Application of principal component analysis to identify pollen subtypes in Miconia (Melastomataceae)

Miconia Ruiz et Pav. es un género característico de regiones selváticas que en Argentina está representado por 10 especies. El objetivo de este trabajo fue la identificación de posibles subtipos polínicos en las especies argentinas de este género señalado como estenopalínico por estudios previos. Se midieron 60 granos de polen de cada una de las especies al microscopio óptico y se realizó un análisis de componentes principales y un árbol de recorrido mínimo, basados en una matríz de especies y variables morfométricas de los granos. Fueron seleccionados dos componentes principales que en conjunto explicaron el 77% de la variación total de los datos. La mayoría de las variables se correlacionaron con el componente 1. Seis especies se definieron en tres subtipos, restando cuatro que no pudieron ser incluidas en ninguno de ellos por presentar caracteres intermedios. Se concluyó que el análisis multivariado constituye una posible herramienta para ayudar a diferenciar subtipos polínicos dentro de géneros estenopalínicos.Miconia Ruiz et Pav. inhabits forest regions being represented in Argentina by 10 species. The aim of this study was to identify possible pollen subtypes in the Argentine species of Miconia. Previous studies found that the genus is stenopalynous. Pollen grains of each species were measured with an optical microscope and a PCA was conducted based on a matrix of species versus morphometric variables of pollen grains. Two components were selected because these explained together 77% of the total variation in the data. Most of the variables were correlated with component 1. Three pollen subtypes were defined in the genus, but four of the species could not be included in any of them because they presented intermediated characters. It was concluded that multivariate analysis is a possible tool that helps to differentiate pollen subtypes within stenopalynous genera.Fil: Ceballos, Sergio Javier. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, Maria E.. Fundación Miguel Lillo; ArgentinaFil: Slanis, Alberto C.. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Reyes, Nora J. F.. Fundación Miguel Lillo; Argentin

Pollen morphology of native and cultivated species of Handroanthus (Bignoniaceae) present in Argentina

Morfología polínica de las especies nativas y cultivadas de Handroanthus (Bignoniaceae) de la República Argentina. El objetivo del siguiente trabajo consiste en ampliar el conocimiento palinológico de las especies de Handroanthus (Bignoniaceae) presentes en Argentina e incorporar esta información al Atlas Polínico del NOA que se publica periódicamente on line (www.atlaspolinicodelnoa.com.ar). Se analizaron las siguientes especies: H. albus (Cham.) Mattos, H. chrysotrichus (Mart. ex DC.) Mattos, H. heptaphyllus (Vell.) Mattos, H. impetiginosus (Mart.ex DC.) Mattos, H. lapacho (K. Schum.) Mattos, H. ochraceus (Cham.) Mattos, además de la exótica H. pulcherrimus (Sandwith) S. Grose. El material fue procesado según las técnicas convencionales para acetólisis y polen natural, se tomaron fotos a nivel de microscopía óptica (MO) y microscopía electrónica de barrido (MEB). Los resultados muestran que los granos son medianos de 25 a 31,6 μm en polen natural y de 27,45 a 48 μm en polen acetolizado, suboblatos a subprolatos. Tricolporados (colporoidados) en H. albus, H. chrysotrichus, H. heptaphyllus, H. impetiginosus, H. lapacho y H. pulcherrimus, y 3-colporados (colporoidados), 3-hemisincolporados y loxocolporados en H. ochraceus. La exina es de 1,5 a 2 μm de espesor con la superficie reticulada heterobrocada

Pollen morphology of ornamental species from San Miguel de Tucumán (Tucumán, Argentina)

San Miguel de Tucumán posee vegetación ornamental de carácter exótico y autóctono distribuída en calles y plazas. Con el objeto de facilitar la identificación de los granos de polen presentes tanto en sedimentos melíferos como en muestreos aerobiológicos locales, el presente trabajo continúa la descripción de la morfología polínica de la flora ornamental de esta ciudad. Se analizaron 10 especies arbóreas y arbustivas: Brachychiton populneus (Schott & Endl.) R. Br. (Malvaceae); Caesalpinia gilliesii (Wall. ex Hook.) D. Dietr.(Fabaceae); Campsis radicans (L)Bureau (Bignoniaceae); Euphorbia milii Des Moul. (Euphorbiaceae); Hibiscus rosa-sinensis L.; H. rosa-sinensis L.var.schizopetalus Boulger, H. mutabilis L., (Malvaceae); Hydrangea macrophylla (Thunb.) Ser. (Hydrangeaceae); Jacaranda mimosifolia D. Don (Bignoniaceae) y Ligustrum lucidum W.T. Aiton (Oleaceae). Las muestras provienen de material fresco y fueron procesadas según las técnicas convencionales de acetólisis y polen natural. Las preparaciones microscópicas fueron incorporadas a la Palinoteca (PAL-TUC) de la Fundación Miguel Lillo (FML). Se tomaron fotos con MO y MEB. Las descripciones polínicas amplían estudios previos realizados por diversos autores excepto en Hydrangea macrophylla y Jacaranda mimosifolia, de los que no encontramos referencias sobre morfología polínica en trabajos anteriores. De las especies estudiadas Ligustrum lucidum ha sido registrado en muestreos aerobiológicos. Brachychiton populneus, Hibiscus rosa-sinensis, Hibiscus rosa-sinensis var. schizopetalus y Euphorbia milii se han encontrado en muestras melisopalinológicas

Satellite and ground atmospheric particulate matter detection over Tucuman city, Argentina, space-time distribution, climatic and seasonal variability

The analysis of atmospheric particles (aerosols) is of special interest due to their potential effects on human health and other applications. In this paper the climatic and seasonal effects on aerosols have been characterized in Tucumán city (26°50’ S, 65° 13’ W,450 masl),Argentina, for the 2006–2013 period. The atmospheric aerosols in Tucumán city result from both stationary and mobile sources such as: industrial activity of sugar cane and alcohol distilleries, paper industry, biomass burning (mainly sugarcane waste crop and grasslands), household waste burning and transport emissions. The peak of industrial activity is seasonal, coincident with the austral winter (July-August-September), when accumulation of particles in the lower atmosphere occurs. In this region, there are no studies like the present one that evaluate, using “in situ” equipment, the temporal variation of aerosols and its causes, by applying modern analytical techniques. A continuous volumetric and isokinetic sampler of Hirst type (Burkard), was used for atmospheric particle sampling, in weekly records between 2006 and 2013. The particle concentration (number of particles per cubic meter) showed an increasing trend in the studied period. The monthly variation of: the particle concentration; the aerosol optical thickness at a wavelength of 550 nm (AOD550) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard Aqua (NASA) satellite, and the AOD from different aerosol tracers (black and organic carbon, sea salt, sulfates, dust) obtained from the Modern-Era Retrospective Analysis for Research and Applications (MERRA-2), were also analyzed. The temporal variation in particle concentration was explained mostly by wind direction, while the corresponding variation for AOD550(MODIS) was explained by temperature and seasonality (as by-product of climatic variation and anthropogenic particle emission sources). The variation in the AOD550(MERRA-2) data series were explained by temperature, humidity, precipitation, and seasonality, with less effect of wind speed and direction. Particle concentration, AOD550(MODIS), and AOD550(MERRA-2) were highly variable. The cross-correlation between AOD550(MODIS) and AOD550(MERRA-2) time series was significantly positive at lag zero. Other contribution was the determination of the space-time distribution of aerosols on a monthly basis considering AOD550 MODIS (3 km × 3 km) data. The present study suggests that these variables are affected by temperature and wind dynamics driven by seasonal and high-order autoregressive non-linear processes.Fil: García, María E.. Laboratorio de Palinología; ArgentinaFil: Della Ceca, Lara Sofia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Micheletti, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Piacentini, Ruben Dario Narciso. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Ordano, Mariano Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Reyes, Nora J. F.. Fundación Miguel Lillo; ArgentinaFil: Buedo, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: González, Juan A.. Fundación Miguel Lillo; Argentin

Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae)

