Sindicador de canales de noticias
Reply to “Photoredox Catalysis: The Need to Elucidate the Photochemical Mechanism”
Ghosh, Indrajit; Bardagi, Javier Ivan; König, Burkhard
Spectroscopic measurements and estimated thermodynamic values are important tools for the investigation of photocatalytic reaction mechanisms. However, data derived under idealized conditions fail to capture the complexity of reaction mixtures in preparative organic synthesis.
Comment on "spontaneous breaking of permutation symmetry in pseudo-Hermitian quantum mechanics"
Comment on "spontaneous breaking of permutation symmetry in pseudo-Hermitian quantum mechanics"
Fernández, Francisco Marcelo
Li and Miao [Phys. Rev. A 85, 042110 (2012)PLRAAN1050-294710.1103/PhysRevA.85.042110] proposed a non-Hermitian Hamiltonian that is neither Hermitian nor PT symmetric but exhibits real eigenvalues for some values of the model parameters. In order to explain this fact, they resorted to PT-pseudo Hermiticity and to a so-called permutation symmetry. Here we show that the spectrum of this Hamiltonian can be easily analyzed in the usual way in terms of exact or broken antiunitary symmetries that appear to be more relevant than the permutation symmetry. In addition, we show why the authors' Hamiltonian and the well-known Pais-Uhlenbeck oscillator lead to the same fourth-order differential equation for the coordinates.
Leptospira species molecular epidemiology in the genomic era
Leptospira species molecular epidemiology in the genomic era
Caimi, Karina Cynthia; Repetto, Silvia; Varni, Vanina Delia; Ruybal, Paula
Leptospirosis is a zoonotic disease which global burden is increasing often related to climatic change. Hundreds of whole genome sequences from worldwide isolates of Leptospira spp. are available nowadays, together with online tools that permit to assign MLST sequence types (STs) directly from raw sequence data. In this work we have applied R7L-MLST to near 500 genomes and strains collection globally distributed. All 10 pathogenic species as well as intermediate were typed using this MLST scheme. The correlation observed between STs and serogroups in our previous work, is still satisfied with this higher dataset sustaining the implementation of MLST to assist serological classification as a complementary approach. Bayesian phylogenetic analysis of concatenated sequences from R7-MLST loci allowed us to resolve taxonomic inconsistencies but also showed that events such as recombination, gene conversion or lateral gene transfer played an important role in the evolution of Leptospira genus. Whole genome sequencing allows us to contribute with suitable epidemiologic information useful to apply in the design of control strategies and also in diagnostic methods for this illness.
Application of 1-Dimensional and 2-Dimensional Solid-State Nuclear Magnetic Resonance Spectroscopy to the Characterization of Morphine, Morphine Hydrochloride, and Their Hydrates
Application of 1-Dimensional and 2-Dimensional Solid-State Nuclear Magnetic Resonance Spectroscopy to the Characterization of Morphine, Morphine Hydrochloride, and Their Hydrates
Romañuk, Carolina Beatriz; Garro Linck, Yamila; Alves de Santana, M. Silmara; Manzo, Ruben Hilario; Ayala, Alejandro P.; Monti, Gustavo Alberto; Chattah, Ana Karina; Olivera, Maria Eugenia
The detailed knowledge of the solid forms of a drug is a key element in pharmaceutical development. Morphine (MOR) is an opiate alkaloid widely used to treat severe acute and chronic pain. Much of the available information on its solid state dates from several decades ago. In order to obtain updated and reliable information, 1-dimensional (1D) and 2-dimensional solid-state nuclear magnetic resonance spectroscopy were used and complemented with powder X-ray diffraction, FTIR, and Raman spectroscopy and thermal analysis. 13C cross-polarization with magic angle spinning 1D spectra accomplish a complete identification of the related forms of MOR. Remarkably, 1H-13C heteronuclear correlation spectra together with FTIR results gave clear evidence that neither MOR nor its hydrate crystallizes as a zwitterion. Our results indicate that the hydrogen bonds in the anhydrate forms have a different nature or strength than in their respective hydrates. The unique information obtained would be useful for the characterization of MOR as a bulk drug, dosage forms, and future developments.
Notions of the ergodic hierarchy for curved statistical manifolds
Notions of the ergodic hierarchy for curved statistical manifolds
Gomez, Ignacio Sebastián
We present an extension of the ergodic, mixing, and Bernoulli levels of the ergodic hierarchy for statistical models on curved manifolds, making use of elements of the information geometry. This extension focuses on the notion of statistical independence between the microscopical variables of the system. Moreover, we establish an intimately relationship between statistical models and families of probability distributions belonging to the canonical ensemble, which for the case of the quadratic Hamiltonian systems provides a closed form for the correlations between the microvariables in terms of the temperature of the heat bath as a power law. From this, we obtain an information geometric method for studying Hamiltonian dynamics in the canonical ensemble. We illustrate the results with two examples: a pair of interacting harmonic oscillators presenting phase transitions and the 2×2 Gaussian ensembles. In both examples the scalar curvature results a global indicator of the dynamics.
Calidad del agua de la Reserva Natural Urbana del Oeste (RNUO, Santa Fe) y su relación con biodiversidad del fitoplancton
Calidad del agua de la Reserva Natural Urbana del Oeste (RNUO, Santa Fe) y su relación con biodiversidad del fitoplancton
Vaschetto, P.A.; Polla, Wanda; Regaldo, Luciana María; Gervasio, Susana Graciela
Se estudió la calidad del agua de la Reserva Natural Urbana Oeste (RNUO) de Santa Fey su relación con la comunidad fitoplanctónica, que se encuentra en la base de las redes tróficas y actúa como estructuradora de los ecosistemas acuáticos. Los objetivos de este trabajo fueron: 1) relevar la diversidad del fitoplancton de la RNUO; 2) determinar la presencia de cianobacterias potencialmente tóxicas; 3) analizar la calidad del agua de los reservorios y compararla con niveles guía (NG); 4) establecer relaciones entre la calidad del agua y la comunidad fitoplanctónica para aportar información a emplear en futuros planes de manejo y de restauración de la RNUO. En cuatro sitios en otoño (OT1, 2, 3 y 4) y primavera (PR1, 2, 3 y 4) se registraron parámetros ambientales in situ y se tomaron muestras de agua para análisis de nutrientes, DQO, DBO, metales pesados (cromo, cobre, cadmio y plomo) y de sedimento para análisis de metales. Simultáneamente, se tomaron muestras de fitoplancton para análisis cuali-cuantitativo. La determinación taxonómica se realizó con claves específicas, se cuantificaron con microscopio invertido (método Utermöhl); se calculó su biovolumen (BVo), se analizó la diversidad específica según Shannon- Weavery se aplicó análisis de correlación de Spearman (p<0,05). En agua, el Cr superó los NG en OT1, OT2 y OT3; el Pb en OT1, OT2, PR1 y PR3; el Cu en OT4. En sedimento, el Cr superó los NG en PR1 y PR2. Los valores de DBO indicaron que los sitios estudiados corresponden a ambientes meso y oligosaprobios. La densidad mínima se registró en OT3 y PR3, la máxima en PR4. En PR la riqueza fue menor, aunque se registró un incremento de la densidad en coincidencia con el aumento de nutrientes (NO3 -, PO4). Las Chlorophyceae y Bacillariophyceae fueron dominantes en OT y PR, respectivamente. Se observó una correlación negativa y significativa entre la riqueza de especies y la temperatura, entre el BVo de Bacillariophyceae con el NH4 + y con la transparencia. Se observó una correlación positiva y significativa entre el BVo de Bacillariophyceae y Cyanobacteria con la temperatura. Se determinaron 3 spp. de cianobacterias potencialmente tóxicas, Anabaenopsis elenkinii, Raphidiopsis curvata y R. mediterranea. El género Raphidiopsis presentó una correlación positiva con el NH4 + y negativa con NO3 -. Este trabajo brinda información relevante sobre la calidad ambiental de los reservorios de la RNUO tomando a la comunidad fitoplanctónica como bioindicadora de salud ecosistémica.
An Ethnoarchaeological Study on Anthropic Markers from a Shell-midden in Tierra del Fuego (Southern Argentina): Lanashuaia II
An Ethnoarchaeological Study on Anthropic Markers from a Shell-midden in Tierra del Fuego (Southern Argentina): Lanashuaia II
Zurro Hernández, Débora; Negre Pérez, Joan; Ruiz Pérez, Javier; Alvarez, Myrian Rosa; Briz Godino, Ivan; Caro, Jorge
For many years the identification of activity areas has been carried out through the spatial distribution of lithics, zooarchaeological remains and specific features such as fireplaces. However, these data are rarely combined and integrated with results from specific analytical techniques such as phytoliths, organic matter, carbonates and multielemental analysis. This research presents the first results of an intrasite spatial analysis on a layer from the site Lanashuaia II, a shell-midden located on the Beagle Channel coast (Tierra del Fuego, Argentina). Ethnoarchaeology is used as a methodological tool to give content to the concept of anthropic markers by means of formulating archaeological hypothesis on the basis of ethnological information. This paper presents the application of specific anthropic markers, which have been designed and applied to identify ashy remains and waste areas through different combinations of proxies. The results show how an approach that integrates different techniques enhances data interpretation and allows to give visibility to activities that may not leave visible evidences.
A comparative study of Three–Phase Dual Active Bridge Converters for renewable energy applications
A comparative study of Three–Phase Dual Active Bridge Converters for renewable energy applications
Núñez, Rubén Orlando; Oggier, German Gustavo; Botterón, Fernando; Garcia, Guillermo
The influence of different transformers in the operation of a three–phase dual active bridges DC–DC converter is analyzed. The transformers considered have their windings connected in star–star, delta–delta, star–delta and delta–star. The main objective of this paper is to obtain factors of merits to allow the selection of a transformer which will yield higher converter performance for a given application. These factors of merits allows estimate the losses in power semiconductors and high frequency transformers. Additionally, operation regions under soft switching are deduced for each transformer.
À la recherche d’importations européennes dans les peintures de paysage de la région de Córdoba (Argentine) au début du xx siècle
À la recherche d’importations européennes dans les peintures de paysage de la région de Córdoba (Argentine) au début du xx siècle; In search of European introductions in the landscapes near Córdoba (Argentina) at the beginning of the XXth century
Metzger, Alexis; Tabeaud, Martine; Mafferra, Luis Eduardo; Marconetto, María Bernarda
En la provincia de Córdoba (centro de la Argentina) durante la primer mitad del siglo XX, los pintores presentan especies vegetales europeas. Estos elementos del paisaje, muestran una mixtura entre lo local y lo venido de afuera. Los migrantes importaron sus imaginarios paisajísticos europeos que van a reproducir en su nuevo hogar. Los indicadores de estas transformaciones en el paisaje observadas en las pinturas fueron cruzadas con otros testimonios contemporáneos.; Dans la région de Córdoba (centre de l’Argentine) durant la première moitié du XXe siècle, les peintres montrent des espèces végétales venues d’Europe. Ces éléments du paysage participent d’un mixte entre ce qui est argentin et ce qui vient d’ailleurs. Car les migrants qui ont importé leurs imaginaires paysagers européens vont s’attacher à les reproduire dans leur nouvelle patrie. Les indices de ces transformations paysagères fournis par les peintures seront croisés avec des témoignages de contemporains.; In the Córdoba area in Central Argentina during the first half of the XXth century, painters show vegetal species coming from Europe. Those landscape elements are part of a mixt between what is argentine and what comes from elsewhere. The emigrants with their European mental pictures apply themselves to recreate them in their new world. The indication of landscape transformations in the works of art will be pointed out under the light of contemporary testimonies.
Las políticas científicas recientes en las universidades nacionales
Las políticas científicas recientes en las universidades nacionales
Unzué, Martín; Rovelli, Laura Ines
El presente trabajo enseña un análisis panorámico de dos políticas científicas implementadas en Argentina durante el período 2004-2015 y propone indagar su incidencia en el plano de las universidades nacionales. En primer lugar, se estudiaron los alcances de la política de formación de doctores con su influencia en la configuración reciente del posgrado y de la carrera docente en la universidad pública. Luego se examinó el influjo de la política de priorización de la investigación científica en las estrategias y orientaciones de los dispositivos universitarios de promoción de la investigación...
Study of the effects of spray drying in whey-starch on the probiotic capacity of Lactobacillus rhamnosus 64 in the gut of mice
Study of the effects of spray drying in whey-starch on the probiotic capacity of Lactobacillus rhamnosus 64 in the gut of mice
Lavari, Luisina; Burns, Patricia Graciela; Páez, R.; Reinheimer, Jorge Alberto; Vinderola, Celso Gabriel
Aims: To evaluate the effects of spray drying of Lactobacillus rhamnosus 64 on its capacity to modulate the gut immune response and on the attenuation of TNBS-induced colitis in mice. Methods and Results: Lactobacillus rhamnosus 64 was spray dried in cheese whey-starch solution and administered to mice for 3, 6 or 10 consecutive days. Peritoneal macrophage phagocytic activity, secretory IgA levels in the small intestinal fluid and TNFα, IFNγ, IL-10, IL-6 and IL-2 levels in homogenates of the small and large intestine were determined. The effects of spray drying were also evaluated in an acute model of Trinitrobenzenesulfonic acid (TNBS)-induced colitis. A shift in the regulation of immune parameters, particularly the cytokine profile, was observed for mice treated with the spray-dried culture, compared to the profile observed in animals that received the strain as fresh culture (FC). The spray-dried culture of L. rhamnosus 64 showed anti-inflammatory properties in murine model of TNBS-induced colitis. Conclusions: The spray-drying process of L. rhamnosus 64 in whey-starch modified its immunomodulating capacity in healthy animals and conferred enhanced protection in an in vivo model of inflammation. Significance and Impact of the Study: Probiotic capacity can be affected by spray drying in relation to the properties observed for the strain as an overnight FC. This fact should be taken into account when producing the culture for its application in the industry.
Correlation between in vitro and in vivo assays in selection of probiotics from traditional species of bacteria
Correlation between in vitro and in vivo assays in selection of probiotics from traditional species of bacteria
Vinderola, Celso Gabriel; Gueimonde, Miguel; Gomez-Gallego, Carlos; Delfederico, Lucrecia; Salminen, Seppo
Background In vitro selection tests such as exposure to low pH and bile salts, competitive exclusion of pathogens, adherence to cell lines and prokaryotic-eukaryotic co-cultures have been commonly used to predict the functional properties of lactobacilli and bifidobacteria for their use as probiotics. However, the correlation of in vitro results with in vivo performance remains obscure. Scope and approach To review the current state of evidence linking in vitro predictions to in vivo outcomes in selecting probiotic candidates and to discuss the advantages and limitations of the various assays presently available. Key findings and conclusions The successful use of lactobacilli and bifidobacteria as traditional probiotics is based on their occurrence in human milk, naturally fermented foods, in the gastrointestinal tract and feces of infants and adults as well as on their culturability, technological robustness and long history of safe use. The lack of standardized protocols for in vitro and in vivo studies hampers comparison of the potential of new species and strains. There is thus a need to conduct selection of potential probiotics in a more robust manner and to focus well-defined in vitro and in vivo studies to document health benefits.
Interpretable interval type-2 fuzzy predicates for data clustering: A new automatic generation method based on self-organizing maps
Interpretable interval type-2 fuzzy predicates for data clustering: A new automatic generation method based on self-organizing maps
Comas, Diego Sebastián; Pastore, Juan Ignacio; Bouchet, Agustina; Ballarin, Virginia Laura; Meschino, Gustavo Javier
In previous works, we proposed two methods for data clustering based on automatically discovered fuzzy predicates which were referred to as SOM-based Fuzzy Predicate Clustering (SFPC) [Meschino et al., Neurocomputing, 147, 47–59 (2015)] and Type-2 Data-based Fuzzy Predicate Clustering (T2-DFPC) [Comas et al., Expert Syst. Appl., 68, 136–150 (2017)]. In such methods, fuzzy predicates allow both data clustering and knowledge discovering about the obtained clusters. This last feature constitutes novelty comparing to other existing approaches and it is a major contribution in the data clustering field. Based on these previous methods, in the present paper a new automatic clustering method based on fuzzy predicates is proposed which uses Self-Organizing Maps (SOMs) and is called Type-2 SOM-based Fuzzy Predicate Clustering (T2-SFPC). The new method does not require any prior knowledge about the clustering addressed. First, a random partition is defined on the dataset to be clustered and SOMs are configured and trained using the resulting data subsets. Second, an automatic clustering approach is applied on the SOM codebooks, discovering representative data of the different clusters, which are called cluster prototypes. Third, interval type-2 membership function formed by Gaussian-shape sub-functions and fuzzy predicates are defined, allowing data clustering and its interpretation. The proposed method preserves all the advantages of the previous methods SFPC and T2-DFPC in relation to the knowledge extraction capabilities and their potential application on distributed clustering and parallel computing, but results obtained on several public datasets tested showed more compactness and separation of the clusters defined by the T2-SFPC, outperforming both the previous methods and the several classical clustering approaches tested, considering internal and external validation indices. Additionally, both clustering interpretation and optimization capabilities are improved by the proposed method when compared to the methods SFPC and T2-DFPC.
Los ambientes acuáticos en arqueología
Los ambientes acuáticos en arqueología
Prates, Luciano Raúl; Bonomo, Mariano
En este trabajo se discute sobre la importancia de los ambientes acuáticos para el estudio del pasado en arqueología. Aunque el tema es abordado de modo global, el énfasis está puesto en sociedades con economías basadas en la caza, la recolección, la pesca y la horticultura a pequeña escala, y se ilustran con ejemplos arqueológicos mayoritariamente regionales de nuestro país y Sudamérica. El concepto de ambiente acuático es considerado en su sentido amplio, en el que se incluyen los ambientes marinos y del interior continental, de aguas quietas y de aguas corrientes, someras y profundas. Luego de una síntesis sobre el uso de los ambientes acuáticos a lo largo de la historia de la humanidad, el trabajo se enfoca en tres temas principales. Primero, en los modos y estrategias tecnológicas de explotación de los ambientes acuáticos (navegación, uso del agua, y explotación de minerales, plantas y animales). Luego, en los distintos grados de intensidad con que las sociedades humanas hicieron uso de estos entornos, para lo cual se definen y caracterizan cuatro modalidades principales (uso puntual, uso ocasional, uso sostenido y uso intensivo), se derivan algunas expectativas arqueológicas y se puntualizan algunos ejemplos. Por último, se resumen los aspectos principales de la relación entre los ambientes acuáticos y la comunicación y el simbolismo de las sociedades.; In this article we discuss the importance of aquatic environments for past societies, and the ways in which this topic has been approached in archaeological research. Although framed at a global scale, the focus is on hunter-gatherer, fisher, and/or smallscale horticulture societies, with special emphasis on Argentina and Southern South America. Aquatic environments are considered here in their broadest sense, including both marine and continental lands, and also still/moving, and shallow/deep bodies of water. After a general summary on the importance of aquatic environments throughout human history, this article focuses on three main topics. First, the different ways, and technological strategies in which humans exploit aquatic landscapes (navigation, use of water, and exploitation of mineral, animal and plant resources). Following, the differences in the use intensity of aquatic environments by humans; in order to categorize this diversity four different variants were defined (punctual use, occasional use, sustained use, and intensive use) for each of which archaeological expectations were defined. Finally, we also review certain relevant aspects connecting aquatic environments to social communication and symbolism.
Combinación de hongos movilizadores y solubilizadores de fósforo con rocas fosfóricas y materiales volcánicos para la promoción del crecimiento de plantas de lechuga (Lactuca sativa L.)
Combinación de hongos movilizadores y solubilizadores de fósforo con rocas fosfóricas y materiales volcánicos para la promoción del crecimiento de plantas de lechuga (Lactuca sativa L.); Combination of phosphorus solubilizing and mobilizing fungi with phosphate rocks and volcanic materials to promote plant growth of lettuce (Lactuca sativa L.)
Velázquez, María Silvana; Cabello, Marta Noemí; Eliades, Lorena Alejandra; Russo, Maria Leticia; Allegrucci, Natalia; Schalamuk, Santiago
Los hongos formadores de micorrizas arbusculares (HFMA)incrementan la toma de fosfatos solubles, mientras que los hongossolubilizadores de P (HSP) promueven la solubilización de complejosinsolubles de fosfato, beneficiando la nutrición de las plantas. Otraalternativa para mantener la productividad de los cultivos es lacombinación de minerales o rocas que aporten nutrientes entre otraspropiedades deseables. El objetivo de este trabajo fue combinar HFMA yHSP con materiales piroclásticos (cenizas y pumicitas) del Volcán Puyehuey rocas fosfóricas (RP) del Grupo Río Chico (Chubut)- en la elaboraciónde un sustrato para la producción en maceta de Lactuca sativa. Paraformular los sustratos se utilizó una mezcla de Terrafertil® : ceniza.Penicillium thomii fue el HSP y esporas de Rhizophagus intraradices(HFMA) (AEGIS® Irriga). Los tratamientos fueron: 1) Sustrato 2) Sustrato+ HFMA 3) Sustrato + HSP 4) Sustrato + HFMA + HSP 5) Sustrato: RP 6)Sustrato: RP + HFMA 7) Sustrato: RP + HSP y 8) Sustrato: RP + HFMA + HSP.Se efectuaron 3 repeticiones por tratamiento. Todos los parámetrosevaluados: contenidos de P total y asimilable en sustrato, P en tejido ybiomasa seca vegetal fueron significativamente mayores en las plantas quecrecieron en el sustrato con RP, HPS y HFMA. Este trabajo confirma que lacombinación HSP/HFMA con cenizas volcánicas del Puyehue y las RP delGrupo Río Chico formuladas con un sustrato comercial promueven elcrecimiento de L. sativa, incrementando de este modo el valor agregado degeomateriales de origen nacional.; Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote solubilization of insoluble phosphates complexes, favoring plant nutrition. Another alternative to maintaining crop productivity is to combine minerals and rocks that provide nutrients and other desirable properties. The aim of this work was to combine AMF and S with pyroclastic materials (ashes and pumices) from Puyehue volcano and phosphate rocks (PR) from Rio Chico Group (Chubut) - to formulate a substrate for the production of potted Lactuca sativa. A mixture of Terrafertil®:ashes was used as substrate. Penicillium thomii was the solubilizing fungus and Rhizophagus intraradices spores (AMF) was the P mobilizer (AEGIS® Irriga). The treatments were: 1) Substrate; 2) Substrate + AMF; 3) Substrate + S; 4) Substrate + AMF + S; 5) Substrate: PR; 6) Substrate: PR + AMF; 7) Substrate: PR + S and 8) Substrate: PR + AMF + S. Three replicates were performed per treatment. All parameters evaluated (total and assimilable P content in substrate, P in plant tissue and plant dry biomass) were significantly higher in plants grown in substrate containing PR and inoculas with S and AMF. This work confirms that the combination of S/AMF with Puyehue volcanic ashes, PR from the Río Chico Group and a commercial substrate promote the growth of L. sativa, thus increasing the added value of national geomaterials.
Transport Properties of Co in Cu(100) from Density Functional Theory Calculations
Transport Properties of Co in Cu(100) from Density Functional Theory Calculations
García Fernández, Carlos; Abufager, Paula Natalia; Lorente Palacios, Nicolas
The electronic transport properties of a point-contact system formed by a single Co atom adsorbed on Cu (100) and contacted by a copper tip is evaluated in the presence of intra-atomic Coulomb interactions and spin-orbit coupling. The calculations are performed using equilibrium Green's functions evaluated within density functional theory completed with a Hubbard U term and spin-orbit interaction, as implemented in the Gollum package. We show that the contribution to the transmission between electrodes of spin-flip components is negative and scaling as λ2/Δ2 where λ is the SOC and Δ the Co atom-electrode coupling. Hence, due to this unfavorable ratio, SOC effects in transport in this system are small. However, we show that the spin-flip transmission component can increase by 2 orders of magnitude depending on the value of the Hubbard U term. These effects are particularly important in the contact regime because of the prevalence of d-electron transport, while in the tunneling regime, transport is controlled by the sp-electron transmission, and results are less dependent on the values of U and SOC. Using our electronic structure and the elastic transmission calculations, we discuss the effect of U and SOC on the well-known Kondo effect of this system.
l-Hemi-Implicative Semilattices
l-Hemi-Implicative Semilattices
Castiglioni, José Luis; San Martín, Hernán Javier
An l-hemi-implicative semilattice is an algebra A=(A,∧,→,1) such that (A,∧,1) is a semilattice with a greatest element 1 and satisfies: (1) for every a,b,c∈A , a≤b→c implies a∧b≤c and (2) a→a=1 . An l-hemi-implicative semilattice is commutative if if it satisfies that a→b=b→a for every a,b∈A . It is shown that the class of l-hemi-implicative semilattices is a variety. These algebras provide a general framework for the study of different algebras of interest in algebraic logic. In any l-hemi-implicative semilattice it is possible to define an derived operation by a∼b:=(a→b)∧(b→a) . Endowing (A,∧,1) with the binary operation ∼ the algebra (A,∧,∼,1) results an l-hemi-implicative semilattice, which also satisfies the identity a∼b=b∼a . In this article, we characterize the (derived) commutative l-hemi-implicative semilattices. We also provide many new examples of l-hemi-implicative semilattice on any semillatice with greatest element (possibly with bottom). Finally, we characterize congruences on the classes of l-hemi-implicative semilattices introduced earlier and we characterize the principal congruences of l-hemi-implicative semilattices.
INGAP-PP effects on β-cell mass and function are related to its positive effect on islet angiogenesis and VEGFA production
INGAP-PP effects on β-cell mass and function are related to its positive effect on islet angiogenesis and VEGFA production
Román, Carolina Lisi; Maiztegui, Barbara; del Zotto, Hector Herminio; Gagliardino, Juan Jose; Flores, Luis Emilio
Our aim was to determine whether islet angiogenesis and VEGFA production/release participate in the mechanism by which INGAP-PP enhances β-cell function and mass. We used two models: a) in vivo (normal rats injected with INGAP-PP for 10 days) and b) in vitro (normal islets cultured for 4 days with INGAP-PP, VEGFA, Rapamycin, and the specific VEGF-Receptor inhibitor, SU5416). INGAP-PP administration enhanced insulin secretion, β-cell mass, islet vascularization, and angiogenesis without affecting glucose homeostasis. Normal islets cultured with INGAP-PP and VEGFA increased insulin and VEGFA secretion while apoptosis decreased. INGAP-PP-induced effects were prevented by both Rapamycin and SU5416. INGAP-PP effects on β-cell mass and function were significantly associated with a positive effect on islet angiogenesis and VEGFA production/release. VEGF-A possibly potentiates INGAP-PP effect through mTORC pathway.
Depressive symptoms and the role of affective temperament in adults with attention-deficit/hyperactivity disorder (ADHD): A comparison with bipolar disorder
Depressive symptoms and the role of affective temperament in adults with attention-deficit/hyperactivity disorder (ADHD): A comparison with bipolar disorder
Torrente, Fernando; López, Pablo; Lischinsky, Alicia; Cetkovich Bakmas, Marcelo; Manes, Facundo Francisco
Objectives: To investigate the characteristics of depressive symptoms and the influence of affective temperament in adults with attention-deficit/hyperactivity disorder (ADHD), in comparison with bipolar disorder (BD) patients and healthy controls (HCs). Method: Sixty patients with ADHD, 50 patients with BD, and 30 HCs were assessed with instruments for measuring depressive symptoms (Beck Depression Inventory-II), and affective temperaments (Temperament Scale of Memphis, Pisa and San Diego, self-administered version; TEMPS-A). In addition, participants were evaluated with scales for measuring ADHD symptoms, impulsiveness, anxiety, executive dysfunction, and quality of life. Results: ADHD patients showed levels of depressive symptoms similar to BD patients and higher than HCs. Only neurovegetative symptoms of depression differentiated ADHD and BD groups (BD > ADHD). Depressive symptoms in ADHD patients correlated positively with core ADHD, impulsivity, anxiety, and dysexecutive symptoms and negatively with quality of life. Thirty-eight percent of patients with ADHD scored above the cutoff for at least one affective temperament. Cyclothymic was the more common affective temperament (25%). ADHD patients with affective temperamental traits were more depressed and impulsive than patients without those traits and showed a symptomatic profile analogous to BD patients. Limitations: The small size of resultant samples when ADHD group was stratified by the presence of affective temperament. In addition, results may not generalize to less severe ADHD patients from the community. Conclusions: Concomitant depressive symptoms constitute a common occurrence in adults with ADHD that carries significant psychopathological and functional consequences. The concept of affective temperaments may be an interesting link for explaining depressive symptomatology and emotional impulsivity in a subgroup of patients with ADHD, beyond the classic idea of comorbidity.
Studies on lignin extraction from rice husk by a soda-ethanol treatment: kinetics, separation, and characterization of products
Studies on lignin extraction from rice husk by a soda-ethanol treatment: kinetics, separation, and characterization of products
Dagnino, Eliana Paola; Felissia, Fernando Esteban; Chamorro, Ester Ramona; Area, Maria Cristina
The delignification kinetics of lignocellulosic waste is an important tool for the study of the technical-economic viability of biorefinery processes. The aim of this work was to study the kinetic of lignin extraction by a soda-ethanol treatment of hemicelluloses-free rice husk, within the framework of a biorefinery. Additionally, the type of phenolic structures in the extracted lignin and the behavior of inorganics were evaluated. The kinetic study was carried out at 140, 150, and 160 °C, at different times between 3 and 100 min of reaction for each temperature. A first order kinetic model was adjusted to the experimental data of residual lignin in the treated solid in the fast and slow phase. The kinetic constant k0 varied from 0.021 to 0.035min-1 for 140 to 160 °C. The activation energies were 38.59 KJ/mol and 33.47KJ/mol for the fast and slow phase, respectively. The inorganics components remained in the solid and the proportion of silicon increased through all treatments. About 50% of the initial lignin with 1% of inorganics was recovered by precipitation. The percentage of total OH in lignin remained high, about 8.5%, and decreased with the temperature but not with the time of the reaction.
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