212 research outputs found

    Keys to reduce earnings management in emerging markets

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    This paper examines earnings quality adapted to International Financial Reporting Standards in Mexican emerging capital market and how investor protection and audit quality to override managers’ incentives to engage in earnings management. We evidence that the new accounting regulation could be considered of high quality financial reporting standard because it is associated with lower earnings management. The analyses also suggest that cross-listed firms have higher quality local generally accepted accounting principles accounting information as measured by earnings management. There is also evidence that earnings of Mexican companies with Big 4 auditors are of higher quality. The results contribute to the ongoing debate on whether high standards are sufficient and effective in countries with weaker investor protection rights

    Comparative Pathogenicity of Lomentospora prolificans (Scedosporium prolificans) Isolates from Mexican Patients

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    We identified 11 Lomentospora prolificans isolates recovered from Mexican patients using phenotypic and molecular characteristics. The identification of isolates was assessed by internal transcribed spacer (ITS rDNA) sequencing. In vitro susceptibility to amphotericin B, fluconazole, voriconazole, posaconazole, caspofungin, anidulafungin and micafungin was determined according to Clinical and Laboratory Standards Institute (CLSI) procedures. Three isolates (07-2239, 11-2242 and 04-2673) were used to induce systemic infection in immunocompetent ICR mice. Survival and tissue burden studies were used as markers of pathogenicity. All of the strains were resistant to every antifungal tested with MIC’s for AmB (8–[8 lg/ml), VRC (16–[16 lg/ml), PSC (16– [16 lg/ml), FLC (64–[64 lg/ml) and echinocandins with MICs C8 lg/ml. One hundred, ninety and sixty percent of the infected mice with the strains 07-2239, 11-2242 and 04-2673 died during the study, respectively. Regarding tissue burden, the highest fungal load of the infected mice was detected in brain followed by spleen and kidney, regardless of the strain

    Evaluación de métodos de extracción de prolina como indicador de osmoprotección en dos especies de la familia chenopodiaceae.

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    El aumento de sales en los suelos representa una notable amenaza para la supervivencia de las plantas, y repercute consecuentemente en los niveles agroalimentarios, disminuyendo la capacidad de producción y cosecha en los suelos agrícolas generando grandes pérdidas, tanto económicas, como biológicas considerando las áreas de cultivo. En la presente investigación se determinó mediante espectrofotometría de luz visible, el contenido de prolina libre en las hojas, tallos y raíces de Suaeda nigra y Atriplex canescens, especies de la familia Chenopodiaceae, extraída por diferentes métodos. Los valores promedio del contenido de este aminoácido para ambas especies van de 25.614 a 2.457 µmoles/mg para S. nigra y A. canescensrespectivamente. Los métodos de extracción no influyeron en el contenido de prolina de S. nigra, mientras que en A. canescens, cuando el extracto fue obtenido por el método de macerado más sonicado con dilución previa, los resultados son más altos y estadísticamente diferentes a los obtenidos cuando la muestra fue extraída únicamente por el método de sonicado y con dilución posterior

    The N-Terminus of GalE Induces tmRNA Activity in Escherichia coli

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    BACKGROUND: The tmRNA quality control system recognizes stalled translation complexes and facilitates ribosome recycling in a process termed 'ribosome rescue'. During ribosome rescue, nascent chains are tagged with the tmRNA-encoded SsrA peptide, which targets tagged proteins for degradation. In Escherichia coli, tmRNA rescues ribosomes arrested on truncated messages, as well as ribosomes that are paused during elongation and termination. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe a new translational pausing determinant that leads to SsrA peptide tagging of the E. coli GalE protein (UDP-galactose 4-epimerase). GalE chains are tagged at more than 150 sites, primarily within distinct clusters throughout the C-terminal domain. These tagging sites do not correspond to rare codon clusters and synonymous recoding of the galE gene had little effect on tagging. Moreover, tagging was largely unaffected by perturbations that either stabilize or destabilize the galE transcript. Examination of GalE-thioredoxin (TrxA) fusion proteins showed that the GalE C-terminal domain is no longer tagged when fused to an N-terminal TrxA domain. Conversely, the N-terminus of GalE induced tagging within the fused C-terminal TrxA domain. CONCLUSIONS/SIGNIFICANCE: These findings suggest that translation of the GalE N-terminus induces subsequent tagging of the C-terminal domain. We propose that co-translational maturation of the GalE N-terminal domain influences ribosome pausing and subsequent tmRNA activity

    Prevalence of high-risk human papillomavirus types in Mexican women with cervical intraepithelial neoplasia and invasive carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Prevalence of high risk (HR) human papillomavirus (HPV) types in the states of San Luis Potosí (SLP) and Guanajuato (Gto), Mexico, was determined by restriction fragment length-polymorphism (RFLP) analysis on the E6 ~250 bp (E6-250) HR-HPV products amplified from cervical scrapings of 442 women with cervical intraepithelial neoplasia and invasive carcinoma (280 from SLP and 192 from Gto). Fresh cervical scrapings for HPV detection and typing were obtained from all of them and cytological and/or histological diagnoses were performed on 383.</p> <p>Results</p> <p>Low grade intraepithelial squamous lesions (LSIL) were diagnosed in 280 cases (73.1%), high grade intraepithelial squamous lesions (HSIL) in 64 cases (16.7%) and invasive carcinoma in 39 cases (10.2%). In the 437 cervical scrapings containing amplifiable DNA, only four (0.9%) were not infected by HPV, whereas 402 (92.0%) were infected HR-HPV and 31 (7.1%) by low-risk HPV. RFLP analysis of the amplifiable samples identified infections by one HR-HPV type in 71.4%, by two types in 25.9% and by three types in 2.7%. The overall prevalence of HR-HPV types was, in descending order: 16 (53.4%) > 31 (15.6%) > 18 (8.9%) > 35 (5.6) > 52 (5.4%) > 33 (1.2%) > 58 (0.7%) = unidentified types (0.7%); in double infections (type 58 absent in Gto) it was 16 (88.5%) > 31 (57.7%) > 35 (19.2%) > 18 (16.3%) = 52 (16.3%) > 33 (2.8%) = 58 (2.8%) > unidentified types (1.0%); in triple infections (types 33 and 58 absent in both states) it was 16 (100.0%) > 35 (54.5%) > 31 (45.5%) = 52 (45.5%) > 18 (27.3%). Overall frequency of cervical lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%). The ratio of single to multiple infections was inversely proportional to the severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types in HSIL and invasive cancer lesions was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%).</p> <p>Conclusion</p> <p>Ninety percent of the women included in this study were infected by HR-HPV, with a prevalence 1.14 higher in Gto. All seven HR-HPV types identifiable with the PCR-RFLP method used circulate in SLP and Gto, and were diagnosed in 99.3% of the cases. Seventy-one percent of HR-HPV infections were due to a single type, 25.9% were double and 2.7% were triple. Overall frequency of lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%), and the ratio of single to multiple infections was inversely proportional to severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types found in HSIL and invasive cancer was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%). Since the three predominant types (16, 31 and 18) cause 77.9% of the HR-HPV infections and immunization against type 16 prevents type 31 infections, in this region the efficacy of the prophylactic vaccine against types 16 and 18 would be close to 80%.</p

    Escucha México: estrategias gráficas y cultura auditiva

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    El PAP Escucha México está en constante búsqueda de implementar entornos incluyentes, el desarrollo de la educación sobre la salud y cultura auditiva, proveer las herramientas necesarias para un confort acústico e informar a la ciudadanía y a nuestra comunidad universitaria, acerca de la discapacidad auditiva. Con una gran empatía, se busca que la sociedad esté más informada y de este modo, desarrollar una conciencia acerca de las repercusiones que el ruido puede ocasionar, rasgos negativos irreversibles afectando nuestra salud física y emocional. También nos adentramos a conocer términos científicos y logramos adecuar dicha información para transmitirla de manera clara a las demás personas. Para lograr estas metas, el PAP cuenta con 5 proyectos internos con objetivos específicos buscando siempre un entorno incluyente en los que existen diferentes metodologías de trabajo desde cualitativas hasta cuantitativas, e incluso técnicas de investigación y recopilación de datos. Estos proyectos son: Cruzada contra el Ruido, Mariana Anaya Doll, Redes Sociales Escucha México, Cultura Auditiva (Estrategias de Enseñanza/Aprendizaje) y el Segundo Encuentro de Cultura Auditiva. Cada proyecto tiene un propósito en específico, así como diferentes áreas de trabajo que proveen manejo de redes sociales, investigación e incluso apoya a terceros como Mariana Anaya. Parte fundamental como individuos es reconocer nuestro papel dentro de nuestro entorno y por consecuencia, responder de manera correcta a la corresponsabilidad que cada uno de nosotros tenemos en injerencia a actuar de manera responsable en nuestra sociedad. Por ende, estamos comprometidos y abiertos a la apertura de diálogos, información y de nuevas tendencias, para así lograr un mayor alcance con fines educativos y de comunicación con base a la inclusión y el respeto social.ITESO, A.C

    Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

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    BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption

    Disease Severity in Patients Infected with Leishmania mexicana Relates to IL-1β

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    Leishmania mexicana can cause both localized (LCL) and diffuse (DCL) cutaneous leishmaniasis, yet little is known about factors regulating disease severity in these patients. We analyzed if the disease was associated with single nucleotide polymorphisms (SNPs) in IL-1β (−511), CXCL8 (−251) and/or the inhibitor IL-1RA (+2018) in 58 Mexican mestizo patients with LCL, 6 with DCL and 123 control cases. Additionally, we analyzed the in vitro production of IL-1β by monocytes, the expression of this cytokine in sera of these patients, as well as the tissue distribution of IL-1β and the number of parasites in lesions of LCL and DCL patients. Our results show a significant difference in the distribution of IL-1β (−511 C/T) genotypes between patients and controls (heterozygous OR), with respect to the reference group CC, which was estimated with a value of 3.23, 95% CI = (1.2, 8.7) and p-value = 0.0167), indicating that IL-1β (−511 C/T) represents a variable influencing the risk to develop the disease in patients infected with Leishmania mexicana. Additionally, an increased in vitro production of IL-1β by monocytes and an increased serum expression of the cytokine correlated with the severity of the disease, since it was significantly higher in DCL patients heavily infected with Leishmania mexicana. The distribution of IL-1β in lesions also varied according to the number of parasites harbored in the tissues: in heavily infected LCL patients and in all DCL patients, the cytokine was scattered diffusely throughout the lesion. In contrast, in LCL patients with lower numbers of parasites in the lesions, IL-1β was confined to the cells. These data suggest that IL-1β possibly is a key player determining the severity of the disease in DCL patients. The analysis of polymorphisms in CXCL8 and IL-1RA showed no differences between patients with different disease severities or between patients and controls

    Estimating Contact Process Saturation in Sylvatic Transmission of Trypanosoma cruzi in the United States

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    Although it has been known for nearly a century that strains of Trypanosoma cruzi, the etiological agent for Chagas' disease, are enzootic in the southern U.S., much remains unknown about the dynamics of its transmission in the sylvatic cycles that maintain it, including the relative importance of different transmission routes. Mathematical models can fill in gaps where field and lab data are difficult to collect, but they need as inputs the values of certain key demographic and epidemiological quantities which parametrize the models. In particular, they determine whether saturation occurs in the contact processes that communicate the infection between the two populations. Concentrating on raccoons, opossums, and woodrats as hosts in Texas and the southeastern U.S., and the vectors Triatoma sanguisuga and Triatoma gerstaeckeri, we use an exhaustive literature review to derive estimates for fundamental parameters, and use simple mathematical models to illustrate a method for estimating infection rates indirectly based on prevalence data. Results are used to draw conclusions about saturation and which population density drives each of the two contact-based infection processes (stercorarian/bloodborne and oral). Analysis suggests that the vector feeding process associated with stercorarian transmission to hosts and bloodborne transmission to vectors is limited by the population density of vectors when dealing with woodrats, but by that of hosts when dealing with raccoons and opossums, while the predation of hosts on vectors which drives oral transmission to hosts is limited by the population density of hosts. Confidence in these conclusions is limited by a severe paucity of data underlying associated parameter estimates, but the approaches developed here can also be applied to the study of other vector-borne infections
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