Antecedentes y Objetivos: La gran variabilidad de caracteres en Dioscorea dificultan la delimitación de las especies, por lo que estudios complementarios son necesarios para lograr su identificación. Dioscorea ayardei, especie endémica descrita recientemente de las Sierras de Calilegua (Jujuy, Argentina), se diferencia por la particularidad del androceo en sus flores estaminadas, la cual consiste en una estructura navicular con una sola antera en el centro y tres apéndices dendriformes erectos. El objetivo de este trabajo fue realizar un estudio conjunto de sus caracteres cromosómicos y palinológicos, que sumados a los morfológicos aporten información complementaria para su correcta delimitación. Métodos: El material estudiado fue identificado según los métodos clásicos en taxonomía y depositado en el Herbario LIL, de la Fundación Miguel Lillo. Para estudiar la meiosis se seleccionaron al azar botones florales jóvenes, que fueron fijados en Farmer durante 24 horas y conservados en alcohol etílico 70° a -4°C. La tinción de los cromosomas se realizó con hematoxilina propiónica al 2%. La fertilidad de los granos de polen se estimó mediante las técnicas de Mützing y DAPI. Para describir la morfología polínica, el material fue procesado según las técnicas convencionales de acetólisis y polen natural; se tomaron fotos con microscopía óptica (MO) y electrónica de barrido (MEB). Resultados clave: Dioscorea ayardei presentó un número gametofítico n=20II. El comportamiento meiótico fue generalmente regular. Las técnicas para estimar viabilidad y fertilidad del grano de polen revelaron un valor de 90-93% respectivamente. La morfología muestra un grano disulcado de tamaño pequeño (16-24 µm) a mediano (25-30 µm) con tectum microreticulado. Conclusiones: Se reafirma el número cromosómico básico para el género x=10. Dioscorea ayardei es un tetraploide con n=20, de comportamiento meiótico normal que concuerda con la viabilidad potencial del grano de polen. La ornamentación de la exina y el número cromosómico la relaciona con el clado Nuevo Mundo II.Background and Aims: The great variability of characters in Dioscorea makes it difficult to define the species, therefore additional studies are necessary to identify them. Dioscorea ayardei, a recently described endemic species from the Sierras de Calilegua (Jujuy, Argentina), differs by the particularity of the androecium of its staminate flowers which consists of a navicular structure with a single anther in the center and three erect dendriform appendages. The aim of this paper was to carry out an ensemble study of its chromosomal and palynological characters that, added to the morphological ones, provide complementary information for its correct delimitation. Methods: The studied material was identified according to the classic methods in taxonomy and deposited in the LIL Herbarium, of the Fundación Miguel Lillo. For study of meiosis, young flower buds were randomly selected, which were fixed in Farmer for 24 hours and preserved in 70° to -4°C ethyl alcohol. For chromosome staining, 2% propionic hematoxylin was used. Fertility of pollen grains was estimated using the Mützing and DAPI techniques. For the pollen morphology description the material was processed according to the conventional techniques of acetolysis and natural pollen; photographs were taken with light microscope (LM) and scanning electron microscope (SEM). Key results: Dioscorea ayardei presented a gametophytic number n=20II. Meiotic behavior was generally regular. The techniques to estimate viability and fertility of the pollen grain revealed a value of 90-93%, respectively. The morphology showed a small (16-24 µm) to medium (25-30 µm) sized disulcate grain with microreticulate tectum. Conclusions: The basic chromosome number for the genus x=10 is reaffirmed. Dioscorea ayardei is a tetraploid with n=20, with normal meiotic behavior consistent with the potential viability of the pollen grain. The exine ornamentation and chromosome number relates with the New World II clade

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity

Arboviral Etiologies of Acute Febrile Illnesses in Western South America, 2000–2007

Over recent decades, the variety and quantity of diseases caused by viruses transmitted to humans by mosquitoes and other arthropods (also known as arboviruses) have increased around the world. One difficulty in studying these diseases is the fact that the symptoms are often non-descript, with patients reporting such symptoms as low-grade fever and headache. Our goal in this study was to use laboratory tests to determine the causes of such non-descript illnesses in sites in four countries in South America, focusing on arboviruses. We established a surveillance network in 13 locations in Ecuador, Peru, Bolivia, and Paraguay, where patient samples were collected and then sent to a central laboratory for testing. Between May 2000 and December 2007, blood serum samples were collected from more than 20,000 participants with fever, and recent arbovirus infection was detected for nearly one third of them. The most common viruses were dengue viruses (genera Flavivirus). We also detected infection by viruses from other genera, including Alphavirus and Orthobunyavirus. This data is important for understanding how such viruses might emerge as significant human pathogens

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks