The influence of biological rhythms on host–parasite interactions

Biological rhythms, from circadian control of cellular processes to annual cycles in life history, are a main structural element of biology. Biological rhythms are considered adaptive because they enable organisms to partition activities to cope with, and take advantage of, predictable fluctuations in environmental conditions. A flourishing area of immunology is uncovering rhythms in the immune system of animals, including humans. Given the temporal structure of immunity, and rhythms in parasite activity and disease incidence, we propose that the intersection of chronobiology, disease ecology, and evolutionary biology holds the key to understanding host–parasite interactions. Here, we review host–parasite interactions while explicitly considering biological rhythms, and propose that rhythms: influence within-host infection dynamics and transmission between hosts, might account for diel and annual periodicity in host–parasite systems, and can lead to a host–parasite arms race in the temporal domain

Nonreactive solute transport in soil columns: classical and fractional-calculus modeling

Vertical nonreactive solute transport data collected in three laboratory soil columns (made out of sediment samples from the Pampean aquifer located southeast of the Buenos Aires province) are contrasted with the explicit solutions of two model 1D linear PDEs: the classical advection–dispersion equation (ADE), and a fractional advection–dispersion equation (FADE) which has proven to be a useful modeling tool for highly inhomogeneous media exhibiting nontrivial scaling laws. Whereas two of the samples turn out to be quite homogeneous (thus requiring a fractional-derivative order γ → 2), the third one is best described by a FADE with fractional-derivative order γ = 1.68. This example illustrates the FADE’s ability to reveal self-similar geometric structures inside the sample.Fil: Benavente, Micaela Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; ArgentinaFil: Deza, Roberto Raul. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Grondona, Sebastian. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mascioli, S.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Martinez, Daniel Emilio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; Argentin

Brooding comatulids from the southwestern Atlantic, Argentina (Echinodermata: Crinoidea)

Isometra vivipara and Phrixometra nutrix are two brooding feather stars (order Comatulida) that are widely distributed along the southern tip of South America to the Antarctic. We examined 210 specimens of I. vivipara and 38 specimens of P.nutrix collected during five cruises in the southwestern Atlantic between 91 and 642 m depth. Specimens were analyzed and deposited in the National Invertebrate collection, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Isometravivipara reaches an arm length of 49 mm long and shows two stages of brooding: in the female genital pinnules and on the cirri of the mother. In this paper, we propose that spermatozoa reach the ovary via the ambulacral groove. By contrast, P. nutrix is smaller with a maximum recorded size of 26.8 mm, and brooding occurs only inside the female genital pinnules. Here, we record, for the first time for P.nutrix, spermatozoa shape and a cleaved egg attached externally to a genital pinnule of a female. The distributions of both species and their abundances in some areas could be related to their doliolaria larval stage. In addition, we extend the bathymetric range of P.nutrix to 512 m in Marine Protected Area Namuncurá/Burdwood Bank and distribution to the Mar del Plata Submarine Canyon area. We also propose mode of reproduction and developmental patterns as attributes for identification and possible explanations for their differences in distribution.Fil: Pertossi, Renata Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Penchazadeh, Pablo E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad Simón Bolívar; VenezuelaFil: Martinez, Mariano Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

The Drivers of Acute Seasonal Infectious Diseases.

Seasonality is a feature of all ecological systems. Earth's terrestrial and pelagic life has evolved in a highly seasonal abiotic environment with intra-annual variation in photoperiod, temperature, and precipitation, among many other abiotic and biotic factors. Seasonal aspects of mammals and birds include seasonally varying birth rates, seasonal changes in endocrine hormones, and seasonal variation in immunity. One area where seasonal biology is particularly salient is disease ecology. The mechanisms underlying the seasonality of communicable diseases are poorly understood. I propose that much of the unexplained seasonality observed in infectious disease dynamics could be attributed to seasonal biology, including (1) birth seasonality, (2) seasonal variation in immunity, and (3) seasonal cycles in parasite traits and parasite population parameters. In my dissertation, I present work on various aspects of seasonality. In Chapter II, I explored the seasonality of births in human populations and quantified the effects of birth seasonality on measles epidemics. In Chapter III, I reviewed circadian and circannual rhythms in host and parasite populations, and proposed both ecological and evolutionary models for integrating biological rhythms into the study of infectious diseases. In Chapters IV--V, I presented my in-depth ecological studies of poliovirus, a notoriously seasonal summertime infection. I explored geographical variation in polio's seasonality and tested whether human birth seasonality or transmission seasonality drove epidemics of this disease. In addition to studying polio seasonality, I revealed the connection between (i) polio's emergence and human demography, (ii) the geographical distribution of poliovirus and its persistence, and (iii) polio symptomatology and silent chains of transmission. Lastly, I highlighted the public health implications of seasonal transmission by measuring the efficacy of the two polio vaccines and discussing how seasonality can be utilized for vaccine interventions.PhDEcology and Evolutionary BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/113643/1/bakkerma_1.pd

