Epilithic diatoms in the Upper Laja River Basin, Guanajuato, Mexico

This study investigates the epilithic diatoms from the Dolores and Laja Rivers, located within the Upper Laja River Basin, Guanajuato, Mexico. The samples were collected during the cold-dry (January) and rainy (October) seasons of 2011. One-hundred seventy three infrageneric taxa were identified, 7 of which are new records for Mexico: Fallacia monoculata, Hantzschia abundans, Navigiolum uruguayense, Neidium bisulcatum, Nitzschia solita, Planothidium incuriatum and Sellaphora bacilloides; it is worth mentioning that Navigiolum is a new record at the genus level. Furthermore, 3 species are new records for the state of Guanajuato: Gomphonema laticollum, G. subclavatum and Gomphosphenia lingulatiformis. Teratological forms of 6 species were also found in the sampling sites with higher nutrient concentrations, with relative abundances varying from 0.8 to 8.3%

Epilithic diatom communities of selected streams from the Lerma-Chapala Basin, Central Mexico, with the description of two new species

The Lerma-Chapala Basin, in Central Mexico, is geologically heterogeneous, climatically diverse and boasts high biodiversity, lying within two Biodiversity Hotspots, namely Mesoamerica and the Madrean Pine–Oak Woodlands. Epilithon and water samples were collected in the basin from 14 sampling sites three times each, two sampling campaigns during the rainy season and one in the dry season. A total of 274 infrageneric taxa in 48 genera were recorded. The taxonomic composition observed was dominated by taxa from the genera Nitzschia, Gomphonema, Pinnularia, Navicula, Sellaphora and Eunotia. About a third of the taxa found could not be identified to the species level. From those unidentified morphodemes, two are described as new species, namely Brachysira altepetlensis and Sellaphora queretana. Furthermore, Eolimna rhombica is transferred to Sellaphora. Canonical Correspondence Analysis (CCA) revealed that specific conductivity and pH were the main environmental factors driving the community composition observed. Three groups of samples were identified after the CCA: 1) characterized by acidic waters and low conductivity; 2) with circumneutral waters, low specific conductivity and high temperature and phosphorous concentrations; and 3) characterized by circumneutral waters, high conductivity and low nitrogen concentrations. The indicator value method (IndVal), based on the relative abundance and relative frequency of the most abundant taxa was calculated based on the groups observed in the CCA, identifying the characteristic taxa for each of the three groups

Integrative taxonomic description of two new species of the Cocconeis placentula group (Bacillariophyceae) from Korea based on unialgal strains

Cocconeis coreana and C. sijunghoensis are described as new based on micromorphological and molecular data C. coreana is represented by five unialgal cultures from four different freshwater bodies, two from North Korea and three from South Korea. C. sijunghoensis is represented by two unialgal cultures from a brackish water body in North Korea. Except for one, all of the strains auxosporulated and showed an almost quadrupling of size in length and width. Morphologically, these species with their two different elliptical valves belong to the Cocconeis placentula group. The raphe valve has striae with uniseriate areolae continuing across a pronounced submarginal hyaline rim to the edge of the valve. The sternum valve has uniseriate dash-like areolae continuously from the valve face until the valve edge. Micromorphologically, these species possess two different open valvocopulae: only the raphe valvocopula has fimbriae; the sternum valvocopula has none. Based on p-distances of currently available DNA sequence data, i.e., rbcL and 18SV4, both species are pronouncedly different from the epitype strain of C. placentula, with C. coreana closest to the published molecular data of the strain UTEX FD23 named C. placentula from Iowa, USA, while C. sijunghoensis is closest but not the same as the publ is hed molecular data of strain D36_012, the epitype strain of C. placentula from Berlin, Germany. Based on scanning elect ron microscope observations, differentiating features are discussed concerning valvocopula fimbriae, central area, areolation of the sternum valve and on the raphe valve especially between the submarginal hyaline rim and edge

Resistencia química del hormigón. VI.-Acción del agua de mar artificial que fluye a través de un lecho de mortero fabricado con un cemento portland de alta resistencia inicial

Not availableEn el presente trabajo se estudia el comportamiento de un cemento portland de alta resistencia inicial (P-550-ARI), objeto de otras publicaciones, cuando se somete a la acción del agua de mar artificial (ASTM D 1141-75), que atraviesa un lecho de mortero (1:3) hecho con el mencionado cemento, determinando, en esta etapa previa, la variación de la concentración de los iones Ca (II), Mg (II) y SO4 (II) tanto del agua de mar artificial como de la fracción enriquecida (pasta de cemento hidratado-atacado) extraída del lecho y, además, Cl (I) del agua de mar artificial

Resistencia química del hormigón. VII.-Acción del agua de mar artificial que fluye a través de un lecho de mortero fabricado con un cemento portland resistente al yeso

Not availableEn el presente trabajo se estudia el comportamiento de un cemento portland resistente al yeso (P-450-Y), objeto de otras publicaciones, cuando se somete a la acción del agua de mar artificial (ASTM D 1141-75) que atraviesa un lecho de mortero (1:3) fabricado con el mencionado cemento, determinando, en esta etapa previa, la variación de la concentración de los iones Ca (II), Mg (II) y SO4 (II) tanto del agua de mar artificial como de la fracción enriquecida (cemento hidratado-atacado) extraída del lecho y, además, la del ion Cl (I) en el agua de mar artificial

Diatom DNA metabarcoding for ecological assessment: Comparison among bioinformatics pipelines used in six European countries reveals the need for standardization

Ecological assessment of lakes and rivers using benthic diatom assemblages currently requires considerable taxonomic expertise to identify species using light microscopy. This traditional approach is also time-consuming. Diatom metabarcoding is a promising alternative and there is increasing interest in using this approach for routine assessment. However, until now, analysis protocols for diatom metabarcoding have been developed and optimised by research groups working in isolation. The diversity of existing bioinformatics methods highlights the need for an assessment of the performance and comparability of results of different methods. The aim of this study was to test the correspondence of outputs from six bioinformatics pipelines currently in use for diatom metabarcoding in different European countries. Raw sequence data from 29 biofilm samples were treated by each of the bioinformatics pipelines, five of them using the same curated reference database. The outputs of the pipelines were compared in terms of sequence unit assemblages, taxonomic assignment, biotic index score and ecological assessment outcomes. The three last components were also compared to outputs from traditional light microscopy, which is currently accepted for ecological assessment of phytobenthos, as required by the Water Framework Directive. We also tested the performance of the pipelines on the two DNA markers (rbcL and 185-V4) that are currently used by the working groups participating in this study. The sequence unit assemblages produced by different pipelines showed significant differences in terms of assigned and unassigned read numbers and sequence unit numbers. When comparing the taxonomic assignments at genus and species level, correspondence of the taxonomic assemblages between pipelines was weak. Most discrepancies were linked to differential detection or quantification of taxa, despite the use of the same reference database. Subsequent calculation of biotic index scores also showed significant differences between approaches, which were reflected in the final ecological assessment. Use of the rbcL marker always resulted in better correlation among molecular datasets and also in results closer to these generated using traditional microscopy. This study shows that decisions made in pipeline design have implications for the dataset's structure and the taxonomic assemblage, which in turn may affect biotic index calculation and ecological assessment. There is a need to define best-practice bioinformatics parameters in order to ensure the best representation of diatom assemblages. Only the use of similar parameters will ensure the compatibility of data from different working groups. The future of diatom metabarcoding for ecological assessment may also lie in the development of new metrics using, for example, presence/absence instead of relative abundance data. (C) 2020 The Authors. Published by Elsevier B.V

Anti-IL-6 Receptor Tocilizumab in Refractory Graves? Orbitopathy: National Multicenter Observational Study of 48 Patients

Graves’ orbitopathy (GO) is the most common extrathyroidal manifestation of Graves’ disease (GD). Our aim was to assess the e cacy and safety of Tocilizumab (TCZ) in GO refractory to conventional therapy. This was an open-label multicenter study of glucocorticoid-resistant GO treated with TCZ. The main outcomes were the best-corrected visual acuity (BVCA), Clinical Activity Score (CAS) and intraocular pressure (IOP). These outcome variables were assessed at baseline, 1st, 3rd, 6th and 12th month after TCZ therapy onset. The severity of GO was assessed according to the European Group on Graves’ Orbitopathy (EUGOGO). We studied 48 (38 women and 10 men) patients (95 eyes); mean age standard deviation 51 11.8 years. Before TCZ and besides oral glucocorticoids, they had received IV methylprednisolone (n = 43), or selenium (n = 11). GO disease was moderate (n =29) or severe (n = 19) and dysthyroid optic neuropathy (DON) (n = 7). TCZ was used in monotherapy (n = 45) or combined (n = 3) at a dose of 8 mg/kg IV every four weeks (n = 43) or 162 mg/s.c. every week (n = 5). TCZ yielded a significant improvement in all of the main outcomes at the 1st month that was maintained at one year. Comparing the baseline with data at 1 year all of the variables improved; BCVA (0.78 0.25 vs. 0.9 0.16; p = 0.0001), CAS (4.64 1.5 vs. 1.05 1.27; p = 0.0001) and intraocular pressure (IOP) (19.05 4.1 vs. 16.73 3.4 mmHg; p = 0.007). After a mean follow-up of 16.1 2.1 months, low disease activity (CAS 3), was achieved in 88 eyes (92.6%) and TCZ was withdrawn in 29 cases due to low disease activity (n = 25) or ine cacy (n = 4). No serious adverse events were observed. In conclusion, TCZ is a useful and safe therapeutic option in refractory GO treatment.This work was also partially supported by RETICS Programs, RD08/0075 (RIER) and RD12/0009/0013 from “Instituto de Salud Carlos III” (ISCIII) (Spain)

Ein integrativer Ansatz zur Analyse der Vielfalt epilithischer Diatomeen in tropischen Bächen des Lerma-Chapala Beckens, Zentralmexiko

The study and application of diatoms as biological indicators in Mexico is infrequent, despite the multiple advantages offered by these organisms in the assessment and monitoring of freshwaters. In the few diatom studies of Mexican freshwaters, there seems to be low species diversity and an inherent cosmopolitanism of taxa, contrary to what would have been expected of a megadiverse country. This was mainly because of 1) force-fitting identifications based on monographs from temperate regions and 2) the lone use of light microscopy for identifications, which not always differentiates between closely related species. In order to better assess the diatom diversity of the country and to set an identification baseline for future studies using diatoms as biological indicators, this dissertation presents an integrative approach to epilithic diatom diversity analysis in tropical streams from the Lerma-Chapala Basin, Central Mexico. This study is based on a representative sampling of diatoms from small, mostly undisturbed, mountain streams from the north and east sections of the basin, as well as samples from the west of the basin, which include the heavily polluted Lerma River and some of its major tributaries. Samples were collected during the most contrasting periods of the year, the rainy and dry seasons. In the first part of this work, the diatom samples of the small mountain streams from the north and east sections of the basin were cultivated for morphological, ecological, molecular and phylogenetic analysis. The morphological evaluation resulted in the largest diatom diversity reported for Mexico to date, 274 infrageneric taxa, including the description of two new species, Brachysira altepetlensis and Sellaphora queretana. The ecological analysis revealed that the community composition observed was mainly driven by the ionic composition of the water, with indicator taxa identified for the varying conditions in pH, conductivity and nutrients. Under the premise that diatom identifications at species level in environmental DNA (eDNA) metabarcoding studies rely heavily on the completeness of reference databases, a regional morphological and molecular taxonomic reference library was assembled by diatom cultivation. The eDNA metabarcoding approach tested here, which integrates molecular and tree-based phylogenetic methods, revealed a larger diversity than the one recorded by morphological analysis. One quarter of the taxa assigned to species level in the eDNA metabarcoding approach was attributable to the herein assembled taxonomic reference library, supporting the aforementioned premise. The use of a regional sequence reference database is to increase the identification success, particularly in poorly studied regions such as the tropics. By comparing the diversity retrieved by morphology and eDNA metabarcoding, it was found that neither morphology nor eDNA metabarcoding were a better method than the other in catching the entire diversity; they were rather complementary. The cultivation of diatoms revealed a concealed diversity not detected by morphology or eDNA metabarcoding, suggesting cultivation as a further method to unravel species diversity from environmental samples. The relative abundances recorded by morphology (diatom valves) and eDNA metabarcoding (sequence reads) showed large disparities, even after the application of correction factors. This suggests that further methodological improvements are needed in order to establish eDNA metabarcoding as a standard method for water analysis. Furthermore, the results presented here support the retrieval of DNA reference barcodes from High-Throughput Sequencing data. In the second part of this study all the samples, including those from the Lerma River and its major tributaries, were studied by microscopy (light and scanning electron microscopy) in order to prepare a detailed illustrated identification guide. The analysis resulted in 307 infrageneric taxa, with the description of ten new species, belonging to Cocconeis, Craticula, Gomphonema and Sellaphora. This identification guide represents the baseline for diatom identification in future monitoring studies and programs in the region. In the third part of this dissertation, the taxonomy and systematics of the Planothidium lanceolatum/P. frequentissimum species complexes were explored by morphological and molecular data obtained from clonal cultures and from sequences deposited at the INSDC databases. Besides Mexico, the analyzed strains came from France, Germany, the Faroe Islands, Korea, Lake Baikal in Russia, New Zealand and the USA. The analysis resulted in the recognition of eight species, with three described as new to science. Both molecular and morphology-based phylogenetic analyses led to postulate the sinus and cavum as important stable taxonomic characters. The fine-grained taxonomy applied in this study allowed to revisit the distribution of Planothidium frequentissimum and P. lanceolatum, taxa previously considered to be cosmopolitan. Morphological and molecular based approaches for the study of diversity are often seen as antagonistic, with morphology seen as methodologically outdated and time consuming while molecular methods are seen as a means of choice. However, the results of this study rather underline complementarity of both methods. The integrative approach to the study of diatoms presented in this dissertation allowed an improved assessment of the diversity of epilithic diatoms from the Lerma-Chapala Basin, Central Mexico, setting the baseline for future monitoring studies in this biodiversity rich but threatened region of Mexico.Untersuchungen zu Anwendungen von Diatomeen als Bioindikatoren sind trotz der vielfältigen Vorteile, die diese Organismen bei der Beobachtung und Begutachtung von Süßwasser bieten, in Mexiko selten. In den wenigen Studien zu Mexikos Süßwassersystemen wird von einer geringen Artenvielfalt und überwiegend kosmopolitischen Taxa ausgegangen. Dies rührt vor allem aus (1) der Identifikation der Taxa ausschließlich nach Monographien der gemäßigten Zonen und (2) der alleinigen Nutzung der Lichtmikroskopie zur Identifikation, die nicht immer eine Unterscheidung nah verwandter Arten erlaubt. Zur genaueren Untersuchung der Diatomeenvielfalt des Landes und zur Schaffung einer Grundlage für zukünftige Arbeiten, die Diatomeen als Bioindikatoren behandeln, wird mit dieser Dissertation ein integrativer Ansatz zur Analyse der Vielfalt epilithischer Diatomeen in tropischen Bächen des Lerma-Chapala Beckens in Zentralmexiko vorgelegt. In dieser Arbeit wurden repräsentative Proben von Diatomeen aus kleinen, weitgehend ungestörten Bergbächen aus den nördlichen und östlichen Teilen sowie dem westlichen Teil des Beckens verwendet. Diese Region schließt auch den stark verschmutzten Fluss Lerma und einige seiner wichtigsten Zuflüsse ein. Es wurden Proben während der beiden kontrastreichsten Saisons des Jahres gesammelt, der Trocken- und der Regenzeit. Im ersten Teil dieser Arbeit wurden die Diatomeen aus den Proben der kleinen Bergbäche aus dem Nord- und Ostteil des Beckens für morphologische, ökologische, molekulare und phylogenetische Analysen kultiviert. Die morphologischen Untersuchungen ergaben die größte, bisher dokumentierte Vielfalt an beschriebenen Diatomeenarten Mexikos: 274 infragenerische Arten, darunter die Beschreibung zweier neuer Arten, Brachysira altepetlensis und Sellaphora queretana. Die ökologische Untersuchung zeigte, dass die beobachtete Zusammensetzung der Gemeinschaft vor allem durch die Ionenkonzentration des Wassers bestimmt wird. In Abhängigkeit der weiteren Parameter pH, Leitfähigkeit und Nährstoffgehalt konnten relevante Indikatorarten identifiziert und zugeordnet werden. In dem Wissen, dass die Identifikation von Diatomeen auf Artenebene mittels Environmental DNA (eDNA) Metabarcoding stark von der Vollständigkeit von Referenzdatenbanken abhängt, wurde eine regionale morphologische und molekulartaxonomische Referenzbibliothek mittels Diatomeenkultivierung erstellt. Der hier getestete eDNA-Metabarcoding-Ansatz, der molekulare und phylogenetische Stammbaum-Methoden zur Taxazuordnung einsetzt, offenbarte eine größere Vielfalt als die morphologischen Untersuchungen. Ein Viertel der Taxa, die durch die eDNA-Metabarcoding-Analyse auf Artenebene zugeordnet wurden, konnte nur auf Grundlage der eigens erstellten Referenzbibliothek zugeordnet werden. Der Nutzen einer regionalen Sequenzdatenbank als Referenz liegt in der Steigerung des Identifikationserfolges, speziell in weniger gut untersuchten Regionen wie den Tropen. Im Vergleich der gefundenen Artenvielfalten durch morphologische Untersuchungen einerseits und eDNA-Metabarcoding-Analysen andererseits, zeigte sich, dass keine der beiden Methoden der anderen überlegen ist; die Methoden sind vielmehr als komplementär zu betrachten. Die Kultivierung und Analyse zusätzlicher Diatomeen brachte noch weitere Arten zum Vorschein, die durch reine Evaluierung der Umweltproben nicht detektiert werden konnten. Dies unterstreicht die enorme Bedeutung der Diatomeenkultivierung als ergänzende Methode zur Erschließung der Artenvielfalt. Die relativen Häufigkeiten, die durch die morphologische Untersuchung (Diatomeenschalen) oder die eDNA-Metabarcoding-Analyse (Sequenzen) verzeichnet werden konnten, zeigten im Vergleich der beiden Ansätze große Unterschiede, sogar nach Anwendung von Korrekturfaktoren. Dies weist darauf hin, dass weitere methodische Verbesserungen notwendig sind um eDNA-Metabarcoding als Routineverfahren zur Wasseranalyse einzusetzen. Desweiteren zeigen die Ergebnisse, dass DNA-Barcodes für die Referenzbibliothek durch Hochdurchsatzsequenzierung (HTS) gewonnen werden können. Im zweiten Teil der Arbeit wurden alle Proben, auch diejenigen des Flusses Lerma und seinen größeren Zuflüssen durch Mikroskopie (Licht - und Rasterelektronenmikroskopie) untersucht, um detaillierte und bebilderte Bestimmungsreferenzen zu erhalten. Es konnten 307 infragenerische Taxa identifiziert werden, wobei zehn neue Arten beschrieben werden konnten, die zu den Gattungen Cocconeis, Craticula, Gomphonema und Sellaphora gehören. Diese Identifikationsdaten dienen als Grundlage für zukünftige Forschungsarbeiten in der Region. Im dritten Teil der Dissertation wurde die Taxonomie und Systematik des Artenkomplexes Planothidium lanceolatum / P. frequentissimum mittels morphologischer und molekularer Daten, die aus Klonkulturen und aus INSDC-Sequenzen gewonnen wurden, untersucht. Neben Mexiko stammen die untersuchten Kulturen aus Frankreich, Deutschland, den Färöer Inseln, Korea, dem russischen Baikalsee, Neuseeland und den USA. Es konnten acht Arten identifiziert werden, darunter drei für die Wissenschaft neue. Sowohl die molekularen als auch die morphologisch-phylogenetischen Untersuchungen führten zur Erkenntnis, dass Sinus und Cavum wichtige stabile, taxonomische Merkmale darstellen. Der detaillierte und integrative Ansatz der Taxonomie, der in dieser Arbeit angewendet wurde, erlaubte eine Neubewertung der Zuordnung der Taxa Planothidium frequentissimum und P. lanceolatum, die bis dato als kosmopolitisch eingestuft wurden. Morphologische und molekularbasierte Ansätze zur Untersuchung der Artenvielfalt werden oft als antagonistisch behandelt, wobei die morphologische Analyse als methodisch überholt und zeitaufwändig gilt und die molekulare Methode als Mittel der Wahl erachtet wird. Die Ergebnisse dieser Arbeit zeigen jedoch gerade die Komplementarität beider Ansätze auf. Der integrative Ansatz zur Untersuchung von Diatomeen, der in dieser Dissertation vorgelegt wird, führt zu einer besseren Beschreibung der Artenvielfalt epilithischer Diatomeen des Lerma-Chapala Beckens in Zentralmexiko. Es wurde somit die Grundlage für zukünftige Forschungsarbeiten in dieser artenreichen, aber gefährdeten Region Mexikos geschaffen

Tabulating and Visualizing Street Name Data in the U.S. and Europe

This paper introduces a new web app to visualize the spatial distribution of street names and download the underlying data. First, we motivate the relevance of street-name data for researchers in social sciences. Second, we describe the data sources employed as well as the data cleaning process. Third, we present a web search app that allows to spatially visualize and download street-name data for the US and a large part of Europe

Propuesta de un plan de seguridad Industrial para reducir los accidentes laborales en la empresa Gálvez S.A.C Lima 2019

Este trabajo de investigación se desarrolló en las instalaciones de la empresa Gálvez SAC., la cual está enfocada en la fabricación de cocinas semi industriales, desde hace 9 años. Este estudio se llevó a cabo durante el último trimestre del presente año, se planteó como objetivo general, determinar como el Plan de Seguridad Industrial va a reducir los accidentes laborales en la empresa Gálvez S.A.C. Para tal fin, el grupo de investigación evaluó la situación actual en la que se encontraba la empresa en temas de seguridad industrial, deduciendo así los riesgos laborales a los que se expone el trabajador. Con la línea base establecida, se elabora el plan de seguridad para su posterior implementación y evaluación de las mejoras que se propuso. Este proyecto de investigación es de tipo cuantitativa, se encuentra dentro de la metodología de estudio aplicada experimental, debido a que se realizó la manipulación de variables independientes. Sigue los lineamientos del diseño Pre – experimental, aplicando una pre y post prueba al grupo de control. Se tiene como población al personal administrativo, área de taller y almacén, la muestra es por conveniencia. Para la recolección de datos, es prescindible la observación (no estructurada) (lista de cotejo), de campo, el análisis del registro anecdótico del taller, así como, la matriz IPER y otras propuestas en la normativa. Por último, con los resultados obtenidos de la propuesta de un Plan de Seguridad Industrial se pudo demostrar la reducción de los accidentes laborales en la empresa Gálvez SAC. Es así que, a medida que esta propuesta se mantenga vigente y se continúe aplicando el Plan de Seguridad Industrial se va a reducir la accidentabilidad laboral en la empresa