induced Colon Carcinogenesis in Rats

The dimethyhydrazine (DMH) or azoxymethane (AOM) model is a well-established, well-appreciated, and widely used model of experimental colon carcinogenesis. It has many morphological as well as molecular similarities to human sporadic colorectal cancer (CC), which are summarized and discussed in this paper. In addition, the paper combines present knowledge of morphological and molecular features in the multistep development of CC recognized in the DMH/AOM rat model. This understanding is necessary in order to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH/AOM rat colon carcinogenesis. The DMH/AOM model provides a wide range of options for investigating various initiating and environmental factors, the role of specific dietary and genetic factors, and therapeutic options in CC. The limitations of this model and suggested areas in which more research is required are also discussed

Negative School Factors and Their Influence on Math and Science Achievement in TIMSS 2003

The aim of the presented study was to conduct an analysis of TIMSS 2003 database and to determine how negative school factors, such as aggression, are associated to the mathematical and science achievement of students. The analyses were conducted separately for national and international data. National analyses for Slovenia show significant associations between math and science achievement and the experience of aggressive behavior. Students who experienced aggressive behavior scored lower in math and science, both in the 4 th and 8 th grade. The results of the regression analysis show that negative factors, such as aggressive behavior, are good predictors of educational achievement in Slovenia. International analyses for the selected countries (high and low achieving countries from the whole TIMSS population) confirm that this type of finding is culturally impartial as well as valid for the level of achievement both in math and science