29 results match your criteria: "Univ. de Buenos Aires[Affiliation]"

The Effects of a Male Audience on Male and Female Mating Behaviour in the Blood-Sucking Bug Rhodnius prolixus.

Neotrop Entomol

April 2022

Lab de Fisiología de Insectos, Depto de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Univ de Buenos Aires, IBBEA, CONICET-UBA, Buenos Aires, Argentina.

Social context is a key factor affecting sexual behaviour and cannot be neglected in gregarious species, such as triatomine blood-sucking bugs. Here we study the influence of the social context on the sexual reproductive behaviour of males and females of Rhodnius prolixus Stål. Specifically, we identify and compare the frequencies and sequence of sexual behaviours exhibited by a focal pair in presence or absence of a male audience.

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Loss of biodiversity and accumulation of contaminants in urban soils and water bodies cause serious issues in metropolitan areas. The Matanza-Riachuelo river basin (metropolitan area of Buenos Aires, Argentina) is one of the most environmentally degraded regions in the world. Senecio bonariensis Hook & Arn (Asteraceae) grows in the periodically flooded soils of this wetland.

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Midgut Genes Knockdown by Oral dsRNA Administration Produces a Lethal Effect on Cotton Boll Weevil.

Neotrop Entomol

February 2021

Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Lab de Agrobiotecnología DFBMC, Facultad de Ciencias Exactas y Naturales, Univ de Buenos Aires, Buenos Aires, Argentina.

The "cotton boll weevil" (Anthonomus grandis Boheman) is a key pest in America whose larval stage develops within the cotton flower bud. During its development, the larva uses the flower bud as food and as a shelter from predators. This behavior limits the effective control through conventional insecticide applications and biocontrol techniques.

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The cortical and subcortical circuit regulating both cognition and cardiac autonomic interactions are already well established. This circuit has mainly been analyzed from cortex to heart. Thus, the heart rate variability (HRV) is usually considered a reflection of cortical activity.

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[Streptococcus pyogenes meningitis: a pediatric case report].

Arch Argent Pediatr

June 2020

Departamento de Salud Materno Infantil, Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina.

Beta hemolytic particularly of group A Streptococcus meningitis, is a rare site of the group of invasive infections caused by this microorganism. It occurs frequently in healthy children, without predisposing factors. It represents 0.

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No Vertical Stratification Found in Cavity-Nesting bees and Wasps in Two Neotropical Forests of Argentina.

Neotrop Entomol

October 2019

Instituto Argentino de Investigaciones de las Zonas Áridas, Mendoza, Argentina.

Vertical stratification is known in diverse arthropod communities in forests, but little is known about nesting ecology of trap-nesting bees and wasps in Neotropical forests. We studied the vertical colonization of trap-nests by solitary bees and wasps in two forests in Argentina. We obtained 204 nests of seven bee and six wasp species, with 1040 brood cells from which 660 hosts and 32 parasites (21 parasitoid and 11 kleptoparasite) adults emerged from four groups (five species of wasps [Chrysididae, Eulophidae, and Ichneumonidae], four flies [Bombyliidae and Sarcophagidae], three bees [Apidae and Megachilidae], and one species of beetle [Meloidae]).

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The role of heterocytes in the physiology and ecology of bloom-forming harmful cyanobacteria.

Harmful Algae

December 2016

Laboratorio de Limnología (Lab. 44, 4to piso), Dpto. de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales (Pab. II), Univ. de Buenos aires (UBA), IEGEBA (CONICET-UBA), Intendente Güiraldes 2620, C1428EHA, Buenos Aires, Argentina; Department of Integrative Biology, Ecology, Evolutionary Biology and Behavior Program, W.K. Kellogg Biological Station, Michigan State Univ., 3700 East Gull Lake Dr., Hickory Corners, MI 49060, USA. Electronic address:

Dolichospermum flos-aquae and Cylindrospermopsis raciborskii are two cyanobacteria species which cause harmful blooms around the world. Both these species share the capacity to fix atmospheric nitrogen in heterocytes (cell where fixation occurs). While Dolichospermum can express heterocytes at rather regular intervals across the filament, Cylindrospermopsis can only express heterocytes at the end of the filament.

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Coarse-Grained Simulations of Heme Proteins: Validation and Study of Large Conformational Transitions.

J Chem Theory Comput

July 2016

Dto. de Química Inorgánica, Analítica y Química Física, Fac. de Ciencias Exactas y Naturales, Univ. de Buenos Aires/INQUIMAE-CONICET, Buenos Aires, C1428EGA, Argentina.

Heme proteins are ubiquitous in nature and perform many diverse functions in all kingdoms of life. Many of these functions are related to large-scale conformational transitions and allosteric processes. Sampling of these large conformational changes is computationally very challenging.

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First Record of Drosophila buzzatii (Patterson & Wheeler) (Diptera: Drosophilidae) Emerging from a Non-Cactus Host.

Neotrop Entomol

June 2016

Depto de Ecología, Genética y Evolución, Fac de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón II, Univ de Buenos Aires, Buenos Aires, 1428, Argentina.

Drosophila buzzatii (Patterson & Wheeler), a typical cactophilic species of the repleta group, is registered for the first time emerging from Melon (Cucumis melo) in western Argentina. The analysis of inversion polymorphism and genetic diversity of mitochondrial cytochrome oxidase subunit I gene (mtCOI) provided additional evidence that corroborated the presence of a high proportion of D. buzzatii among the flies emerged from melon.

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CG2AA: backmapping protein coarse-grained structures.

Bioinformatics

April 2016

Dto. De Química Inorgánica, Analítica Y Química Física - INQUIMAE-CONICET, Fac. De Ciencias Exactas Y Naturales, Univ. De Buenos Aires, Cdad. Universitaria, CABA C1428EGA, Argentina.

Unlabelled: Coarse grain (CG) models allow long-scale simulations with a much lower computational cost than that of all-atom simulations. However, the absence of atomistic detail impedes the analysis of specific atomic interactions that are determinant in most interesting biomolecular processes. In order to study these phenomena, it is necessary to reconstruct the atomistic structure from the CG representation.

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Accumulation of beef cattle manure on feedlot pen surfaces generates large amounts of dissolved solutes that can be mobilized by water fluxes, affecting surface and groundwater quality. Our objective was to examine the long-term impacts of a beef cattle feeding operation on water fluxes and manure leaching in feedlot pens located on sandy loam soils of the subhumid Sandy Pampa region in Argentina. Bulk density, gravimetric moisture content, and chloride concentration were quantified.

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Temperature effects on the immature development time of Culex eduardoi Casal & García (Diptera: Culicidae).

Neotrop Entomol

August 2011

Grupo de Estudio de Mosquitos, Facultad de Ciencias Exactas y Naturales, Univ de Buenos Aires, Buenos Aires, Argentina.

The effect of constant temperatures on the development time from first instar to adult emergence was studied in Culex eduardoi Casal & García reared at 7, 10, 15, 20, 25, 30 or 33°C. Data were adjusted to the linear degree-day model and the nonlinear Briére model. According to the linear model, the development time was inversely related to the rearing temperatures between 7°C and 25°C.

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The objective was to study atrial natriuretic peptide (ANP) effects on mean arterial pressure (MAP) and cardiovascular nitric oxide (NO) system in spontaneously hypertensive rats (SHRs), investigating the receptors and signaling pathways involved. In vivo, SHRs and Wistar-Kyoto (WKY) rats were infused with saline (0.05 ml/min) or ANP (0.

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A longitudinal study of two species of Belostoma Latreille (Heteroptera: Belostomatidae): allometry and ontogeny.

Neotrop Entomol

April 2009

Depto. de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires, Argentina.

The multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of Belostoma elegans (Mayr) and B. cummingsi De Carlo are presented for the first time, and the allometric coefficients are compared. The segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs.

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Biophysical properties of epithelial water channels.

Biophys Chem

October 1997

Laboratorio de Biomembranas, Departamento de Fisiología, Facultad de Medicina, Univ. de Buenos Aires, Argentina.

The biophysical models describing the structure of water pores or channels have evolved, during the last forty years, from a pure 'black box' approach to a molecular based proposal. The initial 'sieving pore' in which water and other molecules were moving together was replaced by a more restrictive model, where water is moving alone in a 'single file' mode. Aquaporins discovery and cloning [G.

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Achiasmatic male meiosis in Tenagobia (Fuscagobia) fuscata (Stål) (Heteroptera, Corixoidea, Micronectidae).

Genetica

October 2004

Laboratorio de Citogenética y Evolución, Depto de Ecología, Genética y Evolución, Fac Cs Exactas y Naturales, Univ de Buenos Aires Int Güiraldes y C Norte, C1428EHA, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina.

Male karyotype and meiosis of Tenagobia fuscata (Corixoidea, Micronectidae) are studied. The species possesses a male diploid chromosome number 2n = 28 + XY, holokinetic chromosomes, absence of m chromosomes and an achiasmatic male meiosis. Autosomes divide pre-reductionally while the sex chromosomes do so post-reductionally.

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Behaviour of ring bivalents in holokinetic systems: alternative sites of spindle attachment in Pachylis argentinus and Nezara viridula (Heteroptera).

Chromosome Res

August 2004

Lab. de Citogenéticca y Evolución, Depto. de Ecología, Genética y Evolución, Fac. Cs. Exactas y Naturales, Univ. de Buenos Aires. Int. Güiraldes y C. Norte, C1428EHA, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, Argentina.

Heteropteran chromosomes are holokinetic; during mitosis, sister chromatids segregate parallel to each other but, during meiosis, kinetic activity is restricted to one pair of telomeric regions. This meiotic behaviour has been corroborated for all rod bivalents. For ring bivalents, we have previously proposed that one of the two chiasmata releases first, and a telokinetic activity is also achieved.

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[Phenomenology and psychosomatics].

Vertex

December 2002

Reg. de la Univ. de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.

By dividing the field of the human, the psyche-soma dualism ended in sectorizing diseases into organic illnesses, and psychic illnesses. Eventually, however, the so-called 'psychosomatic disorders' that, apparently, had broken up such a pattern have been converted to a new corpus pineale just as Descartes would have done. The body is reduced to a mere instrument of psyche, and the subject is reduced to a mere onlooker of illness he or she tries to remove one way or the other.

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Differential role of Na+/H+ exchange isoforms NHE-1 and NHE-2 in a rat cortical collecting duct cell line.

J Membr Biol

November 2002

Laboratorio de Biomembranas, Depto de Fisiología, Facultad de Medicina, Univ. de Buenos Aires, Paraguay 2155, Piso 7, 1121 Buenos Aires, Argentina.

The Na+/H+ exchanger (NHE) constitutes a gene family containing several isoforms that display different membrane localization and are involved in specialized functions. Although basolateral NHE-1 activity was described in the cortical collecting duct (CCD), the localization and function of other NHE isoforms is not yet clear, This study examines the expression, localization, and regulation of NHE isoforms in a rat cortical collecting duct cell line (RCCD1) that has previously been shown to be a good model of CCD cells. Present studies demonstrate the presence of NHE-1 and NHE-2 isoforms, but not NHE-3 and NHE-4, in RCCD1 cells.

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Routine Y-STR typing in forensic casework.

Forensic Sci Int

May 2001

Servicio de Huellas Digitales Genéticas y Cát. de Genét. y Biol. Molecular, Fac. de Farmacia y Bioquímica, Univ. de Buenos Aires, Junin 956, 1113, Buenos Aires, Argentina.

In the field of molecular diagnosis, forensic casework analysis is one of the most demanding investigations, due to its social impact. Optimization of DNA typing multiplex reactions with identical cycling conditions as those required by autosomal short tandem repeats (STR) multiplex reduces errors, and saves time and reagents. Previously, we validated a five Y-STRs set, all of them generating single band patterns.

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Transepithelial water movements and arginine-vasopressin (AVP)-associated ones were studied in a renal cell line established from a rat cortical collecting duct (RCCD(1)). Transepithelial net water fluxes (J(w)) were recorded every minute in RCCD(1) monolayers cultured on permeable supports. Spontaneous net water secretion was observed, which was inhibited by serosal bumetanide (10(-5) m), apical glibenclamide (10(-4) m) and apical BaCl(2) (5 x 10(-3) m).

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Minute-by-minute net water fluxes (Jw) were measured across the isolated rectal epithelium in rats and rabbits. Five minutes after a serosal (but not mucosal) hypertonic challenge (plus 200 mosmol/l) a significant increase in the basal Jw was recorded in both species [deltaJw, microl min(-1) cm(-2): 0.40+/-0.

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Water permeability in rat oocytes at different maturity stages: aquaporin-9 expression.

J Membr Biol

July 2000

Laboratorio de Biomembranas, Dpto. de Fisiología, Fac. de Medicina, Univ. de Buenos Aires, Argentina.

Important functional and structural modifications occur in mammalian oocytes during their arrival to maturity. In this process, oocytes switch from a high activity level, implying an important metabolic rate and a coordinated movement of water and solutes, to a lower functional state. The aim of this work was to study the mechanisms involved in water movements during oocyte arrival to maturity.

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Transepithelial water permeability was measured in LLC-PK1 cells stably transfected with aquaporins (AQPs): AQP1, AQP2, and a chimera of AQP1 and AQP2 containing 41 amino acids of the C-terminus of AQP2. Transepithelial water fluxes (Jw) were not previously reported in cells transfected with aquaporins. Jw were now recorded each minute using a specially developed experimental device.

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