Intervención nutricional en la cooperativa de la preparatoria San Isidro Mazatepec, municipio de Acatlán de Juárez, Jalisco

El presente documento muestra el diseño e implementación de una propuesta de mejora dentro de la cooperativa de alimentos en la Preparatoria de San Isidro Mazatepec en Tala, Jalisco. Esto con el fin de atender la problemática de desnutrición y obesidad de los alumnos, identificada en el periodo Otoño 2017 como parte de este mismo programa de desarrollo local y fortalecimiento del tejido social. Para lograr este objetivo se tomó como base el cumplimiento total o parcial de las particularidades de una dieta correcta, además de algunas teorías propuestas por la FAO sobre la importancia de la alimentación en escolares. Por ende, se realizó un diagnóstico situacional que consistió en observación, encuestas realizadas a los alumnos y entrevistas dirigidas al director de la preparatoria y la persona encargada de la cooperativa. A partir de esto, se generó un plan de mejora que incluye una capacitación en temas de higiene y manejo de los alimentos, una propuesta de menú saludable y un recetario como entregables.ITESO, A.C

Alanine Represses γ-Aminobutyric Acid Utilization and Induces Alanine Transaminase Required for Mitochondrial Function in Saccharomyces cerevisiae

The γ-aminobutyric acid (GABA) shunt constitutes a conserved metabolic route generating nicotinamide adenine dinucleotide phosphate (NADPH) and regulating stress response in most organisms. Here we show that in the presence of GABA, Saccharomyces cerevisiae produces glutamate and alanine through the irreversible action of Uga1 transaminase. Alanine induces expression of alanine transaminase (ALT1) gene. In an alt1Δ mutant grown on GABA, alanine accumulation leads to repression of the GAD1, UGA1, and UGA2 genes, involved in the GABA shunt, which could result in growth impairment. Induced ALT1 expression and negative modulation of the GABA shunt by alanine constitute a novel regulatory circuit controlling both alanine biosynthesis and catabolism. Consistent with this, the GABA shunt and the production of NADPH are repressed in a wild-type strain grown in alanine, as compared to those detected in the wild-type strain grown on GABA. We also show that heat shock induces alanine biosynthesis and ALT1, UGA1, UGA2, and GAD1 gene expression, whereas an uga1Δ mutant shows heat sensitivity and reduced NADPH pools, as compared with those observed in the wild-type strain. Additionally, an alt1Δ mutant shows an unexpected alanine-independent phenotype, displaying null expression of mitochondrial COX2, COX3, and ATP6 genes and a notable decrease in mitochondrial/nuclear DNA ratio, as compared to a wild-type strain, which results in a petite phenotype. Our results uncover a new negative role of alanine in stress defense, repressing the transcription of the GABA shunt genes, and support a novel Alt1 moonlighting function related to the maintenance of mitochondrial DNA integrity and mitochondrial gene expression.Peer Reviewe

Control of COVID-19 Outbreaks under Stochastic Community Dynamics, Bimodality, or Limited Vaccination

Reaching population immunity against COVID-19 is proving difficult even in countries with high vaccination levels. Thus, it is critical to identify limits of control and effective measures against future outbreaks. The effects of nonpharmaceutical interventions (NPIs) and vaccination strategies are analyzed with a detailed community-specific agent-based model (ABM). The authors demonstrate that the threshold for population immunity is not a unique number, but depends on the vaccination strategy. Prioritizing highly interactive people diminishes the risk for an infection wave, while prioritizing the elderly minimizes fatalities when vaccinations are low. Control over COVID-19 outbreaks requires adaptive combination of NPIs and targeted vaccination, exemplified for Germany for January–September 2021. Bimodality emerges from the heterogeneity and stochasticity of community-specific human–human interactions and infection networks, which can render the effects of limited NPIs uncertain. The authors' simulation platform can process and analyze dynamic COVID-19 epidemiological situations in diverse communities worldwide to predict pathways to population immunity even with limited vaccination.Peer Reviewe

Slides_xsv: Macro and micro pictures of soil samples slides of Tierra del Fuego

Archivos en pdf conteniendo macro y microfotografias realizadas por Ximena Suárez Villagrán de muestras micromorfológicas experimentales y de los yacimientos fueguinos de Túnel VII, Alashawaia y Lanashuaia.Micro and macrophotographies of slides of samples of experimental created soil features and stratigraphic Columns of Túnel VI and Lanashuaia sites.Agencias financiadoras: CSIC, CONICET, Ministerio de Educación y Ciencia (España) y Ministerio de Cultura (España).Peer reviewe

Microtaphonomy in archaeological sites: The use of soil micromorphology to better understand bone taphonomy in archaeological contexts

In archaeozoological studies, taphonomic analyses have focused largely on identification of chemical and mechanical changes of the bones recovered during excavation. The quantification of bone remains is usually made using the number of remains (NR). One of the major drawbacks in the use of the NR method is that it does not take into account the variability in size of faunal remains, from large bones to microscopic fragments. In archaeological sites where no macroscopic bone is preserved due to adverse physico-chemical conditions (e.g. high pH), micromorphology can be used to detect the presence of bones and other animal remains. In addition, microscopic observations provide information on the pre and post-depositional alteration of faunal remains, and allow for a semi-quantitative assessment of microscopic bone fragments. In this sense, micromorphology can be used in support of archaeo-taphonomic studies, which have traditionally overlooked microscopic animal remains. This paper presents some applications of the use of micromorphology to understand bone taphonomy at different archaeological open-air sites, including: (1) a shell midden from Tierra del Fuego, (2) a Brazilian shell mound (sambaqui), (3) an Iberian Middle Palaeolithic site and (4) a Mesolithic campsite in northern Scotland.Raimonda Usai and Annika Burns of the Department of Archaeology, University of York prepared the thin sections from Camas Daraich. The Spanish Ministry of Economy and Competitiveness (former Ministry of Science and Innovation) provided financial support through the I+D projects HAR 2009-07.123 and HAR 2011-24356. Authors a), c) and d) belong to the “Agrest” Research Group sponsored by the Department of Universities and Research of the Catalan Government (AGAUR). Ximena S. Villagran would like to thank the financial support of Fundação de Amparo á Pesquisa do Estado de São Paulo (FAPESP proc. 08/51264-0), Fundación Carolina and Banco Santander. We would like to thank A.B. Marin and M. Moreno, organizers of the 2nd Taphonomy Working Group Meeting held in Santander, for their kind invitation.Peer reviewe

Stratigraphic and spatial variability in shell middens: microfacies identification at the ethnohistoric site Tunel VII (Tierra del Fuego, Argentina)

Based on ethnographic accounts from the eighteenth to the twentieth century, functional areas have been identified within Fueginian shell middens. In this context, archaeological microfacies acquire a functional meaning when the microscopic record is compared to information gathered from ethnology, macroscopic observations made during excavation, and experimental modern analogues. All these lines of evidence were combined for the first time at Tunel VII, an eighteenth/nineteenth century shell midden occupied repeatedly by Yamana people, the last hunter–gatherer–fisher groups of the Beagle Channel. The sampling strategy involved three sets of samples: (1) two stratigraphical columns taken from the hut “entrance” and from a portion of the shell midden (i.e., the surrounding refuse shell ring), (2) thin sections from five hearths representing successive phases of frequentation of the hut, and (3) experimental burnt valves of Mytilus edulis, the main malacological component of the site. Comparison of microfacies from groups (1) and (2) provided microscopic indicators to distinguish between shell dumping areas and occupation surfaces. Comparison of microfacies within columns from group (1) allowed recognizing periods of site abandonment and periods of more intense/longer site frequentation. The experimental samples from M. edulis served as a reference to characterize the five central hearths in terms of maximum burning temperatures reached. Different burning structures were correlated to the season of hut frequentation and to their location (and function) within different portions of the hut. The intra-site micromorphological comparison strategy within a well-documented ethnohistorical context provides valuable indicators for the identification of functional areas in archaeological contexts when ethnographical information is not available.Peer reviewe

Evolutionary Diversification of Alanine Transaminases in Yeast: Catabolic Specialization and Biosynthetic Redundancy

Gene duplication is one of the major evolutionary mechanisms providing raw material for the generation of genes with new or modified functions. The yeast Saccharomyces cerevisiae originated after an allopolyploidization event, which involved mating between two different ancestral yeast species. ScALT1 and ScALT2 codify proteins with 65% identity, which were proposed to be paralogous alanine transaminases. Further analysis of their physiological role showed that while ScALT1 encodes an alanine transaminase which constitutes the main pathway for alanine biosynthesis and the sole pathway for alanine catabolism, ScAlt2 does not display alanine transaminase activity and is not involved in alanine metabolism. Moreover, phylogenetic studies have suggested that ScALT1 and ScALT2 come from each one of the two parental strains which gave rise to the ancestral hybrid. The present work has been aimed to the understanding of the properties of the ancestral type Lacchancea kluyveri LkALT1 and Kluyveromyces lactis KlALT1, alanine transaminases in order to better understand the ScALT1 and ScALT2 evolutionary history. These ancestral -type species were chosen since they harbor ALT1 genes, which are related to ScALT2. Presented results show that, although LkALT1 and KlALT1 constitute ScALT1 orthologous genes, encoding alanine transaminases, both yeasts display LkAlt1 and KlAlt1 independent alanine transaminase activity and additional unidentified alanine biosynthetic and catabolic pathway(s). Furthermore, phenotypic analysis of null mutants uncovered the fact that KlAlt1 and LkAlt1 have an additional role, not related to alanine metabolism but is necessary to achieve wild type growth rate. Our study shows that the ancestral alanine transaminase function has been retained by the ScALT1 encoded enzyme, which has specialized its catabolic character, while losing the alanine independent role observed in the ancestral type enzymes. The fact that ScAlt2 conserves 64% identity with LkAlt1 and 66% with KlAlt1, suggests that ScAlt2 diversified after the ancestral hybrid was formed. ScALT2 functional diversification resulted in loss of both alanine transaminase activity and the additional alanine-independent LkAlt1 function, since ScALT2 did not complement the Lkalt1Δ phenotype. It can be concluded that LkALT1 and KlLALT1 functional role as alanine transaminases was delegated to ScALT1, while ScALT2 lost this role during diversification

Diversification of transcriptional regulation determines subfunctionalization of paralogous branched chain aminotransferases in the yeast Saccharomyces cerevisiae

"Saccharomyces cerevisiae harbors BAT1 and BAT2 paralogous genes that encode branched chain aminotransferases and have opposed expression profiles and physiological roles . Accordingly, in primary nitrogen sources such as glutamine, BAT1 expression is induced, supporting Bat1-dependent valine–isoleucine–leucine (VIL) biosynthesis, while BAT2 expression is repressed. Conversely, in the presence of VIL as the sole nitrogen source, BAT1 expression is hindered while that of BAT2 is activated, resulting in Bat2-dependent VIL catabolism. The presented results confirm that BAT1 expression is determined by transcriptional activation through the action of the Leu3–?-isopropylmalate (?-IPM) active isoform, and uncovers the existence of a novel ?-IPM biosynthetic pathway operating in a put3? mutant grown on VIL, through Bat2-Leu2-Leu1 consecutive action. The classic ?-IPM biosynthetic route operates in glutamine through the action of the leucine-sensitive ?-IPM synthases. The presented results also show that BAT2 repression in glutamine can be alleviated in a ure2? mutant or through Gcn4-dependent transcriptional activation. Thus, when S. cerevisiae is grown on glutamine, VIL biosynthesis is predominant and is preferentially achieved through BAT1; while on VIL as the sole nitrogen source, catabolism prevails and is mainly afforded by BAT2.

In Kluyveromyces lactis a Pair of Paralogous Isozymes Catalyze the First Committed Step of Leucine Biosynthesis in Either the Mitochondria or the Cytosol

Divergence of paralogous pairs, resulting from gene duplication, plays an important role in the evolution of specialized or novel gene functions. Analysis of selected duplicated pairs has elucidated some of the mechanisms underlying the functional diversification of Saccharomyces cerevisiae (S. cerevisiae) paralogous genes. Similar studies of the orthologous pairs extant in pre-whole genome duplication yeast species, such as Kluyveromyces lactis (K. lactis) remain to be addressed. The genome of K. lactis, an aerobic yeast, includes gene pairs generated by sporadic duplications. The genome of this organism comprises the KlLEU4 and KlLEU4BIS paralogous pair, annotated as putative α-isopropylmalate synthases (α-IPMSs), considered to be the orthologs of the S. cerevisiae ScLEU4/ScLEU9 paralogous genes. The enzymes encoded by the latter two genes are mitochondrially located, differing in their sensitivity to leucine allosteric inhibition resulting in ScLeu4-ScLeu4 and ScLeu4-ScLeu9 sensitive dimers and ScLeu9-ScLeu9 relatively resistant homodimers. Previous work has shown that, in a Scleu4Δ mutant, ScLEU9 expression is increased and assembly of ScLeu9-ScLeu9 leucine resistant homodimers results in loss of feedback regulation of leucine biosynthesis, leading to leucine accumulation and decreased growth rate. Here we report that: (i) K. lactis harbors a sporadic gene duplication, comprising the KlLEU4, syntenic with S. cerevisiae ScLEU4 and ScLEU9, and the non-syntenic KlLEU4BIS, arising from a pre-WGD event. (ii) That both, KlLEU4 and KlLEU4BIS encode leucine sensitive α-IPMSs isozymes, located in the mitochondria (KlLeu4) and the cytosol (KlLeu4BIS), respectively. (iii) That both, KlLEU4 or KlLEU4BIS complement the Scleu4Δ Scleu9Δ leucine auxotrophic phenotype and revert the enhanced ScLEU9 transcription observed in a Scleu4Δ ScLEU9 mutant. The Scleu4Δ ScLEU9 growth mutant phenotype is only fully complemented when transformed with the syntenic KlLEU4 mitochondrial isoform. KlLEU4 and KlLEU4BIS underwent a different diversification pathways than that leading to ScLEU4/ScLEU9. KlLEU4 could be considered as the functional ortholog of ScLEU4, since its encoded isozyme can complement both the Scleu4Δ Scleu9Δ leucine auxotrophy and the Scleu4Δ ScLEU9 complex phenotype