Transcriptional Elongation and mRNA Export Are Coregulated Processes

Chromatin structure complexity requires the interaction and coordinated work of a multiplicity of factors at different transcriptional regulation stages. Transcription control comprises a set of processes that ensures proper balance in the gene expression under different conditions, such as signals, metabolic states, or development. We could frame those steps from epigenetic marks to mRNA stability to support the holistic view of a fine-tune balance of final mRNA levels through mRNA transcription, export, stability, translation, and degradation. Transport of mRNA from the nucleus to the cytoplasm is a key process in regulated gene expression. Transcriptional elongation and mRNA export are coregulated steps that determine the mature mRNA levels in the cytoplasm. In this paper, recent insights into the coordination of these processes in eukaryotes will be summarised

Digital Epidemiology Reveals Global Childhood Disease Seasonality and the Effects of Immunization

ACKNOWLEDGMENTS. We would like to thank Fernando Gonzalez-Dominguez and Gilberto Vaughan for providing the chicken pox case reports from Mexico, and the Estonia Health Board, Department of Communicable Disease Surveillance and Control, for Estonian chicken pox case reports. KB would like to thank Mercedes Pascual, her lab, and Marisa Eisenberg for helpful comments. Jesus Cantu (research assistant, Princeton University) translated and categorized chicken pox searches from Mexico, Thailand, Australia, and the US.Peer reviewedPostprintPostprin

Multiplication in vitro of Myrocarpus Frondosus Allemão "incienso" from seeds establishment

Myrocarpus frondosus Allemão “incienso” es una especie leñosa con aptitudes maderables, la tala selectiva y la reducción de la superficie boscosa ha llevado a su disminución y consecuente pérdida de variabilidad genética. La propagación in vitro es una herramienta para la conservación de germoplasma y la propagación de árboles selectos. El presente trabajo tuvo como objetivo desarrollar la fase de establecimiento y multiplicación in vitro de M. frondosus. Se ensayaron tratamientos de desinfección en semillas para su establecimiento utilizando, hipoclorito de sodio en distintas concentraciones y tiempo de exposición. En la multiplicación de ápices y segmentos nodales de plántulas in vitro se estudiaron diferentes concentraciones de 6-Bencilaminopurina (6-BAP, 0,1; 0,25; 0,5 y 1 mg/L) y ácido naftalenacético (ANA, 0,1 mg/L). Se obtuvo en el establecimiento de semillas un 6,5% de germinación al tratarlas con solución de hipoclorito de sodio al 3%. La mejor respuesta en la multiplicación se logró con la concentración ensayada de 1 mg/L de 6-BAP y 0,1 mg/L de ANA.Myrocarpus frondosus Allemão “incienso” is a species with excellent qualities for timber. Its selective felling combined with the loss of woodland as a result of advancing agriculture areas has reduced its presence and as a consequence the loss of genetic variability. The micropropagation of vegetal species offers an important tool for conserving germoplasm and for propagating selected trees. The objective of the present research work consisted in developing a protocol for establishment and multiplication of M. frondosus. Different disinfection treatments for seeds were tested with sodium hypochlorite solution at different concentrations and exposition times. In the multiplication phase, different treatments were tested with 6-Bencilaminopurina (6-BAP at 0,1; 0,25; 0,5 y 1 mg/L) y Naftalenacetic acid (ANA at 0,1 mg/L). For establishment a 6,5 % of germination was obtained in the treatment with a sodium hypochlorite solution at 3%. The best answer in the multiplication was obtained with 1 mg/L 6-BAP and 0,1 mg/L ANA concentrations.Fil: Noguera, Ana Maria. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; ArgentinaFil: Martinez, Micaela Evelin. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; ArgentinaFil: Padilla, Cristina Raquel. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; ArgentinaFil: Duarte, Paola Fernanda. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentin

Determinación de oficio y sanciones en el marco de la Ley nº 27430

El presente trabajo tiene como finalidad el abordaje del Procedimiento de Determinación de Oficio llevado adelante por el Organismo Recaudador a Nivel Nacional “A.F.I.P." luego de la Reforma Impositiva aprobada en el año 2.017 según Ley 27.430. El mencionado modo de proceder es realizado por A.F.I.P. con la finalidad de evitar la evasión de tributos nacionales a través de la determinación de la base imponible ante la omisión del contribuyente de la presentación de Declaraciones Juradas o bien ante la detección de errores en las mismas. Este trabajo persigue como objetivo el brindar un conocimiento actualizado acerca del Procedimiento de Determinación de Oficio en lo que se refiere a los pasos a seguir y herramientas con las que cuenta el Organismo para realizarlo como así también establecer cuales son los derechos del contribuyente ante el mismo, medios de prueba a ofrecer y recursos que puede interponer.Fil: Martinez, Brenda Rocío. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: Russo, Leiza Micaela. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas

Carbon footprint of lamb and Wool production at farm gate and the regional sale in southern Patagonia

Natural steppe grasslands are the principal food resource for sheep in the Patagonia region, reared for meat and wool. However, there is currently a concern about the relationship between ruminant livestock and climate change due to its contribution to anthropogenic greenhouse gas (GHG) emissions. The objective of this study was to determine the carbon footprints (CF) of sheep meat (lamb) and wool on a range of farms using empirical data collected on farm and then upscaled to the regional scale using models that use topographic, climatic, and vegetation indices as independent variables. At the regional level, the total CF of lamb and wool (the combination of emissions produced on farm, via transport, and via industrial processing) varied from 10.64 to 41.32 kg CO2-eq/kg for lamb meat (carcass) and from 7.83 to 18.70 kg CO2-eq/kg for fine-grade wool. For both, the predominant contribution was from primary production on-farm (75–90%), followed by industrial processing (2–15%), and transportation. We used multiple regression models to produce maps of lamb and wool CF at farm gate across Santa Cruz province. The model for variation of lamb CF explained 95% of the variance on the data and the most significant predictor variables were temperature seasonality and normalized difference vegetation index (NDVI, dimensionless). The most important variables for the model of CF of greasy wool production at farm gate were isothermality, temperature seasonality, and NDVI explained 98%. The lowest CF values of both products (lamb and wool) were located in more productive grasslands. The successful management of livestock GHG emissions becomes an important challenge to the scientific, commercial, and policy communities. The results of CF for lamb and wool production found in the present work assist in characterizing the greenhouse gas emissions profile of livestock products in Southern Patagonia by providing a baseline against which mitigation actions can be planned and progress monitoredEEA SANTA CRUZFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral (UNPA). Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Rosas, Yamina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Centro Austral de Investigaciones Científicas (CADIC). Ushuaia, Tierra del Fuego; Argentina.Fil: Ladd, Brenton. Universidad Científica del Sur. Escuela de Agroforestería. Lima; Perú.Fil: Díaz-Delgado, Ricardo. Estación Biológica de Doñana (CSIC). Laboratorio de SIG y Teledetección. Sevilla; España.Fil: Martínez Pastur, Guillermo J. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Centro Austral de Investigaciones Científicas (CADIC).Ushuaia, Tierra del Fuego; Argentina

Antifungal activity of yacon (Smallanthus sonchifolius) extract against candida spp.

Introduction: Yacon (Smallanthus sonchifolius) is a functional food, rich in fructooligosaccharides, and has been widely used in scientific research, showing effects in reducing lipid and glycemic levels, in addition to having antibacterial, antioxidant and neuroprotective properties. The objective was to evaluate the hydroalcoholic extract of yacon leaf in Candida species. Methods: Thirty-three samples of different species of the genus Candida treated with yacon leaf extract at concentrations of 25 to 400ug/ml were analyzed using the Minimum Inhibitory Concentration method described by the M27-A3 protocol of the Clinical and Laboratory Standards Institute. Results: Among the species of C. albicans, 16 samples showed sensitivity to the extract at the concentrations used. Conclusion: Yeasts of the Candida genus are able to adapt to different environments due to their high degree of resistance to antifungal agents, making it increasingly necessary to use natural substances as alternatives for the treatment of diseases caused by fungi. The antifungal activity of yacon leaf extract against fungi of the genus Candida is being reported for the first time in this study, making yacon a new therapeutic alternative