Assessing non–parametric estimators of species richness. A case study with birds in green areas of the city of Puebla, Mexico

Nuestro objetivo fue evaluar el desempeño de estimadores no paramétricos de la riqueza de especies con datos reales. Durante la temporada de cría de 2003 censamos las comunidades de aves en dos áreas verdes de la ciudad de Puebla (México), y obtuvimos las corres¬pondientes curvas de rarefacción, que fueron ajustadas a dos funciones de acumulación de especies no asintóticas y siete asintóticas. Según criterios de la teoría de la información, la función de acumulación de Weibull o la Beta–P fueron las que mejor describieron estas curvas de acumulación, y asumimos que sus asíntotas estimaron la riqueza real en los dos sitios. Después evaluamos el sesgo, la precisión y la exactitud de cinco estimadores no paramétricos de la riqueza de especies (ICE, Chao 2, Jackknife 1, Jackknife 2 y Bootstrap) para esfuerzos de muestreo crecientes (1–53 unidades de censo). Todos los estimadores no paramétricos aquí evaluados subestimaron la riqueza asintótica la mayor parte del tiempo, en especial en una de las comunidades. Sin embargo, tras combinar los datos de los dos sitios, sólo ICE, Jackknife 1 y Jackknife 2 mostraron sesgos menores al 10% con algún esfuerzo de muestreo, aunque únicamente Jackknife 1 tuvo una exactitud global alta (error medio relativo al cuadradox100 &lt; 5%), incluso con esfuerzos de muestreo bajos (cerca del 20% del total de las unidades de censo). En conclusión, proponemos que el estimador no paramétrico Jackknife 1 puede usarse como un límite inferior de la riqueza de especies de aves en áreas urbanas similares a las de nuestro estudio. Palabras clave: Exactitud, Sesgo, Biodiversidad, Aves, Inventarios, Jackknife, Precisión, Urbanización.Nuestro objetivo fue evaluar el desempeño de estimadores no paramétricos de la riqueza de especies con datos reales. Durante la temporada de cría de 2003 censamos las comunidades de aves en dos áreas verdes de la ciudad de Puebla (México), y obtuvimos las corres¬pondientes curvas de rarefacción, que fueron ajustadas a dos funciones de acumulación de especies no asintóticas y siete asintóticas. Según criterios de la teoría de la información, la función de acumulación de Weibull o la Beta–P fueron las que mejor describieron estas curvas de acumulación, y asumimos que sus asíntotas estimaron la riqueza real en los dos sitios. Después evaluamos el sesgo, la precisión y la exactitud de cinco estimadores no paramétricos de la riqueza de especies (ICE, Chao 2, Jackknife 1, Jackknife 2 y Bootstrap) para esfuerzos de muestreo crecientes (1–53 unidades de censo). Todos los estimadores no paramétricos aquí evaluados subestimaron la riqueza asintótica la mayor parte del tiempo, en especial en una de las comunidades. Sin embargo, tras combinar los datos de los dos sitios, sólo ICE, Jackknife 1 y Jackknife 2 mostraron sesgos menores al 10% con algún esfuerzo de muestreo, aunque únicamente Jackknife 1 tuvo una exactitud global alta (error medio relativo al cuadradox100 &lt; 5%), incluso con esfuerzos de muestreo bajos (cerca del 20% del total de las unidades de censo). En conclusión, proponemos que el estimador no paramétrico Jackknife 1 puede usarse como un límite inferior de la riqueza de especies de aves en áreas urbanas similares a las de nuestro estudio. Palabras clave: Exactitud, Sesgo, Biodiversidad, Aves, Inventarios, Jackknife, Precisión, Urbanización.Our objective was to evaluate the performance of non–parametric estimators of spe¬cies richness with real data. During the 2003 breeding season, bird communities were sampled in two green areas in the city of Puebla (Mexico), and the corresponding sample–based rarefaction curves were obtained. Mean data were adjusted to two non–asymptotic and seven asymptotic accumulation functions, and the best model was selected by means of reliability criteria in information theory. The cumulative Weibull and the Beta–P functions were the best–fit models. Bias, precision and accuracy of five non–parametric estimators of species richness (ICE, Chao2, Jackknife 1, Jackknife 2, and Bootstrap) were then assessed for increasing sampling efforts (1–53 sampling units) against the asymptote of the selected accumulation functions. All the non–parametric estimators here evaluated underestimated true richness most of the time, specially in one of the sites. However, after combining data from the two assemblages, only ICE, and Jackknife 1 and 2 exhibited bias below 10% with different sampling efforts, and only Jackknife 1 was globally accurate (scaled mean squared errorx100< 5%, even with low sampling efforts, ca. 20% of the total). Therefore, we propose using the Jackknife 1 non–parametric estimator as a lower limit to measure bird species richness in urban sites similar to those in the present study. Key words: Accuracy, Bias, Biodiversity, Birds, Inventories, Jackknife, Precision, Urbanization

Phosphate Fertilization and Mycorrhizal Inoculation Increase Corn Leaf and Grain Nutrient Contents

The agricultural use of arbuscular mycorrhizal fungi, such as Rhizoglomus intraradices, can increase the efficiency of phosphate fertilization for the benefit of the corn plant and grain nutrition. In this study, a field experiment was conducted in an area of Selvíria/MS, Brazil, in the years 2019 and 2020, to verify the effects of reduced doses of phosphorus combined with the inoculation of corn seed with R. intraradices on corn plant growth and grain nutrient contents. The experiment was laid in a randomized block design in subdivided plots with four repetitions and twenty treatments resulting from combining five doses of P2O5 (0%, 25%, 50%, 75%, and 100% of the recommended dose) with four doses (0, 60, 120, and 180 g ha1) of an inoculant containing R. intraradices. Leaf and kernel macro- and micronutrient contents were evaluated. The foliar P content in 2020 was a function of the interaction between phosphate fertilization and AMF inoculation, with the highest leaf P content observed at the 100% of P2O5 combined with AMF inoculation between 120 and 140 g ha1. In the grains Mg content, an interaction was observed between the two factors in 2020 and the response surface, showing that the highest Mg content was obtained when maximum doses of P2O5 and maximum doses of inoculant were combined. A response surface showed that, in 2020, the highest leaf Zn content occurred when 35–55% P2O5 is applied with no inoculation and when P2O5 is limited to 20–30%, and there is inoculation with doses between 90 and 150 g ha1. Phosphate fertilization increased foliar K (2019) and Mg (2020) contents, with maximum points at doses of 76.57% and 88.80%, respectivelyinfo:eu-repo/semantics/publishedVersio

SEROPREVALENCE OF TOXOPLASMA GONDII IN FREE-RANGE LOCAL BIRDS IN SUMEL DISTRICT, DUHOK PROVINCE, IRAQ

In the present study, Direct Latex Agglutination Test (DLAT), Modified Agglutination Test (MAT) and enzyme-linked immunosorbent assay (ELISA) were used to detect the immune responses to Toxoplasma gondii (T. gondii) among free-range local birds (chicken, turkey, geese and ducks) in Sumel District of Duhok province, Iraq. The data revealed the overall seropositive rates of 62.2%, 33.3% and 21.1% by DLAT, MAT and ELISA, respectively. Non-significant differences were found between the prevalence rates among the tested birds indicating that all birds’ species to be susceptible for infection. The highest antibodies titers in response to T. gondii were found in chicken sera which was significantly higher (p < 0.05) than that in ducks. The data indicated that free-range local birds could be considered as important sources of toxoplasmosis for the locals in Duhok area. Preventative measurements should be taken to contain the further prevalence of the disease among the locals, namely pregnant women

MicroRNA signature from extracellular vesicles of HCV/HIV co-infected individuals differs from HCV mono-infected

Hepatitis C virus (HCV) coinfection with human immunodeficiency virus (HIV) has a detrimental impact on disease progression. Increasing evidence points to extracellular vesicles (EVs) as important players of the host-viral cross-talk. The microRNAs (miRNAs), as essential components of EVs cargo, are key regulators of normal cellular processes and also promote viral replication, viral pathogenesis, and disease progression. We aimed to characterize the plasma-derived EVs miRNA signature of chronic HCV infected and HIV coinfected patients to unravel the molecular mechanisms of coinfection. EVs were purified and characterized from 50 plasma samples (21 HCV mono- and 29 HCV/HIV co-infected). EV-derived small RNAs were isolated and analyzed by massive sequencing. Known and de novo miRNAs were identified with miRDeep2. Significant differentially expressed (SDE) miRNA identification was performed with generalized linear models and their putative dysregulated biological pathways were evaluated. Study groups were similar for most clinical and epidemiological characteristics. No differences were observed in EVs size or concentration between groups. Therefore, HCV/HIV co-infection condition did not affect the concentration or size of EVs but produced a disturbance in plasma-derived EVs miRNA cargo. Thus, a total of 149 miRNAs were identified (143 known and 6 de novo) leading to 37 SDE miRNAs of which 15 were upregulated and 22 downregulated in HCV/HIV co-infected patients. SDE miRNAs regulate genes involved in inflammation, fibrosis, and cancer, modulating different biological pathways related to HCV and HIV pathogenesis. These findings may help to develop new generation biomarkers and treatment strategies, in addition to elucidate the mechanisms underlying virus-host interaction. KEY MESSAGES: HCV and HCV/HIV displayed similar plasma-EV size and concentration. EVs- derived miRNA profile was characterized by NGS. 37 SDE miRNAs between HCV and HCV/HIV were observed. SDE miRNAs regulate genes involved in inflammation, fibrosis and cancer.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been supported by grants from (1) Institute of Health Carlos III, Spain [PI18CIII/00020/ to AFR], (2) PID2021–126781OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, (3) The SPANISH AIDS Research Network RD16CIII/0002/0002 - ISCIII – FEDER, (4) Centro de Investigación en Red en Enfermedades Infecciosas (CIBERINFEC) CB21/13/00044, (5) the National Agency for Scientific and Technology Promotion (ANPCyT) (PICT 2017 Nº713), and (6) the National Research Council (CONICET, PIP 2021-2023). V.C. received funding form the Asociación Universitaria Iberoamericana de Postgrado (AUIP) for the Academic Mobility Scholarship Program. P.V., E.D.M., and M.V.P. are members of the CONICET-Research Career Program. V.C. is a fellow from ANPCyT. The funder’s had no role in the study design, data collection and analysis, decision to publish, or the preparation of the manuscript.S

Source Coding and Speech Compression

International Telemetering Conference Proceedings / November 14-16, 1978 / Hyatt House Hotel, Los Angeles, CaliforniaAn overview of recent applications of source coding theory and techniques to Linear Predictive Coded Coded speech compression systems is presented. Several distortion measures proposed for use in speech compression systems are described and compared. These distortion measures are then combined with an algorithm for computing "optimum" (minimum distortion) vector quantizers to obtain optimum quantizers for reflection coefficient vectors in Linear Predictive Coded speech systems. The quality of the system is evaluated via the speech distortion measures and listening to demonstration tapes. Some implications for speech compression theory and practice are discussed.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection