Álgebra y Geometría : Una manera de pensar

El presente material es producto de la experiencia en cátedras del área Álgebra y cursos de ingreso y la previa elaboración de apuntes para Álgebra, Cálculo Numérico y Geometría Analítica, Matemática I. Recopila, unifica, amplía y mejora el material existente. Presenta todos los temas de esas asignaturas, con una base teórica sólida, práctica, aplicaciones y motivaciones, integrando y relacionando contenidos. Algunos temas son comunes y de igual nivel en las tres. Otros difieren en profundidad y hay subtemas abordados solo en alguna de ellas. Por ello, sugerimos al estudiante que utilice el libro con diferente recorrido de acuerdo a su interés. Es texto de las materias mencionadas y puede servir de consulta o referencia para las asignaturas Probabilidades, Estadística e inicio para otras del área Álgebra.Facultad de Ciencias Exacta

3′IsomiR Species Composition Affects Reliable Quantification of miRNA/isomiR Variants by Poly(A) RT-qPCR: Impact on Small RNA-Seq Profiling Validation

Small RNA-sequencing (small RNA-seq) has revealed the presence of small RNA-naturally occurring variants such as microRNA (miRNA) isoforms or isomiRs. Due to their small size and the sequence similarity among miRNA isoforms, their validation by RT-qPCR is challenging. We previously identified two miR-31-5p isomiRs-the canonical and a 3 ' isomiR variant (3 ' G addition)-which were differentially expressed between individuals with azoospermia of different origin. Here, we sought to determine the discriminatory capacity between these two closely-related miRNA isoforms of three alternative poly(A) based-RT-qPCR strategies in both synthetic and real biological context. We found that these poly(A) RT-qPCR strategies exhibit a significant cross-reactivity between these miR-31-5p isomiRs which differ by a single nucleotide, compromising the reliable quantification of individual miRNA isoforms. Fortunately, in the biological context, given that the two miRNA variants show changes in the same direction, RT-qPCR results were consistent with the findings of small RNA-seq study. We suggest that miRNA selection for RT-qPCR validation should be performed with care, prioritizing those canonical miRNAs that, in small RNA-seq, show parallel/homogeneous expression behavior with their most prevalent isomiRs, to avoid confounding RT-qPCR-based results. This is suggested as the current best strategy for robust biomarker selection to develop clinically useful tests

Virulence in Mice of a Toxoplasma gondii Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep

[EN] Toxoplasma gondii is an apicomplexan parasite that infects almost all warm-blooded animals. Little is known about how the parasite virulence in mice extrapolates to other relevant hosts. In the current study, in vitro phenotype and in vivo behavior in mice and sheep of a type II T. gondii isolate (TgShSp1) were compared with the reference type II T. gondii isolate (TgME49). The results of in vitro assays and the intraperitoneal inoculation of tachyzoites in mice indicated an enhanced virulence for the laboratory isolate, TgME49, compared to the recently obtained TgShSp1 isolate. TgShSp1 proliferated at a slower rate and had delayed lysis plaque formation compared to TgME49, but it formed more cyst-like structures in vitro. No mortality was observed in adult mice after infection with 1-105 tachyzoites intraperitoneally or with 25-2,000 oocysts orally of TgShSp1. In sheep orally challenged with oocysts, TgME49 infection resulted in sporadically higher rectal temperatures and higher parasite load in cotyledons from ewes that gave birth and brain tissues of the respective lambs, but no differences between these two isolates were found on fetal/lamb mortality or lesions and number of T. gondii-positive lambs. The congenital infection after challenge at mid-pregnancy with TgShSp1, measured as offspring mortality and vertical transmission, was different depending on the challenged host. In mice, mortality in 50% of the pups was observed when a dam was challenged with a high oocyst dose (500 TgShSp1 oocysts), whereas in sheep infected with the same dose of oocysts, mortality occurred in all fetuses. Likewise, mortality of 9 and 27% of the pups was observed in mice after infection with 100 and 25 TgShSp1 oocysts, respectively, while in sheep, infection with 50 and 10 TgShSp1 oocysts triggered mortality in 68 and 66% of the fetuses/lambs. Differences in vertical transmission in the surviving offspring were only found with the lower oocyst doses (100% after infection with 10 TgShSp1 oocysts in sheep and only 37% in mice after infection with 25 TgShSp1 oocysts). In conclusion, virulence in mice of T. gondii type II isolates may not be a good indicator to predict the outcome of infection in pregnant sheepSIRS-S is supported by a fellowship from the Spanish Ministry of Education, Culture, and Sports (MECD), as a part of the Program of Training of University Teaching Staff (FPU, grant number FPU13/03438) and a mobility grant for predoctoral short stays in R+D centers (EST16/0719). DG-E is the recipient of a postdoctoral contract from the Junta de Castilla y León, partially funded by the European Social Fund (European Union). NA-V is the recipient of a predoctoral contract from the Ministerio de Economía, Industria y Competitividad (Ref. BES-2016-076513). This work was supported by the Ministry of Economy and Competitiveness (AGL2016-75935-C2-1-R and C2-2-R), the Community of Madrid, Spain (PLATESA, S2013/ABI2906), Junta de Castilla y León (LE080U16), and a grant of the Swiss National Science Foundation to AH (project No. 310030_165782

El Taller Verde como fuente de aprendizaje e inclusión social

En la ciudad de Mar del Plata funciona el Centro de Día “La Casa del Ángel” cuyos concurrentes poseen discapacidad mental leve, moderada severa y/o motora. Este centro posee entre sus actividades el “Taller de Huerta”. Debido a las inclemencias climáticas y a la dificultad del trabajo al aire libre para este tipo de taller se decidió trabajar interdisciplinariamente entre el equipo terapéutico de la institución y la FCEyN (UNMdP) para solucionar estos inconvenientes. El proyecto se focaliza en la creación y adecuación de un espacio de capacitación denominado ¨TALLER VERDE¨, como lugar de: aprendizaje, fortalecimiento de autoestima, creación en hábitos de autoconsumo, seguridad alimentaria, salud humana, y entrenamiento en prácticas de formación para el auto emprendimiento e inserción social; generando así, un ámbito para aprender a emprender. La creación del TALLER VERDE implicó la adaptación de un espacio para el cultivo de especies hortícolas de plantas en condiciones de invernáculo, y el aprendizaje acerca de su cuidado y seguimiento. Realizar las tareas bajo cubierta facilita el trabajo sostenido a lo largo del año independizándolo de los cambios climáticos estacionales, brindándole a los concurrentes un ¨proyecto de vida¨ sostenible en el tiempo. En la primera etapa se aspira al autoconsumo de la producción hortícola para la elaboración de los alimentos que se proveen en el comedor institucional. Una vez adecuadas las condiciones del invernáculo para el cultivo y de las plantas durante el año, el trabajo consistirá en producir verduras para auto consumo, autoreproducir semilla y mantener las especies vegetales para luego colocar los productos en ferias locales, actividad que contribuirá para el desarrollo y sostenimiento del proyecto. Desde el punto de vista de la innovación, y a través del aporte del grupo de la FCEyN, el cultivo de las plantas implicará la formación acerca de sustratos, nutrientes y biopesticidas, especialmente seleccionados por sus condiciones de practicidad e inocuidad, tanto para el ambiente como la salud humana. Se pretende convertir al Taller-Verde en un espacio innovador y modelo para otros establecimientos, permitiendo generar una actividad educativa sostenida que integre el sentido del trabajo como constitutivo de la identidad personal, y como un elemento de gran potencialidad para generar lazos que integren la diversidad social conjuntamente con la naturaleza y con los productos de la tierra. El TALLER-VERDE constituirá un “laboratorio vivo” en el cual los concurrentes aprenderán, investigarán y experimentarán, desarrollando una cultura emprendedora, trabajando en equipo, planificando y proyectando.

Virulence in Mice of a Toxoplasma gondii Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep

Toxoplasma gondii is an apicomplexan parasite that infects almost all warm-blooded animals. Little is known about how the parasite virulence in mice extrapolates to other relevant hosts. In the current study, in vitro phenotype and in vivo behavior in mice and sheep of a type II T. gondii isolate (TgShSp1) were compared with the reference type II T. gondii isolate (TgME49). The results of in vitro assays and the intraperitoneal inoculation of tachyzoites in mice indicated an enhanced virulence for the laboratory isolate, TgME49, compared to the recently obtained TgShSp1 isolate. TgShSp1 proliferated at a slower rate and had delayed lysis plaque formation compared to TgME49, but it formed more cyst-like structures in vitro. No mortality was observed in adult mice after infection with 1–105 tachyzoites intraperitoneally or with 25–2,000 oocysts orally of TgShSp1. In sheep orally challenged with oocysts, TgME49 infection resulted in sporadically higher rectal temperatures and higher parasite load in cotyledons from ewes that gave birth and brain tissues of the respective lambs, but no differences between these two isolates were found on fetal/lamb mortality or lesions and number of T. gondii-positive lambs. The congenital infection after challenge at mid-pregnancy with TgShSp1, measured as offspring mortality and vertical transmission, was different depending on the challenged host. In mice, mortality in 50% of the pups was observed when a dam was challenged with a high oocyst dose (500 TgShSp1 oocysts), whereas in sheep infected with the same dose of oocysts, mortality occurred in all fetuses. Likewise, mortality of 9 and 27% of the pups was observed in mice after infection with 100 and 25 TgShSp1 oocysts, respectively, while in sheep, infection with 50 and 10 TgShSp1 oocysts triggered mortality in 68 and 66% of the fetuses/lambs. Differences in vertical transmission in the surviving offspring were only found with the lower oocyst doses (100% after infection with 10 TgShSp1 oocysts in sheep and only 37% in mice after infection with 25 TgShSp1 oocysts). In conclusion, virulence in mice of T. gondii type II isolates may not be a good indicator to predict the outcome of infection in pregnant sheep

Post–COVID-19 Conditions Among Children 90 Days After SARS-CoV-2 Infection

IMPORTANCE Little is known about the risk factors for, and the risk of, developing post-COVID-19 conditions (PCCs) among children. OBJECTIVES To estimate the proportion of SARS-CoV-2-positive children with PCCs 90 days after a positive test result, to compare this proportion with SARS-CoV-2-negative children, and to assess factors associated with PCCs. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study, conducted in 36 emergency departments (EDs) in 8 countries between March 7, 2020, and January 20, 2021, included 1884 SARS-CoV-2-positive children who completed 90-day follow-up; 1686 of these children were frequency matched by hospitalization status, country, and recruitment date with 1701 SARS-CoV-2-negative controls. EXPOSURE SARS-CoV-2 detected via nucleic acid testing. MAIN OUTCOMES AND MEASURES Post-COVID-19 conditions, defined as any persistent, new, or recurrent health problems reported in the 90-day follow-up survey. RESULTS Of 8642 enrolled children, 2368 (27.4%) were SARS-CoV-2 positive, among whom 2365 (99.9%) had index ED visit disposition data available; among the 1884 children (79.7%) who completed follow-up, the median age was 3 years (IQR, 0-10 years) and 994 (52.8%) were boys. A total of 110 SARS-CoV-2-positive children (5.8%; 95% CI, 4.8%-7.0%) reported PCCs, including 44 of 447 children (9.8%; 95% CI, 7.4%-13.0%) hospitalized during the acute illness and 66 of 1437 children (4.6%; 95% CI, 3.6%-5.8%) not hospitalized during the acute illness (difference. 5.3%; 95% CI, 2.5%-8.5%). Among SARS-CoV-2-positive children, the most common symptom was fatigue or weakness (21 [1.1%]). Characteristics associated with reporting at least 1 PCC at 90 days included being hospitalized 48 hours or more compared with no hospitalization (adjusted odds ratio [aOR], 2.67 [95% CI, 1.63-4.38]); having 4 or more symptoms reported at the index ED visit compared with 1 to 3 symptoms (4-6 symptoms: aOR, 2.35 [95% CI, 1.28-4.31]; >= 7 symptoms: aOR, 4.59 [95% CI, 2.50 8.44]); and being 14 years of age or older compared with younger than 1 year (aOR, 2.67 [95% CI, 1.43-4.99]). SARS-CoV-2-positive children were more likely to report PCCs at 90 days compared with those who tested negative, both among those who were not hospitalized (55 of 1295 [4.2%; 95% CI, 3.2%-5.5%] vs 35 of 1321[2.7%; 95% CI, 1.9%-3.7%]; difference, 1.6% [95% CI, 0.2%-3.0%]) and those who were hospitalized (40 of 391[10.2%; 95% CI, 7.4%-13.7%] vs 19 of 380 [5.0%; 95% CI, 3.0%-7.7%]; difference, 5.2% [95% CI, 1.5%-9.1%]). In addition, SARS-CoV-2 positivity was associated with reporting PCCs 90 days after the index ED visit (aOR, 1.63 [95% CI, 1.14-2.35]), specifically systemic health problems (eg, fatigue, weakness, fever; aOR, 2.44 [95% CI, 1.19-5.00]). CONCLUSIONS AND RELEVANCE In this cohort study, SARS-CoV-2 infection was associated with reporting PCCs at 90 days in children. Guidance and follow-up are particularly necessary for hospitalized children who have numerous acute symptoms and are older.This studywas supported by grants from the Canadian Institutes of Health Research (operating grant: COVID-19-clinical management); the Alberta Health Services-University of Calgary-Clinical Research Fund; the Alberta Children's Hospital Research Institute; the COVID-19 Research Accelerator Funding Track (CRAFT) Program at the University of California, Davis; and the Cincinnati Children's Hospital Medical Center Division of Emergency Medicine Small Grants Program. Dr Funk is supported by the University of Calgary Eyes-High PostDoctoral Research Fund. Dr Freedman is supported by the Alberta Children's Hospital Foundation Professorship in Child Health andWellness

Internationally-based indicators to measure Agri-food systems sustainability using food sovereignty as a conceptual framework

Agri-food systems are essential not only in achieving food security but also in achieving both social and environmental sustainability. Despite different actors use different frameworks to define and assess food systems sustainability, there is growing consensus on the need to approach them from a complex socio-ecological systems perspective. However, existing frameworks often lack the political dimension in the analysis of food systems outcomes. Food sovereignty has emerged as a proposal that centers the discussion in the entire system putting emphasis on the political aspects of food. In this paper, using food sovereignty as a conceptual framework, we propose a quantitative methodology that allows analysis of the functioning of food systems at the international level. We present a database with 97 indicators distributed into six categories: 1) access to resources; 2) productive models; 3) commercialization; 4) food consumption and the right to food; 5) agrarian policies and civil society organization, and 6) gender. We also present the limitations found in developing the database as well as its potential applications for a wide variety of actors.Dr. Rivera-Ferre is a Ramon y Cajal Research Fellow from the Spanish Ministry of Economy (MINECO). MS. Adriana Ruiz-Almeida held a grant of the Mexican National Council of Science and Technology (CONACYT).Peer reviewe

A social–ecological analysis of the global agrifood system

Eradicating world hunger—the aim of Sustainable Development Goal 2 (SDG2)—requires a social–ecological approach to agrifood systems. However, previous work has mostly focused on one or the other. Here, we apply such a holistic approach to depicting the global food panorama through a quantitative multivariate assessment of 43 indicators of food sovereignty and 28 indicators of sociodemographics, social being, and environmental sustainability in 150 countries. The results identify 5 world regions and indicate the existence of an agrifood debt (i.e., disequilibria between regions in the natural resources consumed, the environmental impacts produced, and the social wellbeing attained by populations that play different roles within the globalized agrifood system). Three spotlights underpin this debt: 1) a severe contrast in diets and food security between regions, 2) a concern about the role that international agrifood trade is playing in regional food security, and 3) a mismatch between regional biocapacity and food security. Our results contribute to broadening the debate beyond food security from a social–ecological perspective, incorporating environmental and social dimensions.Peer reviewe

Development of a murine vertical transmission model for Toxoplasma gondii oocyst infection and studies on the efficacy of bumped kinase inhibitor (BKI)-1294 and the naphthoquinone buparvaquone against congenital toxoplasmosis

Objectives: Establishment of a mouse model for congenital toxoplasmosis based on oral infection with oocysts from Toxoplasma gondii ME49 and its application for investigating chemotherapeutic options against congenital toxoplasmosis. Methods: CD1 mice were mated, orally infected with 5, 25, 100, 500 or 2000 oocysts and monitored for clinical signs and survival of dams and pups until 4 weeks post partum. The parasite burden in infected mice was quantified by real-time PCR in lungs, brains and, in the case of surviving pups, also in eyes. Seroconversion was assessed by ELISA. T. gondii cysts in brain were identified by immunofluorescence. In a second experiment, pregnant CD1 mice challenged with 20 oocysts/mouse were treated with buparvaquone or the calcium-dependent protein kinase 1 inhibitor bumped kinase inhibitor (BKI)-1294 and the outcome of infection was analysed. Results: T. gondii DNA was detected in the brain of all infected animals, irrespective of the infection dose. Seroconversion occurred at 3 weeks post-infection. Most pups born to infected dams died within 1 week post partum, but a small fraction survived until the end of the experiment. T. gondii DNA was detected in the brain of all survivors and half of them exhibited ocular infection. Chemotherapy with both compounds led to dramatically increased numbers of surviving pups and reduced cerebral infection. Most efficient were treatments with BKI-1294, with 100% survivors and only 7% brain-positive pups. Conclusions: BKI-1294 and buparvaquone exert excellent activities against transplacental transmission in pregnant mice