K→πℓ+ℓ−K \rightarrow \pi \ell^+ \ell^- form factor in the Large-Nc_c and cut-off regularization method

Bardeen-Buras-G\'{e}rard have proposed a large N$_c$ method to evaluate hadronic weak matrix elements to attack for instance the determination of the $\Delta I= \frac{1}{2}$-rule and $\mathrm{Re}(\frac{\epsilon'}{\epsilon})$. Here we test this method to the determination of the form factor parameters $a_+$ and $b_+$ in the decays $K^+ \rightarrow \pi^+ \ell^+ \ell^-$ and $K_S \rightarrow \pi ^0 \ell^+ \ell^-$. The results are encouraging: in particular after a complete treatment of Vector Meson Dominance (VMD).Comment: 9 pages, two columns, 5 figure

A charged Z' to conciliate the apparent disagreement between top-antitop Tevatron forward-backward asymmetry and LHC charge asymmetry

We propose a charged, electrically neutral, and flavour changing Z' model to conciliate the apparent disagreement between the important excess found in the top-antitop Tevatron forward-backward asymmetry and the null -compatible with negative- results found in the LHC charge asymmetry. We show that this model contributes positively to the forward-backward asymmetry, whereas naturally a new cancellation is turned on at the LHC, yielding a null, or even negative, charge asymmetry. We found the region in parameter space that is simultaneously allowed by the stringent Tevatron and LHC observables. We show that the model is safe to atomic parity violation constraints and to tj resonance searches, and propose a possible increase in the Z' width to avoid ttj constraints. We evaluate the constraints to the model, as well as distinctive features in the fore-coming experimental results.Comment: 25 pages, 4 figure

Modification of Loop 1 Affects the Nucleotide Binding Properties of Myo1c, the Adaptation Motor in the Inner Ear

Myo1c is one of eight members of the mammalian myosin I family of actin-associated molecular motors. In stereocilia of the hair cells in the inner ear, Myo1c presumably serves as the adaptation motor, which regulates the opening and closing of transduction channels. Although there is conservation of sequence and structure among all myosins in the N-terminal motor domain, which contains the nucleotide- and actin-binding sites, some differences include the length and composition of surface loops, including loop 1, which lies near the nucleotide-binding domain. To investigate the role of loop 1, we expressed in insect cells mutants of a truncated form of Myo1c, Myo1c1IQ, as well as chimeras of Myo1c1IQ with the analogous loop from other myosins. We found that replacement of the charged residues in loop 1 with alanines or the whole loop with a series of alanines did not alter the ATPase activity, transient kinetics properties, or Ca2+ sensitivity of Myo1c1IQ. Substitution of loop 1 with that of the corresponding region from tonic smooth muscle myosin II (Myo1c1IQ-tonic) or replacement with a single glycine (Myo1c1IQ-G) accelerated the release of ADP from A.M 2?3-fold in Ca2+, whereas substitution with loop 1 from phasic muscle myosin II (Myo1c1IQ-phasic) accelerated the release of ADP 35-fold. Motility assays with chimeras containing a single ?-helix, or SAH, domain showed that Myo1cSAH-tonic translocated actin in vitro twice as fast as Myo1cSAH-WT and 3-fold faster than Myo1cSAH-G. The studies show that changes induced in Myo1c via modification of loop 1 showed no resemblance to the behavior of the loop donor myosins or to the changes previously observed with similar Myo1b chimeras

Leptonic Monotops at LHC

We study the possibility of detecting New Physics (NP) phenomena at the LHC through a new search strategy looking at the monotop (top plus missing energy) signature which is common to a variety of NP models. We focus on the leptonic top decay mode and study the discovery or exclusion reach of the 2012 LHC data for three example models. Contrary to the hadronic mode, in this case the problematic QCD multijet background can be safely neglected. We find that the key kinematic variable to suppress most of the remaining SM backgrounds is the transverse mass of the charged lepton and missing energy. In fact, one could expect that the single-top production measurements already address the monotop signature in this mode. This is however not the case because in the SM single-top production the transverse mass has an end point determined by the W mass, while the NP signals typically have an additional source of missing energy. We compare, under the same conditions, our monotop search strategy with existing single-top measurements and find a considerable improvement in the monotop signature reach.Comment: 21 pages, 6 figure

Efficacy of Prucalopride in bowel cleansing before colonoscopy. Results of a pilot study

Colonoscopy is a crucial diagnostic instrument for colorectal cancer screening and an adequate bowel preparation is definitely decisive for the success of the procedure. Especially in elderly patients, bowel cleansing is considered a big issue, because it is often poorly tolerated for many reasons (like inability to swallow large volume of liquids or unlikable taste); this can cause a suboptimal preparation that may lead to miss a neoplastic lesion. There is relatively little data about how to improve preparation tolerability. The purpose of our pilot study was to analyze the effect of prucalopride (Resolor®), a highly selective serotonin 5HT4 receptor agonist used for chronic constipation for its ability to stimulate gastrointestinal peristalsis, undertaken the day before colonoscopy, followed by half volume of polyethylene glycol solution. We found that this can be a good and safe method to achieve an adequate and better-tolerated colon cleansing

Insulin receptor membrane retention by a traceable chimeric mutant

Background: The insulin receptor (IR) regulates glucose homeostasis, cell growth and differentiation. It has been hypothesized that the specific signaling characteristics of IR are in part determined by ligand-receptor complexes localization. Downstream signaling could be triggered from the plasma membrane or from endosomes. Regulation of activated receptor's internalization has been proposed as the mechanism responsible for the differential isoform and ligand-specific signaling. Results: We generated a traceable IR chimera that allows the labeling of the receptor at the cell surface. This mutant binds insulin but fails to get activated and internalized. However, the mutant heterodimerizes with wild type IR inhibiting its auto-phosphorylation and blocking its internalization. IR membrane retention attenuates AP-1 transcriptional activation favoring Akt activation. Conclusions: These results suggest that the mutant acts as a selective dominant negative blocking IR internalization-mediated signaling.Fil: Giudice, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica; ArgentinaFil: Jares, Elizabeth Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Coluccio Leskow, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentin

Glutathione increase by the n-butanoyl glutathione derivative (GSH-C4) inhibits viral replication and induces a predominant Th1 immune profile in old mice infected with influenza virus

During aging, glutathione (GSH) content declines and the immune system undergoes a deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is associated with GSH depletion, could weaken the host defenses against viral infections. We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of aged mice infected with influenza A PR8/H1N1 virus was studied through the determination of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production and Th1/Th2 cytokine profile. Old mice had lower GSH than young mice in organs. Also the gene expression of endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of proteins, i.e. Nrf2 and PDI, was reduced. Following infection, GSH content remained low and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI expression was upregulated during infection and appeared counterbalanced by GSH-C4. Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral replication and induced a predominant Th1 response. In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus infection by inducing immune response, in particular the Th1 profile

Collider Bounds on Lee-Wick Higgs Bosons

We study the constraints on the Lee-Wick Higgs sector arising from direct collider searches. We work in an effective-field theory framework, where all of the Lee-Wick partners are integrated out, with the sole exception of the Lee-Wick Higgs bosons. The resulting theory is a two-Higgs doublet model where the second doublet has wrong-sign kinetic and mass terms. We include the bounds coming from direct Higgs searches at both LEP and Tevatron using the code HiggsBounds, and show the currently excluded parameter space. We also analyze the prospects of LHC Run-I, finding that with a total integrated luminosity of 5 fb $^{-1}$ and a center-of-mass energy of 7 TeV, most of the parameter space for the SM-like CP-even Higgs will be probed.Comment: 26 pages, 5 figures, matches version published by PR

El Viejo Almacén de Pablo Acosta: un testimonio del patrimonio histórico construido en zona rural, Azul, provincia de Buenos Aires

En el marco de trabajos de investigación geológica realizados en las Sierras de Azul y Chillar, se determinó la existencia en el paraje Pablo Acosta, partido de Azul (provincia de Buenos Aires), de un antiguo almacén de ramos generales hoy día denominado El Viejo Almacén que está siendo resignificado por la familia que lo habita. A modo de pulpería refuncionalizada, la edificación tiene una larga historia enraizada con la llegada del ferrocarril y los primeros asentamientos rurales de la zona. Mediante estudios petrográficos y ataque químico, se caracterizaron muestras de revoques y asiento de ladrillos de los muros de la construcción, determinándose también, algunas propiedades físicas de los ladrillos utilizados. Los resultados indican que en los revoques se emplearon arenas de trituración de composición general granítica, con similitudes petrográficas importantes como para correlacionarlas con las rocas del basamento cristalino ígneo-metamórfico precámbrico explotadas en la zonas de Olavarría / Azul, registrando así, la actividad minera de la época. Esta actividad tuvo sus inicios con las actividades en las canteras del Penal de Sierra Chica, en 1882, aproximadamente. En el caso de la junta y asiento de ladrillo del muro posterior, se utilizaron materiales de naturaleza loessoide (ricos en vidrio volcánico)

Improving basic skills in celiac-like disease diagnosis. A case report

Background: The diagnosis of Coeliac disease (CD) requires a combination of sign/symptoms, positivity of specific antibodies and duodenal histological evidence of villous atrophy. Duodenal villous atrophy, despite representing the CD landmark, is not specific since it is found in many gastrointestinal disorders. Giardiasis is one of the most common human intestinal protozoan infestations in industrialized countries whose histological duodenal mucosa damage could mimic that of CD. The present report shows how a wise clinical and laboratory assessment led us shortly to a correct diagnosis. Case presentation: A 42-year-old outpatient woman without previous significant gastrointestinal diseases, was referred with dyspeptic symptoms, fatigue and mild diarrhea from 4 months. Her first investigations including immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (anti-tTG) and stool parasitological and cultural analysis were negative. An esophagogastroduodenoscopy (EGDS) showed no mucosal alteration. But histology demonstrated a Helicobacter Pylori (HP) pan-gastritis while duodenal mucosa showed villous atrophy consistent with a diagnosis of CD Marsh type 3b. While on gluten-free diet (GFD) the patient didn't experience any improvement of symptoms. Duodenal biopsies were then reviewed showing the presence of trophozoites of Giardia on the luminal surface of the duodenal wall and at the same time, a second stool examination revealed the presence of trophozoites and cysts of Giardia. Treated with metronidazole, 500 mg twice daily for 6 days the patient reduced diarrhea after few days. After about 2 months of GFD she was invited to discontinue it. At the same time stool examination was repeated with negative results. She subsequently performed eradication for Hp with triple therapy (Pylera®). Around 6 months later, the patient did not complain any gastrointestinal symptoms. Serological tests were normal and at a follow-up EGDS, duodenal mucosa had normal histology with normal finger-like villi and absence of Giardia trophozoites. Conclusion: This case report shows how CD diagnosis can sometimes be manifold. Intestinal villous atrophy alone may not automatically establish a diagnosis of CD. In the present case the clinical scenario could be fully explained by giardiasis. Indeed, different diagnostic tools and a multi-step approaches have been used to determine the final correct diagnosis