Microbial transformation of the sesquiterpene lactone tagitinin C by the fungus Aspergillus terreus

The biotransformation of the sesquiterpene lactone tagitinin C by the fungus Aspergillus terreus MT 5.3 yielded a rare derivative that was elucidated by spectrometric methods. The fungus led to the formation of a different product through an unusual epoxidation reaction between C4 and C5, formation of a C3,C10 ether bridge, and a methoxylation of the C1 of tagitinin C. The chemical structure of the product, namely 1 beta-methoxy-3 alpha-hydroxy-3,10 beta-4,5 alpha-diepoxy-8 beta-isobutyroyloxygermacr-11(13)-en-6 alpha,12-olide, is the same as that of a derivative that was recently isolated from the flowers of a Brazilian population of Mexican sunflower (Tithonia diversifolia), which is the source of the substrate tagitinin C. The in vitro cytotoxic activity of the substrate and the biotransformed product were evaluated in HL-60 cells using an MTT assay, and both compounds were found to be cytotoxic. We show that soil fungi may be useful in the biotransformation of sesquiterpene lactones, thereby leading to unusual changes in their chemical structures that may preserve or alter their biological activities, and may also mimic plant biosynthetic pathways for production of secondary metabolites.

Mini-Mental State Examination performance in frail, pre-frail, and non-frail community dwelling older adults in Ermelino Matarazzo, Sao Paulo, Brazil

Background: Frailty in older adults is a multifactorial syndrome defined by low metabolic reserve, less resistance to stressors, and difficulty in maintaining organic homeostasis due to cumulative decline of multiple physiological systems. The relationship between frailty and cognition remains unclear and studies about Mini-Mental State Examination (MMSE) performance and frailty are scarce. The objective was to examine the association between frailty and cognitive functioning as assessed by the MMSE and its subdomains. Methods: A cross-sectional population-based study (FIBRA) was carried out in Ermelino Matarazzo, a poor subdistrict of the city of Sao Paulo, Brazil. Participants were 384 community dwelling older adults, 65 years and older who completed the MMSE and a protocol to assess frailty criteria as described in the Cardiovascular Health Study (CHS). Results: Frail older adults had significantly worse performance on the MMSE (p < 0.001 for total score). Linear regression analyses showed that the MMSE total score was influenced by age (p < 0.001), education (p < 0.001), family income (p < 0.001), and frailty status (p < 0.036). Being frail was associated more significantly with worse scores in Time Orientation (p < 0.004) and Immediate Memory (p < 0.001). Conclusions: Our data suggest that being frail is associated with worse cognitive performance, as assessed by the MMSE. It is recommended that the assessment of frail older adults should include the investigation of their cognitive status.

Comparative genomic and transcriptome analyses of pathotypes of Xanthomonas citri subsp. citri provide insights into mechanisms of bacterial virulence and host range

Abstract Background Citrus bacterial canker is a disease that has severe economic impact on citrus industries worldwide and is caused by a few species and pathotypes of Xanthomonas. X. citri subsp. citri strain 306 (XccA306) is a type A (Asiatic) strain with a wide host range, whereas its variant X. citri subsp. citri strain Aw12879 (Xcaw12879, Wellington strain) is restricted to Mexican lime. Results To characterize the mechanism for the differences in host range of XccA and Xcaw, the genome of Xcaw12879 that was completed recently was compared with XccA306 genome. Effectors xopAF and avrGf1 are present in Xcaw12879, but were absent in XccA306. AvrGf1 was shown previously for Xcaw to cause hypersensitive response in Duncan grapefruit. Mutation analysis of xopAF indicates that the gene contributes to Xcaw growth in Mexican lime but does not contribute to the limited host range of Xcaw. RNA-Seq analysis was conducted to compare the expression profiles of Xcaw12879 and XccA306 in Nutrient Broth (NB) medium and XVM2 medium, which induces hrp gene expression. Two hundred ninety two and 281 genes showed differential expression in XVM2 compared to in NB for XccA306 and Xcaw12879, respectively. Twenty-five type 3 secretion system genes were up-regulated in XVM2 for both XccA and Xcaw. Among the 4,370 common genes of Xcaw12879 compared to XccA306, 603 genes in NB and 450 genes in XVM2 conditions were differentially regulated. Xcaw12879 showed higher protease activity than XccA306 whereas Xcaw12879 showed lower pectate lyase activity in comparison to XccA306. Conclusions Comparative genomic analysis of XccA306 and Xcaw12879 identified strain specific genes. Our study indicated that AvrGf1 contributes to the host range limitation of Xcaw12879 whereas XopAF contributes to virulence. Transcriptome analyses of XccA306 and Xcaw12879 presented insights into the expression of the two closely related strains of X. citri subsp. citri. Virulence genes including genes encoding T3SS components and effectors are induced in XVM2 medium. Numerous genes with differential expression in Xcaw12879 and XccA306 were identified. This study provided the foundation to further characterize the mechanisms for virulence and host range of pathotypes of X. citri subsp. citri.

Range extensions along western Atlantic for Epialtidae crabs (Brachyura, Majoidea) genera Acanthonyx Latreille, 1828 and Epialtus H. Milne Edwards, 1834

The present study provided information extending the known geographical distribution of three species of majoid crabs, the epialtids Acanthonyx dissimulatus Coelho, 1993, Epialtus bituberculatus H. Milne Edwards, 1834, and E. brasiliensis Dana, 1852. Specimens of both genera from different carcinological collections were studied by comparing morphological characters. We provide new data that extends the geographical distributions of E. bituberculatus to the coast of the states of Paraná and Santa Catarina (Brazil), and offer new records from Belize and Costa Rica. Epialtus brasiliensis is recorded for the first time in the state of Rio Grande do Sul (Brazil), and A. dissimulatus is reported from Quintana Roo, Mexico. The distribution of A. dissimulatus, previously known as endemic to Brazil, has a gap between the states of Espírito Santo and Rio de Janeiro. However, this restricted southern distribution is herein amplified by the Mexican specimens.

Los refuerzos visuales en la educación bilingüe. Experiencias en una escuela de Texas

[ES]Este trabajo presenta tres actividades didácticas y una propuesta de evaluación para mejorar el aprendizaje del vocabulario científico en contextos de educación bilingüe. El presente estudio se basa en la observación realizada en clase por parte de un profesor de Ciencias Naturales y Biología en un programa especial bilingüe para niños mejicanos en una escuela secundaria pública de Texas. [EN] The purpose of this article is to present three teaching activities and an evaluation proposal, in order to enhance science vocabulary learning in bilingual education contexts.The present study is based on the classroom observation made by a Science and Biology teacher in a special bilingual program for Mexican children in a public school in Texas (7th to 9th grade).

Development of instrumental and sensory analytical methods of food obtained by traditional and emerging technologies

The consumer demand for natural, minimally processed, fresh like and functional food has lead to an increasing interest in emerging technologies. The aim of this PhD project was to study three innovative food processing technologies currently used in the food sector. Ultrasound-assisted freezing, vacuum impregnation and pulsed electric field have been investigated through laboratory scale systems and semi-industrial pilot plants. Furthermore, analytical and sensory techniques have been developed to evaluate the quality of food and vegetable matrix obtained by traditional and emerging processes. Ultrasound was found to be a valuable technique to improve the freezing process of potatoes, anticipating the beginning of the nucleation process, mainly when applied during the supercooling phase. A study of the effects of pulsed electric fields on phenol and enzymatic profile of melon juice has been realized and the statistical treatment of data was carried out through a response surface method. Next, flavour enrichment of apple sticks has been realized applying different techniques, as atmospheric, vacuum, ultrasound technologies and their combinations. The second section of the thesis deals with the development of analytical methods for the discrimination and quantification of phenol compounds in vegetable matrix, as chestnut bark extracts and olive mill waste water. The management of waste disposal in mill sector has been approached with the aim of reducing the amount of waste, and at the same time recovering valuable by-products, to be used in different industrial sectors. Finally, the sensory analysis of boiled potatoes has been carried out through the development of a quantitative descriptive procedure for the study of Italian and Mexican potato varieties. An update on flavour development in fresh and cooked potatoes has been realized and a sensory glossary, including general and specific definitions related to organic products, used in the European project Ecropolis, has been drafted.

Analysing the possible influence of transposon TCl4.7 insertion on the function of the genome of Cydia pomonella granulovirus

CpGV-MCp5 is a natural mutant of the Cydia pomonella Granulovirus (Mexican isolate) (CpGV-M) that harbors an insect host transposon termed TCl4.7 in its genome. TCl4.7 is located between the open reading frames Cp15 and Cp16 and separates two homologous regions hr3 and hr4, which have been recently shown to be origins of replication of CpGV-M. The MCp5 has a significant replication disadvantage in the presence of the wild-type CpGV-M. In this study, the possible effects of TCl4.7 transposon insertion on the genome function of its insertion site has been analysed. The role of Cp15 and Cp16 in the context of the virus infection cycle was examined by generating a CpGV-Bacmid (CpBAC) and Cp15 knock-out (CpBACCp15KO) and Cp16 knock-out (CpBACCp16KO) mutants. The mutant CpBACCp15KO was not able to replicate in CM larvae suggesting that Cp15 was essential for virus replication. In contrast, the mutant CpBACCp16KO infected CM larvae and produced viable occlusion bodies (OBs) demonstrating that Cp16 is a non-essential gene for virus in vivo infection of C. pomonella. The temporal transcription of Cp15 and Cp16, as well as of Cp31 (F protein) as a control, was analysed using RT-PCR and quantitative real-time PCR. It suggested a general delay or reduction of gene transcription of MCp5 compared to the parental CpGV-M. Western blot analyses using anti-Cp15 and anti-Cp16 polyclonal antibodies, however, did not show any immuno-reactive response. Thus, a direct influence of TCl4.7 on the expression of Cp15 and Cp16 could not be substantiated. To investigate whether the interruption of hr3 and hr4 palindromes affects the virus replication, two mutant bacmids with a deletion of hr3 and hr4 (CpBAChr3/hr4-KO) and another with an insertion of a Kanamycin resistance cassette between hr3 and hr4 (CpBAChr3-kan-hr4) were generated. Both mutant bacmids replicated and produced infectious virus OBs, which did not significantly differ in their median lethal concentration (LC50) and median survival time (ST50) compared to the parental CpBAC. Interestingly, the mutant CpBAChr3-kan-hr4 was very effectively out-competed by parental CpBAC, when CM larvae were co-infected with known ratios of OBs of CpBAC and the mutant CpBAChr3-kan-hr4. These observations suggested a functional co-operation between hr3 and hr4 which was interrupted by the KanR insertion in CpBAChr3-kan-hr4 and possibly by TCl4.7 transposon insertion in the mutant MCp5. This hypothesis may explain the observed replication disadvantage of the mutants MCp5 and CpBAChr3-kan-hr4 in the presence of the parental viruses CpGV-M and CpBAC, respectively.

El guiño de lo real. Percorsi intertestuali nella narrativa di Cristina Rivera Garza

La tesi si occupa di analizzare la produzione narrativa della scrittrice messicana di frontiera Cristina Rivera Garza. In particolare, si pone l'accento sull'uso della strategia dell'intertestualità. A partire dalle fondamentali teorie classiche di Julia Kristeva, Gérard Genette e molti altri, lo scopo è quello di proporre un nuovo modello interpretativo che possa considerare la peculiarità della letteratura ispano-americana e inglobare la particolarità della proposta narrativa della scrittrice in oggetto. Attraverso l'innovativo studio di Roberto González Echevarría, l'obiettivo è quello di analizzare non solo i rapporti che si stabiliscono tra opere che appartengono al sistema della letteratura, ma anche i produttivi rapporti che si stabiliscono fra testi letterari e testi che non appartengono al sistema della letteratura. In particolare si analizza: a) le relazioni tra Storia e narrazione nel romanzo storico messicano tra XX e XXI secolo; b) le relazioni tra cronaca (considerata come genere tout court e come insieme di notizie giornalistiche) e narrazione nel romanzo poliziesco messicano contemporaneo.

"Dar voce a una voce": diversità e rappresentazione nella letteratura young adult. Proposta di traduzione di Gabi, a Girl in Pieces di Isabel Quintero.

In this dissertation, I will present my translation into Italian of several excerpts from Gabi, A Girl in Pieces, a young adult (YA) novel by Mexican-American author Isabel Quintero, along with examining the issues of diversity and representation in YA literature. This study aims to demonstrate the benefits of multicultural literature for young readers and the importance of publishing stories that reflect the diversity of the world we inhabit. The translation of the novel is accompanied by an analysis of its social, cultural, and literary context. The first chapter provides an overview of Chican@ history, literature, and culture, focusing on the concepts of identity and hybridity. The second chapter describes YA literature and its characteristics, outlines its history, and discusses the value of diverse books in the lives of teenage readers. Additionally, it cites relevant studies and statistics proving the dearth of diverse literature for young readers in the United States. The third chapter focuses specifically on the representation of Latin@s and Chican@s in literature for young readers, examining the main stereotypes that have plagued the depiction of this community and the new perspectives offered by Mexican-American YA authors. In the fourth chapter, I introduce Isabel Quintero and her novel Gabi, A Girl in Pieces, analyzing its plot, style, format, and main themes. In the fifth chapter, I provide my translation, which is then analyzed in the sixth and final chapter. The translation commentary details some of the problems I encountered and the strategies I applied. The sixth chapter also includes some observations on the translation of teenage speech, of multilingual texts, and of children’s and YA literature.

Rates Of Obesity And Incidence Of Diabetes In Hispanics In The United States: An Examination Of The Epidemiological Paradox

Using pooled data from the 2008-2011 National Health Interview Survey and employing multinomial and binomial logistic regression methods, this research examines disparities in rates of obesity and incidence of diabetes between individual Hispanic subgroups in comparison to non-Hispanic whites and blacks. Immigration status(including nativity, duration in the United States, and citizenship status) is hypothesized to play a central role in rates and obesity and incidence of diabetes. Unlike Cuban-Americans, Mexican-Americans, Puerto Ricans, and other Hispanics were more likely to be overweight as well as obese when compared to non-Hispanic whites. Mexican-Americans had the only significance in prevalence of type 2 diabetes in comparison to non-Hispanic whites. Both of these health outcomes are strongly associated with the various immigration variables.

