On the trace map between absolutely abelian number fields of equal conductor

Let L/K be an extension of absolutely abelian number fields of equal conductor, n. The image of the ring of integers of L under the trace map from L to K is an ideal in the ring of integers in K. We compute the absolute norm of this ideal exactly for any such L/K, thereby sharpening an earlier result of Kurt Girstmair. Furthermore, we define an "adjusted trace map" that allows the proof of Leopoldt's Theorem to be reduced to the cyclotomic case.Comment: 11 pages, 1 figure, uses xypic and amscd. Completely revised version. To appear in Acta Arithmetic

Generalized μ\mu-τ\tau symmetry and discrete subgroups of O(3)

The generalized $\mu$-$\tau$ interchange symmetry in the leptonic mixing matrix $U$ corresponds to the relations: $|U_{\mu i}|=|U_{\tau i}|$ with $i=1,2,3$. It predicts maximal atmospheric mixing and maximal Dirac CP violation given $\theta_{13} \neq 0$. We show that the generalized $\mu$-$\tau$ symmetry can arise if the charged lepton and neutrino mass matrices are invariant under specific residual symmetries contained in the finite discrete subgroups of $O(3)$. The groups $A_4$, $S_4$ and $A_5$ are the only such groups which can entirely fix $U$ at the leading order. The neutrinos can be (a) non-degenerate or (b) partially degenerate depending on the choice of their residual symmetries. One obtains either vanishing or very large $\theta_{13}$ in case of (a) while only $A_5$ can provide $\theta_{13}$ close to its experimental value in the case (b). We provide an explicit model based on $A_5$ and discuss a class of perturbations which can generate fully realistic neutrino masses and mixing maintaining the generalized $\mu$-$\tau$ symmetry in $U$. Our approach provides generalization of some of the ideas proposed earlier in order to obtain the predictions, $\theta_{23}=\pi/4$ and $\delta_{\rm CP} = \pm \pi/2$.Comment: 18 page

Telomere protein complexes and their role in lymphoid malignancies

Telomeres are highly regulated and dynamic complexes that protect the genomic DNA and prevent the end of linear chromosomes from being misrecognized as a broken DNA. Due to the end replication problem, telomeres of somatic cells shorten with each cell division, inducing cell senescence. Telomerase is a reverse transcriptase capable of compensating telomere attrition by adding telomere repeats to the ends of chromosomes. Human telomeres are associated with the shelterin complex which consists of six telomere-associated proteins that specifically bind to telomeric DNA. Alterations or removal of individual shelterin components would lead to telomere uncapping and telomere dysfunction, resulting in cellular senescence and transformation to a malignant state. Another complex of multifunctional proteins, named non-shelterin complex, is thought to prevent telomere degradation and facilitate telomerase-based telomere elongation. As telomerase is highly expressed in most human tumor cells, it is considered an attractive target for new therapeutic strategies. In this review, we will summarize the characteristics of telomeres and telomerase in lymphoid malignancies and discuss the role of telomere-associated proteins in these entities.Fil: Panero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Dos Santos, Patricia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina. Laboratorio de Genética de Neoplasias Linfoides; ArgentinaFil: Slavutsky, Irma Rosa. Laboratorio de Genética de Neoplasias Linfoides; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentin

Use of balloon catheter dilation and steroid-eluting stent in light and severe rhinosinusitis of frontal sinus: a multicenter retrospective randomized study

OBJECTIVE: Frontal sinus surgery has an increased rate of re-stenosis, if compared to other sinuses, that mainly depends on recurrent inflammation and abnormal scarring at the frontal recess; its reduction represents one of the keys of therapeutic success. Balloon catheter dilation (BCD) and implantable sinus stents/spacers represent strategies to improve sinus ventilation respecting the integrity of mucosa and reducing abnormal post-surgical scarring. The purpose of this study is to evaluate the effectiveness, safety and correct indication for the use of BCD and a non-absorbable stent (Relieva Stratus™ MicroFlow spacer) in the management of chronic rhinosinusitis (CRS) of the frontal sinus. PATIENTS AND METHODS: In this multicentric retrospective study we included a population of 76 frontal sinuses with non-polypoid CRS. Forty-one frontal sinuses were treated with BCD alone and 35 with BCD + Spacer. We analysed both radiological (Lund-McKay CT scoring modified by Zienrich) and symptomatologic results (SNOT-20 questionnaire) before surgery and after 12 months, dividing patients in two main groups: group “L” (light/mild frontal CRS) and group “S” (moderate/severe frontal CRS). RESULTS: Our results confirm a good safety and effectiveness of BCD in management of frontal CRS and show a good safety, although without significant effectiveness, of Relieva Stratus™ MicroFlow spacer when added to BCD in the management of light and severe frontal CRS. CONCLUSIONS: BCD is an option in management of frontal CRS; the use of stents/spacers could become a new and effective tool in management of CSR, both in addition to standard therapies and in patients where the use of systemic drugs is contraindicated