Death, personhood, and relatedness in the South Andes a thousand years ago Acuto, Felix Alejandro; Kergaravat, Marisa Soledad; Amuedo, Claudia Gabriela This article examines the nature of personhood in the Calchaquí region, in the South Andes,during the second part of the Late Intermediate Period (AD 1250?1450). Through the study of the location of graves, architecture, and offerings, the authors explore the type of personhood that Calchaquí communities built and represented through the materiality of funerary practice. They claim that in this cultural and historical context, death became a realm in which relatedness was interwoven. Death, symbolically and materially, built bridges, connecting and entangling people with place and with each other. The funerary sphere was not strategically used to celebrate particular biographies and personal accomplishments, but rather it was another realm, like daily life, where individual identity dissolved into place and into the collective.

Pensar el Estado a partir de la filosofía de Alain Badiou; Thinking about the State Based on the Philosophy of Alain Badiou Farrán, Roque En este artículo se presenta el concepto de estado que elabora Alain Badiou, en su dimensión ontológico-política, a fin de ensayar una modulación propia del concepto acorde con la especificidad de la problemática latinoamericana y la resignificación del Estado en los procesos políticos que tienen lugar en la región.; In this article, the concept of the state formulated by Alain Badiou is presented in its ontological-political dimension, in order to try a modulation belonging to the concept that agrees with the specificity of Latin American issues and the redefinition of the State in the political processes taking place in the region.

Ultrasound as a Method to Control Protein-Polysaccharide Foam Stability by Microscopic Parameter Alteration Martínez, Karina Dafne; Carrera-sánchez, Cecilio The objective of this work was to determine the effect of ultrasound application on the stability of foams of mixed systems of soy protein isolate and a hydroxypropyl methylcellulose called E4M at pH 7 and 3. It was used a soluble fraction of soy protein which is the responsible of functional properties in food applications. The pHs selected were used according to normally range in food meals. The samples were sonicated for 20 min using an ultrasonic processor Vibra Cell Sonics model VCX 750 at a frequency of 20 kHz and an amplitude of 20%. The foams were produced using a foaming instrument with a second CCD camera. The relative foam conductance (Cf%) and complementary parameters: half-life time, t½; relaxation times corresponding to the kinetics of liquid drainage, td; and disproportionation and collapse, tdc, were obtained. Significant differences were found for the relaxation times td and tdc at pH 7 as a consequence of the ultrasound treatment. It could be seen that ultrasound promoted a great increment of these relaxation times in these conditions, attributed to quantity of proteins at different pH.

Genome downsizing and karyotype constancy in diploid and polyploid congeners: a model of genome size variation Poggio, Lidia; Realini, Maria Florencia; Fourastié, María Florencia; Garcia, Ana Maria; González, Graciela Esther Evolutionary chromosome change involves significant variation in DNA amount in diploids and genome downsizing in polyploids. Genome size and karyotype parameters of Hippeastrum species with different ploidy level were analysed. In Hippeastrum, polyploid species show less DNA content per basic genome than diploid species. The rate of variation is lower at higher ploidy levels. All the species have a basic number x = 11 and bimodal karyotypes. The basic karyotypes consist of four short metacentric chromosomes and seven large chromosomes (submetacentric and subtelocentric). The bimodal karyotype is preserved maintaining the relative proportions of members of the haploid chromosome set, even in the presence of genome downsizing. The constancy of the karyotype is maintained because changes in DNA amount are proportional to the length of the whole-chromosome complement and vary independently in the long and short sets of chromosomes. This karyotype constancy in taxa of Hippeastrum with different genome size and ploidy level indicates that the distribution of extra DNA within the complement is not at random and suggests the presence of mechanisms selecting for constancy, or against changes, in karyotype morphology.

Application of hydrogen peroxide to the control of eutrophic lake systems in laboratory assays Bauzá, Letizia; Aguilera, Anabella; Etchenique, Roberto Argentino; Andrinolo, Dario; Giannuzzi, Leda We exposed water samples from a recreational lake dominated by the cyanobacterium Planktothrix agardhii to different concentrations of hydrogen peroxide (H2O2). An addition of 0.33 mg·L−1 of H2O2 was the lowest effective dose for the decay of chlorophyll-a concentration to half of the original in 14 h with light and 17 h in experiments without light. With 3.33 mg·L−1 of H2O2, the values of the chemical oxygen demand (COD) decreased to half at 36 and 126 h in experiments performed with and without light, respectively. With increasing H2O2, there is a decrease in the total and faecal coliform, and this effect was made more pronounced by light. Total and faecal coliform were inhibited completely 48 h after addition of 3.33 mg·L−1 H2O2. Although the densities of cyanobacterial cells exposed to H2O2 did not decrease, transmission electron microscope observation of the trichomes showed several stages of degeneration, and the cells were collapsed after 48 h of 3.33 mg·L−1 of H2O2 addition in the presence of light. Our results demonstrate that H2O2 could be potentially used in hypertrophic systems because it not only collapses cyanobacterial cells and coliform bacteria but may also reduce chlorophyll-a content and chemical oxygen demand.

Nanofiltration of glucose: Analysis of parameters and membrane characterization Almazán, Jorge Emilio; Romero Dondiz, Estela María; Rajal, Verónica Beatriz; Castro Vidaurre, Elza Fani Membrane characterization and modeling of nanofiltration processes of uncharged solutes are of special interest for the food industry. In this work two commercial membranes, DK and DL, were used to concentrate glucose solutions. Membranes were characterized according hydrophobicity, thickness, porosity, and hydraulic permeability. The influence of pressure and concentration of glucose on the permeate flux and rejection were studied. Both membranes presented a great potential for the food industry due to their high rejection of glucose. The osmotic pressure model was combined with film theory and the real driven force was calculated taking into account the osmotic pressure and the concentration polarization. Both phenomena influenced the process (concentration polarization only in the most dilute solutions at low pressure) and the permeability for glucose solutions was similar to the hydraulic permeability. A mathematical model based on the Donnan-Steric Pore Model was used to determine the pore radius and the effective thickness of both membranes. As the concentration inside the pore (needed for the calculations) is difficult to measure experimentally, various alternatives were proposed. The average of the concentration at the interface and permeate best fitted the experimental data. The model was applied successfully; the maximum error was 8% within the range of concentrations (5–100 g/L) for the DL membrane and 5% for the DK membrane up to 50 g/L.

Monopelopia caraguata (Chironomidae: Tanypodinae: Pentaneurini) and Phytotelmatocladius delarosai (Chironomidae: Orthocladiinae): Two Phytotelmatous Chironomids Distributed from Florida to Argentina Siri, Augusto; Donato, Mariano Humberto The geographic distribution of the 2 phytotelmatous chironomids Monopelopia caraguata and Phytotelmatocladius delarosai is expanded, and the occurrence of parthenogenesis in the last species is corroborated under laboratory conditions.; Se extiende la distribución geográfica de las especies fitotelmáticas Monopelopia caraguata y Phytotelmatocladius delarosai hacia el sur en Argentina, y se corrobora bajo condiciones de laboratorio la ocurrencia de partenogénesis en esta última especie.

Caveolinas y modulación del sistema del óxido nítrico en el hipotiroidismo según avanza la edad.; Age-related influence of hypothyroidism on caveolins and nitric oxide modulation Detomaso, Florencia M.; Braga, Paula; Rodríguez, Lourdes; Arreche, Noelia Daniela; Sarati, Lorena Ivonne; Balaszczuk, Ana María; Fellet, Andrea L. Introduction: Hypothyroidism and age impact on cardiac and renal nitricoxide (NO) production. Caveolins, which are negativemodulators of NO synthase (NOS) activity, are affected byboth factors. Objectives: The aim of this study was to evaluate caveolin (CAV) participationin the modulation of renal and cardiac NOS activityin adult hypothyroid animals. Methods: Euthyroid and hypothyroid [methimazole 0.02% (v/v) in thedrinking water during 28 days] male Sprague-Dawley ratswere used. Animals were sacrificed to remove the heart andkidneys. Results: Right atrial NOS activity decreased with age and hypothyroidism.Caveolin-1 expression increased with age andhypothyroidism. Conversely, left ventricular NOS activityincreased with aging and hypothyroidism and the expressionof both CAV isoforms decreased in adult and hypothyroidgroups. In the renal medulla, hypothyroidism reducedNOS activity in young and raised it in adult animals andCAV-1 expression decreased with age and in hypothyroidyoung animals. Caveolin-3 protein levels decreased in adulthypothyroid animals. Conclusions: Hypothyroidism impacts on NOS activity and on that ofits modulators, caveolins, in the cardiovascular and renalsystems. Hypothyroidism enhances the effects of aging inboth systems.

Divergent synthetic routes to biologically relevant types of compounds: chiral polyfunctional γ-lactams and amino acids Aguilera, Jordi; Moglioni, Albertina Gladys; Mor, Àlex; Ospina, Jimena; Illa, Ona; Ortuño, Rosa M. Divergent and versatile synthetic routes leading to the title compounds are described. They start from a common chiral precursor derived from (−)-(S)-verbenone and afford polyfunctional γ-lactams and γ- and ε-amino acids. The cyclobutane moiety in these molecules acts as a chiral and polyfunctional platform providing stereogenic centres with unambiguous absolute configuration that control the chirality of the newly produced asymmetric carbons. Furthermore, it affords functional groups and carbon chains suitable not only to create the basic skeleton of the desired products but additional functional groups. These features confer on these derivatives a great versatility for further uses in the development of new drugs and as synthetic building blocks.

Expression, localization and function of galectin-8, a tandem-repeat lectin, in human tumors Elola, Maria Teresa; Ferragut, Fátima; Cardenas Delgado, Victor Manuel; Nugnes, Lorena Gisela; Gentilini, Lucas Daniel; Laderach, Diego Jose; Troncoso, María Fernanda; Compagno, Daniel Georges; Wolfenstein, Carlota Elisa; Rabinovich, Gabriel Adrian Galectin-8 (Gal-8) is a ‘tandem-repeat’-type galectin, which possesses two carbohydrate recognition domains connected by a linker peptide. Gal-8 complexity is related to the alternative splicing of its mRNA precursor, which is known to generate isoforms. Regarding its carbohydrate-binding specificity, Gal-8 has a unique feature among galectins, since its C-terminal domain has higher affinity for N-glycan-type branched oligosaccharides, while its N-terminal domain shows strong affinity for α2-3-sialylated or 3’-sulfated ß-galactosides. We integrate here the available information on Gal-8 expression in different tumor types and attempt to elucidate associations of its expression and localization during tumor progression with the overarching goal of analyzing its potential applications in diagnosis and prognosis. Differential diagnosis is still a prime concern in tumor pathology, and Gal-8 could be of great value in some types of primary or secondary tumors (i.e. papillary thyroid carcinoma, advanced colon carcinoma from patients with distant metastases, or metastases from primary lung carcinoma). The prognostic value of Gal-8 has been described for laryngeal carcinoma as well as advanced colon carcinoma. Further studies are needed to explain the relevance of Gal-8 and its isoforms in tumor pathology and their different intra- or extracellular roles (cytoplasmic, nuclear or extracellular) in tumor biology.

Unveiling a crystalline topological insulator in a Weyl semimetal with time-reversal symmetry Arrachea, Liliana del Carmen; Aligia, Armando Angel We consider a natural generalization of the lattice model for a periodic array of two layers, A and B , of spinless electrons proposed by Fu [Phys. Rev. Lett. 106, 106802 (2011)] as a prototype for a crystalline insulator. This model has time-reversal symmetry and broken inversion symmetry. We show that when the intralayer next-nearest-neighbor hoppings t a 2 , a = A , B vanish, this model supports a Weyl semimetal phase for a wide range of the remaining model parameters. When the effect of t a 2 is considered, topological crystalline insulating phases take place within the Weyl semimetal one. By mapping to an effective Weyl Hamiltonian we derive some analytical results for the phase diagram as well as for the structure of the nodes in the spectrum of the Weyl semimetal.

The proinflammatory RAGE/NF-κB pathway is involved in neuronal damage and reactive gliosis in a model of sleep apnea by intermittent hypoxia Angelo, María Florencia; Aguirre, Alejandra Inés; Aviles Reyes, Rolando Xavier; Villarreal, Alejandro; Lukin, Jeronimo; Melendez, Matías; Vanasco, Virginia; Barker, Philip A.; Alvarez, Silvia; Epstein, Alberto Luis; Jerusalinsky, Diana Alicia; Ramos, Alberto Javier Sleep apnea (SA) causes long-lasting changes in neuronal circuitry, which persist even in patients successfully treated for the acute effects of the disease. Evidence obtained from the intermittent hypoxia (IH) experimental model of SA has shown neuronal death, impairment in learning and memory and reactive gliosis that may account for cognitive and structural alterations observed in human patients. However, little is known about the mechanism controlling these deleterious effects that may be useful as therapeutic targets in SA. The Receptor for Advanced Glycation End products (RAGE) and its downstream effector Nuclear Factor Kappa B (NF-κB) have been related to neuronal death and astroglial conversion to the pro-inflammatory neurodegenerative phenotype. RAGE expression and its ligand S100B were shown to be increased in experimental models of SA. We here used dissociated mixed hippocampal cell cultures and male Wistar rats exposed to IH cycles and observed that NF-κB is activated in glial cells and neurons after IH. To disclose the relative contribution of the S100B/RAGE/NF-κB pathway to neuronal damage and reactive gliosis after IH we performed sequential loss of function studies using RAGE or S100B neutralizing antibodies, a herpes simplex virus (HSV)-derived amplicon vector that induces the expression of RAGEΔcyto (dominant negative RAGE) and a chemical blocker of NF-κB. Our results show that NF-κB activation peaks 3 days after IH exposure, and that RAGE or NF-κB blockage during this critical period significantly improves neuronal survival and reduces reactive gliosis. Both in vitro and in vivo, S100B blockage altered reactive gliosis but did not have significant effects on neuronal survival. We conclude that both RAGE and downstream NF-κB signaling are centrally involved in the neuronal alterations found in SA models, and that blockage of these pathways is a tempting strategy for preventing neuronal degeneration and reactive gliosis in SA.

Synthesis and characterization of water-soluble dendronized chitosan using newkome-type dendrons Rimondino, Guido Noé; Strumia, Miriam Cristina; Martinelli, Marisa With increasing emphasis on environmental care 7 and use of renewable resources, simple and effective dendroniza- 8 tion processes were performed to obtain chitosan derivatives. We 9 present different alternatives for the modification of chitosan: 10 dendronization with a biocompatible dendron; a quaternization 11 process with an ammonium salt, which confers a permanent 12 positive charge to the polymer; and a combination of method- 13 ologies allowing amphiphilic polymers. This process confers 14 unique multivalent properties to the native chitosan, and further 15 modifications reach multivalent water-soluble polymers. Hence, 16 the most important highlight of this work is the use of renewable 17 natural polymers and the different methodologies applied to nontoxic solvents with low temperatures. The process described in 18 this paper represents a sustainable alternative for obtaining a functionalized material with properties suitable for application in 19 different areas, such as biomedicine or environmental remediation.

Iodine Staining of Escherichia coli Expressing Genes Involved in the Synthesis of Bacterial Glycogen Demonte, Ana M.; Asención Diez, Matías Damián; Guerrero, Sergio Adrian; Ballicora, Miguel A.; Iglesias, Alberto Alvaro The presence of intracellular glycogen can be detected by the following iodine staining technique. Cells with glycogen stain dark brown, whereas in its absence they remain with a pale yellowish color. It is hypothesized that iodine atoms fit into helical coils formed by the α-polyglucan to form a coloured glycogen-iodine complex. Here, we have studied the expression of Streptococcus mutans (S. mutans) genes that control the biosynthesis of this polysaccharide. Thus, we expressed glgC and glgD genes coding for both ADP-Glc pyrophosphorylase subunits in Escherichia coli (E. coli) AC70R1-504 cells to complement the deficient accumulation of glycogen by this strain. In control cells or in those where an inactive protein was expressed, the synthesis of the polysaccharide was undetectable by this iodine staining technique.

Susceptibility of adults of the cerambycid beetle Hedypathes betulinus to the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae and Purpureocillium lilacinum Schapovaloff, María Elena; Alves, L. F. A.; Fanti, A. L.; Alzogaray, Raul Adolfo; Lopez Lastra, Claudia Cristina The cerambycid beetle Hedypathes betulinus (Klug) (Coleoptera: Cerambycidae) causes severe damage to yerba mate plants ( Ilex paraguariensis (St. Hilaire) (Aquifoliales: Aquifoliaceae)), which results in large losses of production. In this study, the pathogenicity of entomopathogenic fungi of the species Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae), Metarhizium anisopliae sensu lato (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae), and Purpureocillium lilacinum (Thom) Luangsa-ard, Hywel-Jones, Houbraken and Samson (Hypocreales: Ophiocordycipitaceae) on yerba mate were evaluated. Fifteen isolates of B. bassiana , two of M. anisopliae , and seven of P. lilacinum on H. betulinus adults were analyzed under laboratory conditions. The raw mortality rate caused by B. bassiana isolates varied from 51.1 to 86.3%, and their LT 50 values varied between 8.7 and 13.6 d. The isolates of M. anisopliae caused 69.6‒81.8% mortality, and their LT 50 values varied between 7.4 and 7.9 d. In contrast, isolates of P. lilacinum were not pathogenic. M. anisopliae and B. bassiana isolates were pathogenic against H. betulinus adults, suggesting that they may be useful in biological control programs for insect pests of yerba mate.

Systematics of the neotropical genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): phylogeny, the relevance of non-molecular evidence, and species accounts de Sá, Rafael O.; Grant, Taran; Camargo, Arley; Heyer, W. Ronald; Ponssa, María Laura; Stanley, Edward A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evidence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results support the monophyly of Leptodactylus sensu stricto, with Hydrolaetare placed as its sister group. The reciprocal monophyly of Hydrolaetare and Leptodactylus sensu stricto does not require that we consider Hydrolaetare as either a subgenus or synonym of Leptodactylus sensu lato. We recognize Leptodactylus sensu stricto, Hydrolaetare, Adenomera, and Lithodytes as valid monophyletic genera. Our results generally support the traditionally recognized Leptodactylus species groups, with exceptions involving only a few species that are easily accommodated without proposing new groups or significantly altering contents. The four groups form a pectinate tree, with the Leptodactylus fuscus group diverging first, followed by the L. pentadactylus group, which is sister to the L. latrans and L. melanonotus groups. To evaluate the impact of non-molecular evidence on our results, we compared our total evidence results with results obtained from analyses using only molecular data. Although non-molecular evidence comprised only 3.5% of the total evidence matrix, it had a strong impact on our total evidence results. Only one species group was monophyletic in the molecular-only analysis, and support differed in 86% of the 54 Leptodactylus clades that are shared by the results of the two analyses. Even though no non-molecular evidence was included for Hydrolaetare, exclusion of that data partition resulted in that genus being nested within Leptodactylus, demonstrating that the inclusion of a small amount of non-molecular evidence for a subset of species can alter not only the placement of those species, but also species that were not scored for those data. The evolution of several natural history and reproductive traits is considered in the light of our phylogenic framework. Invasion of rocky outcrops, larval oophagy, and use of underground reproductive chambers are restricted to species of the Leptodactylus fuscus and L. pentadactylus groups. In contrast, larval schooling, larval attendance, and more complex parental care are restricted to the L. latrans and L. melanonotus groups. Construction of foam nests is plesiomorphic in Leptodactylus but their placement varies extensively (e.g., underground chambers, surface of waterbodies, natural or excavated basins). Information on species synonymy, etymology, adult and larval morphology, advertisement call, and geographic distribution is summarized in species accounts for the 30 species of the Leptodactylus fuscus group, 17 species of the L. pentadactylus group, eight species of the L. latrans group, and 17 species of the L. melanonotus group, as well as the three species that are currently unassigned to any species group.; Se presenta una filogenia del género Leptodactylus, un clado neotropical rico en especies, basada en análises combinados de datos moleculares (marcadores nuclear y mitocondriales) y no moleculares (caracteres de la morfología de adultos y larvas así como de comportamiento) se muestrearon > 80% de las 75 especies reconocidas. Los resultados apoyan la monofília de Leptodactylus sensu stricto, con Hydrolaetare como su grupo hermano. La monofília recíproca de Hydrolaetare y Leptodactylus no requiere considerar a Hydrolaetare como un subgénero o sinónimo de Leptodactylus sensu lato. Se reconocen Leptodactylus sensu stricto, Hydrolaetare, Adenomera y Lithodytes como géneros monofiléticos válidos. Los resultados en general resuelven los grupos tradicionalmente reconocidos de Leptodactylus, con excepciones de algunas especies que son reasignadas sin la necesidad de proponer nuevos grupos o alterar significativamente el contenido de los grupos tradicionales. Los cuatro grupos de especies forman una topología pectinada donde el grupo de L. fuscus tiene una posición basal, seguido por el grupo de L. pentadactylus que es el grupo hermano al clado formado por los grupo de L. latrans y L. melanonotus. Se estimó el impacto de los datos no moleculares en los resultados, comparándose los resultados de evidencia total con los de los análises de datos moleculares solamente. Los datos no moleculares representan un 3.5% de la matriz de evidencia total, pero estos datos tuvieron un impacto significativo en los resultados del análisis de evidencia total. En el análisis estrictamente molecular solamente un grupo de especies resultó monofilético, y el apoyo difirió en 86% de los 54 clados de Leptodactylus compartidos entre los dos análises. A pesar que datos no moleculares no fueron incluídos para Hydrolaetare, la exclusión de evidencia no molecular resultó en el género estar dentro de Leptodactylus, demostrando que la inclusión de evidencia no molecular pequeña para un subgrupo de especies altera no solamente la posición topológica de esas especies, sino tambien de las especies para las cuales dichos datos no fueron codificados. La evolución de patrones de historia natural y reprodución se evalúan en el contexto filogenético. La invasión de afloramientos rocosos y la construción de cámaras de reprodución subterraneas está limitada a los grupos de Leptodactylus fuscus y L. pentadactylus, mientras que la oofagia larval está restringida al grupo de L. pentadactylus. Por otro lado, los cárdumenes larvales, la proteción del cárdumen, y otros comportamientos parentales complejos carecterizan al clado formado por los grupos de especies de L. latrans y L. melanonotus. Los resú- menes de especies incluyen información de sinonímias, etimología, morfología de adultos y larvas, cantos, y distribución geográfica para las 30 especies del grupo de Leptodactylus fuscus, 17 especies del grupo L. pentadactylus, ocho especies del grupo de L. latrans, 17 especies del grupo de L. melanonotus, así como para las tres especies que actualmente no se encuentran asociadas a ninguno de los grupos de especies.

Dimensional stability of materials based on Portland cement at the early stages Mesa Yandy, Angelica Maria; Zerbino, Raul Luis; Giaccio, Graciela M.; Russo, Nélida Araceli; Duchowicz, Ricardo In this work two fiber optic sensing techniques are used to study the dimensional stability in fresh state of different cementitious materials. A conventional Portland cement mortar and two commercial grouts were selected. The measurements were performed by using a Bragg grating embedded in the material and a non-contact Fizeau interferometer. The first technique was applied in a horizontal sample scheme, and the second one, by using a vertical configuration. In addition, a mechanical length comparator was used in the first case in order to compare the results. The evolution with time of the dimensional changes of the samples and the analysis of the observed behavior are included. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Stabilizing selection on nectar concentration in wild Petunia axillaris, as revealed by genetic analysis of pollen dispersal Gleiser, Gabriela Laura; Internicola, Antonina I.; Austerlitz, Frédéric; Bernasconi, Giorgina Most animal-pollinated plants produce nectar as a pollinator reward. Despite the main role that nectar plays in plant-pollinator interactions, the impact of natural variation in nectar traits on realized male fitness is poorly known. Here, we assessed this relation for a wild Petunia axillaris population using paternity-based direct selection gradient analysis, which allowed us also to infer pollen dispersal patterns. Because male fecundity may depend on other traits which could be associated with nectar characteristics (i.e. volume and concentration), we also considered selection on other key reproductive traits. The analysis revealed that P. axillaris was a strict outcrosser, but that successful pollination occurred mainly among neighbours. Individual plants varied greatly in their male fecundity. Nectar concentration, a key feature of nectar that determines its profitability, was subjected to stabilizing selection. Selection through male function also affected corolla area (positive directional selection), corolla tube length (negative directional selection), and floral display size (stabilizing selection), but none of these traits were phenotypically correlated with nectar characteristics. Because nectar concentration affects the ability and foraging efficiency of different flower visitors to feed on nectar, stabilizing selection may reflect either the preference of the most effective pollinators, or antagonistic selection driven by pollinators and non-pollinating nectar consumers.

Bioactivity of leucite containing glass-ceramics using natural raw materials Stábile, Franco Matías; Volzone, Cristina Glass compositions were carefully prepared, using natural quartz and potassium feldspar as a part of the starting raw materials. The solids were prepared so as to have theoretical stoichiometric leucite and 45S5 Bioglass in different L/Bg weight ratios between 0.43-1.00. Novel bioactive glass-ceramics, containing leucite, sodium calcium silicate and silicorhenanite, confirmed by XRD and FTIR, were obtained. Bioactivity tests were carried out on powdered and sintered disks forms. The immersion time was up to 25 days. Apatite formation on powders was studied by FTIR, and XRD and SEM were used to study bioactivity on disks. The materials developed an apatite layer on their surfaces within 6 days of immersion in simulated body fluid. The glass-ceramic with L/Bg ratio= 0.43 presented an apatite layer on all its surface, not so for the samples with 0.66 and 1.00 ratios, on which such layer was peeled off in most part of their surfaces.

Experimental and DFT study on the indiummediated synthesis of benzophenones via arylstannanes Lo Fiego, Marcos Jacinto; Dorn, Viviana B.; Badajoz, Mercedes A.; Lockhart, Maria T.; Chopa, Alicia B. Experimental results of the solvent-free, indium-promoted reaction of aroyl chlorides with arylstannanes showed a narrow scope; its efficiency depends both on the extent of methylation in the latter and on the nature, number and position of the substituents in the former. With the purpose of explaining experimental results, a theoretical analysis with DFT methods was performed for a set of selected cases.