Association of PPARG2 Pro12Ala variant with larger body mass index in Mestizo and Amerindian populations of Mexico.

Previous studies have sought to associate the Pro12Ala variant of the peroxisome proliferator-activated receptor gamma2 (PPARG2) gene with type 2 diabetes, insulin resistance, and obesity, with controversial results. We have determined the Pro12Ala variant frequency in 370 nondiabetic Mexican Mestizo subjects and in five Mexican Amerindian groups and have investigated its possible association with lipid metabolism, insulin serum levels, and obesity in three of these populations. Two independent case-control studies were conducted in 239 nondiabetic individuals: 135 case subjects (BMI > or = 25 kg/m2) and 104 control subjects (BMI < 25 kg/m2). The PPARG2 Ala12 allele frequency was higher in most Amerindian populations (0.17 in Yaquis, 0.16 in Mazahuas, 0.16 in Mayans, and 0.20 in Triquis) than in Asians, African Americans, and Caucasians. The Pro12Ala and Ala12Ala (X12Ala) genotypes were significantly associated with greater BMI in Mexican Mestizos and in two Amerindian groups. X12Ala individuals had a higher risk of overweight or obesity than noncarriers in Mestizos (OR = 3.67; 95% CI, 1.42-9.48; p = 0.007) and in Yaquis plus Mazahuas (OR = 3.21; 95% CI, 1.27-8.11; p = 0.013). Our results provide further support of the association between the PPARG2 Ala12 allele and risk of overweight or obesity in Mestizos and two Amerindian populations from Mexico.

SCN4B-encoded sodium channel beta4 subunit in congenital long-QT syndrome.

BACKGROUND Congenital long-QT syndrome (LQTS) is potentially lethal secondary to malignant ventricular arrhythmias and is caused predominantly by mutations in genes that encode cardiac ion channels. Nearly 25% of patients remain without a genetic diagnosis, and genes that encode cardiac channel regulatory proteins represent attractive candidates. Voltage-gated sodium channels have a pore-forming alpha-subunit associated with 1 or more auxiliary beta-subunits. Four different beta-subunits have been described. All are detectable in cardiac tissue, but none have yet been linked to any heritable arrhythmia syndrome. METHODS AND RESULTS We present a case of a 21-month-old Mexican-mestizo female with intermittent 2:1 atrioventricular block and a corrected QT interval of 712 ms. Comprehensive open reading frame/splice mutational analysis of the 9 established LQTS-susceptibility genes proved negative, and complete mutational analysis of the 4 Na(vbeta)-subunits revealed a L179F (C535T) missense mutation in SCN4B that cosegregated properly throughout a 3-generation pedigree and was absent in 800 reference alleles. After this discovery, SCN4B was analyzed in 262 genotype-negative LQTS patients (96% white), but no further mutations were found. L179F was engineered by site-directed mutagenesis and heterologously expressed in HEK293 cells that contained the stably expressed SCN5A-encoded sodium channel alpha-subunit (hNa(V)1.5). Compared with the wild-type, L179F-beta4 caused an 8-fold (compared with SCN5A alone) and 3-fold (compared with SCN5A + WT-beta4) increase in late sodium current consistent with the molecular/electrophysiological phenotype previously shown for LQTS-associated mutations. CONCLUSIONS We provide the seminal report of SCN4B-encoded Na(vbeta)4 as a novel LQT3-susceptibility gene.

Understanding the link between low self-esteem and depression

Although it is well documented that low self-esteem and depression are related, the precise nature of the relation has been a topic of ongoing debate. We describe several theoretical models concerning the link between self-esteem and depression, and review recent research evaluating the validity of these competing models. Overall, the available evidence provides strong support for the vulnerability model (low self-esteem contributes to depression), weaker support for the scar model (depression erodes self-esteem), and little support for alternative accounts such as the diathesis-stress model. Moreover, the vulnerability model is robust and holds across gender, age, affective-cognitive versus somatic symptoms of depression, European background versus Mexican-origin participants, and clinical versus nonclinical samples. Research on further specifications of the vulnerability model suggests that the effect is (a) partially mediated by rumination, (b) not influenced by other characteristics of self-esteem (i.e., stability and contingency), and (c) driven predominantly by global rather than domain-specific self-esteem. The research has important theoretical implications because it counters the commonly repeated claim that self-esteem has no long-term impact. Moreover, the research has important practical implications, suggesting that depression can be prevented, or reduced, by interventions that improve self-esteem.