CONICET Digital

Dark-soliton collisions in a toroidal Bose-Einstein condensate

Dark-soliton collisions in a toroidal Bose-Einstein condensate Jezek, Dora Marta; Capuzzi, Pablo; Cataldo, Horacio Maximo We study the dynamics of two gray solitons in a Bose-Einstein condensate confined by a toroidal trap with a tight confinement in the radial direction. Gross-Pitaevskii simulations show that solitons can be long-living objects passing through many collisional processes. We have observed quite different behaviors depending on the soliton velocity. Very slow solitons, obtained by perturbing the stationary solitonic profile, move with a constant angular velocity until they collide elastically and move in the opposite direction without showing any sign of lowering their energy. In this case the density notches are always well separated and the fronts are sharp and straight. Faster solitons present vortices around the notches, which play a central role during the collisions. We have found that in these processes the solitons lose energy, as the outgoing velocity turns out to be larger than the incoming one. To study the dynamics, we model the gray soliton state with a free parameter that is related to the soliton velocity. We further analyze the energy, soliton velocity, and turning points in terms of such a free parameter, finding that the main features are in accordance with the infinite one-dimensional system.

Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae)

Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae) Barrionuevo, Jose Sebastian The most common feeding mechanism among aquatic vertebrates as fishes, turtles, and salamanders is inertial suction. However, among the more than 6,400 species of anurans, suction feeding occurs only in pipids. Pipidae is a small basal lineage relative to Neobatrachia, an enormous clade that contains about 96% of extant anurans. The Andean neobatrachian frogs of the genus Telmatobius include strictly aquatic and semiaquatic species. Diet analyses indicate that some species of Telmatobius feed on strictly aquatic prey, but until now their feeding mechanisms have been unknown. Herein, the feeding mechanisms in two species of Telmatobius, that represent the two predominant modes of life in the genus, are explored. The semiaquatic T. oxycephalus and the fully aquatic T. rubigo are studied using high-speed cinematography and standard anatomical techniques to provide a qualitative approach to feeding behavior and a detailed morphological description of the mouth, tongue, hyoid and related muscles. T. oxycephalus uses similar mechanisms of aquatic prey capture as do the vast majority of anurans that are capable of forage in water, whereas the fully aquatic T. rubigo is an inertial suction feeder. This is the first report of an objective record of this unique feeding behavior in a Neobatrachian. Several morphological characters seem to be related with this function and are convergent with those of pipids.

Acquired TERT promoter mutations activate TERT expression in mantle cell lymphoma

Acquired TERT promoter mutations activate TERT expression in mantle cell lymphoma Panero, Julieta; Alves Paiva, Raquel; Roisman, Alejandro; Santana Lemos, Barbara; Falcao, Roberto P.; Oliveira, Gustavo; Martins, Diego; Stanganelli, Carmen Graciela; Slavutsky, Irma Rosa; Calado, Rodrigo Mantle cell lymphoma (MCL) is an aggressive lymphoid neoplasm with poor prognosis. Acquired telomerasereverse transcriptase gene promoter (TERTp) mutations are among the most frequent somatic non-codingmutations in cancers. In this study, the prevalence of TERTp mutations in 24 MCL and 21 other lymphoidneoplasias (oLN) was investigated. Eight MCL samples (33%) carried TERTp mutations, two homozygous andsix heterozygous (seven C228T and one C250T), which directly correlated with higher TERT transcription,mitochondrial DNA copy number, and IGHV mutational status in MCL neoplastic cells. TERTp mutations werenot found in oLN. TERTp mutations correlated with more lymphoma proliferation and tumor burden, assuggested by the higher number of lymphoma cells circulating in peripheral blood, and tended to associatewith longer MCL telomeres, especially in homozygous mutants, although not statistically significant.Telomere-biology genes were overexpressed in MCL cells in comparison to healthy lymphocytes, but werenot influenced by mutation status. The findings described for the first time that acquired TERTp mutationsare common in MCL but not in other lymphoid neoplasms. It was also demonstrated that TERTp mutationsassociated with higher TERT mRNA expression in MCL cells in vivo and higher tumor burden, suggestingthese mutations as a driver event in MCL development and progression.

Soluble RANKL production by leukemic cells in a case of chronic lymphocytic leukemia with bone destruction

Soluble RANKL production by leukemic cells in a case of chronic lymphocytic leukemia with bone destruction Borge, Mercedes; Delpino, María Victoria; Podaza, Enrique Arturo; Stanganelli, Carmen Graciela; Palau Nagore, Maria Virginia; Roisman, Alejandro; Slavutsky, Irma Rosa; Palacios, Maria F.; Ledesma, Ignacio; Arra, Antonio; Diaz, Alicia; Giordano, Mirta Nilda; Gamberale, Romina; Bezares, Raimundo F. Receptor Activator for Nuclear Factor j B Ligand(RANKL) is a member of the TNF-a superfamily normallyproduced by osteoblasts and stromal cells, whichactivates its receptor RANK present on osteoclasts andosteoclast precursors, thus favoring their differentiationand activity. An aberrant expression of RANKL was previouslyreported in a proportion of B cell malignanciessuch as Chronic lymphocytic leukemia (CLL), multiplemyeloma (MM) and follicular lymphoma

Physiological and genetic differences amongst Rhodococcus species for using glycerol as a source for growth and triacylglycerol production

Physiological and genetic differences amongst Rhodococcus species for using glycerol as a source for growth and triacylglycerol production Herrero, Ornella Marisa; Moncalián, Gabriel; Alvarez, Hector Manuel We analysed the ability of five different rhodococcal species to grow and produce triacylglycerols (TAGs) from glycerol, the main byproduct of biodiesel production. Rhodococcus fascians and Rhodococcus erythropolis grew fast on glycerol, whereas Rhodococcus opacus and Rhodococcus jostii exhibited a prolonged lag phase of several days before growing. Rhodococcus equi only exhibited poor growth on glycerol. R. erythropolis DSMZ 43060 and R. fascians F7 produced 3.9–4.3 g cell biomass l− 1 and 28.4–44.6 % cellular dry weight (CDW) of TAGs after 6 days of incubation; whereas R. opacus PD630 and R. jostii RHA1 produced 2.5–3.8 g cell biomass l− 1 and 28.3–38.4 % CDW of TAGs after 17 days of growth on glycerol. Genomic analyses revealed two different sets of genes for glycerol uptake and degradation (here named clusters 1 and 2) amongst rhodococci. Those species that possessed cluster 1 (glpFK1D1) (R. fascians and R. erythropolis) exhibited fast growth and lipid accumulation, whereas those that possessed cluster 2 (glpK2D2) (R. opacus, R. jostii and R. equi) exhibited delayed growth and lipid accumulation during cultivation on glycerol. Three glycerol-negative strains were complemented for their ability to grow and produce TAGs by heterologous expression of glpK2 from R. opacus PD630. In addition, we significantly reduced the extension of the lag phase and improved glycerol assimilation and oil production of R. opacus PD630 when expressing glpK1D1 from R. fascians. The results demonstrated that rhodococci are a flexible and amenable biological system for further biotechnological applications based on the reutilization of glycerol.

Human Microbiota of the Argentine Population- A pilot study

Human Microbiota of the Argentine Population- A pilot study Carbonetto, María Belén; Fabbro Frías, Mónica Carolina; Sciara, Mariela Ines; Serevalle, Analia; Mejico, Guadalupe; Revale, Santiago; Romero, Soledad; Brun, Bianca; Fay, Marcelo; Fay, Fabian; Vazquez, Martin Pablo The human microbiota is the collection of microorganisms living in or on the human body. An imbalance or dysbiosis in these microbial communities can be associated with a wide variety of human diseases (Petersen and Round, 2014; Pham and Lawley, 2014; Zaura et al., 2014). Moreover, when the microbiota of the same body sites is compared between different healthy individuals, specific microbial community features are apparent (Li et al., 2012; Yatsunenko et al., 2012; Oh et al., 2014; Relman, 2015). In addition, specific selective pressures are found at distinct body sites leading to different patterns in microbial community structure and composition (Costello et al., 2009; Consortium, 2012b; Zhou et al., 2013). Because of these natural variations, a comprehensive characterization of the healthy microbiota is critical for predicting alterations related to diseases. This characterization should be based on a broad healthy population over time, geography, and culture (Yatsunenko et al., 2012; Shetty et al., 2013; Leung et al., 2015; Ross et al., 2015). The study of healthy individuals representing different ages, cultural traditions, and ethnic origins will enable to understand how the associated microbiota varies between populations and respond to different lifestyles. It is important to address these natural variations in order to later detect variations related to disease.

Taxonomy of the Phyllotis osilae species group in Argentina; the status of the “Rata de los nogales” (Phyllotis nogalaris Thomas, 1921; Rodentia: Cricetidae)

Taxonomy of the Phyllotis osilae species group in Argentina; the status of the “Rata de los nogales” (Phyllotis nogalaris Thomas, 1921; Rodentia: Cricetidae) Jayat, Jorge Pablo; Ortiz, Pablo Edmundo; Gonzalez, Francisco Rodrigo; D'elía, Guillermo The taxonomic status of populations of the genus Phyllotis from northwestern Argentina (NWA) has undergone recent changes, with the addition of two species (P. alisosiensis and P. anitae) to the traditionally recognized forms (P. caprinus, P. xanthopygus, and P. osilae). Three of these species (P. anitae, P. osilae, and P. alisosiensis) were included within the Phyllotis osilae species group. Most authors recognized three subspecies of P. osilae for NWA: P. osilae osilae, P. o. nogalaris, and P. o. tucumanus. Morphological, morphometric, and molecular studies based on recently collected specimens suggest that current classification does not reflect the diversity of this group in NWA, revealing the need of some taxonomic reallocations and new distributional delimitations. Here we propose that P. nogalaris must be recognized as a valid species and the restriction of P. osilae to southern Peru and central Bolivia. Following our results, we expect an outstanding improvement in the taxonomic knowledge of the Phyllotis osilae species group in the coming years.

Action of fosetyl‐al and metalaxyl against Phytophthora austrocedri

Action of fosetyl‐al and metalaxyl against Phytophthora austrocedri Silva, Patricia Valeria; Vélez, María Laura; Hernández Otaño, D.; Nuñez, C.; Greslebin, Alina Gabriela Fosetyl‐Al and metalaxyl, the most commonly used systemic fungicides against Phytophthora, were evaluated for their efficacy to control Phytophthora austrocedri, the pathogen that causes a serious disease at the Austrocedrus chilensis forests in Patagonia. The effect of the chemicals on pathogen development in vitro and in planta was analysed. Both chemicals were shown to protect plants from the pathogen. In vitro assays showed that asexual reproduction was sensitive to both chemicals. However, mycelial growth and sexual reproduction, which were clearly sensitive to metalaxyl, were sensitive only to high concentrations of fosetyl‐Al. Fosetyl‐Al and metalaxyl had almost the same efficacy when applied preventively by soil drench to seedlings. This difference between in vitro and in planta results can be attributed to the dual action of fosetyl‐Al, not only inhibiting the pathogen but also stimulating host defence. In adult trees, preventive and curative treatments were tested, but only the fosetyl‐Al preventive treatment was effective in the assayed conditions. Interestingly, seedlings pretreated with both fungicides were less susceptible to the effectors secreted by the pathogen. Our results indicate that fosetyl‐Al and metalaxyl provide some resistance to the plant besides the fungistatic direct action on the pathogen. Further studies to elucidate a possible resistance‐inducing activity of these chemicals and the mechanisms involved are underway.

Melatonin-Induced Oncostasis, Mechanisms and Clinical Relevance

Melatonin-Induced Oncostasis, Mechanisms and Clinical Relevance Cardinali, Daniel Pedro; Escames, Germaine; Acuña Castroviejo, Darío; Ortiz, Francisco; Fernández Gil, Beatriz; Guerra Librero, Ana; García López, Sergio; Shen, Ying; Florido, Javier Melatonin is a natural substance ubiquitously distributed and present in almost all living species, from unicellular organisms to humans. Melatonin is synthesized not only in the pineal gland but also in most tissues in the body where it may have a cytoprotective function via paracrine or autocrine effects. Melatonin is effective in suppressing neoplastic growth in a variety of tumors. The mechanisms involved include antiproliferative effects via modulation of cell cycle, ability to induce apoptosis in cancer cells, anti-angiogenic and antimetastatic effects, anti-estrogenic activity, the capacity to decrease telomerase activity, immune modulation, and direct and indirect antioxidant effects. Besides these oncostatic properties, melatonin deserves to be considered in the treatment of cancer for two other reasons. First, because its hypnotic-chronobiotic properties, melatonin use that can allow the clinician to effectively address sleep disturbances, a major co-morbidity in cancer. Second, because melatonin’s anxiolytic and antidepressant effects, it has a possible application in two other major co-morbidities seen in cancer patients, i.e. depression and anxiety. This report summarizes the possible mechanisms involved in melatonin oncostasis and reviews what is known about the clinical application of melatonin as an adjuvant therapy in cancer patients.

Thalidomide analogues: Tumor necrosis factor-alpha inhibitors and their evaluation as anti-inflammatory agents

Thalidomide analogues: Tumor necrosis factor-alpha inhibitors and their evaluation as anti-inflammatory agents Casal, Juan José; Bollini, Mariela; Lombardo, Maria Elisa; Bruno, Ana María A series of related thalidomide derivatives (2-9) were synthesized by microwave irradiation and evaluated for anti-inflammatory activity. Such activity was assessed in vivo and ex vivo. Compounds 2, 8 and 9 showed the highest levels of inhibition of TNF-α production. On rat paw edema and hyperalgesia assays, compound 9, (1,4-phthalazinedione) demonstrated the highest in vivo anti-inflammatory activity. Thus, compound 9 can be considered as a promising compound to be subjected to further modification to obtain new agents for the treatment of inflammatory diseases.

The AIMSS Project, III : the stellar populations of compact stellar systems

The AIMSS Project, III : the stellar populations of compact stellar systems Janz, Joachin; Norris, Mark A.; Forbes, Duncan A.; Huxor, Avon; Romanowsky, Aaron; Frank, Matthias; Escudero, Carlos Gabriel; Faifer, Favio Raúl; Forte, Juan Carlos; Kannappan, Sheila J.; Maraston, Claudia; Brodie, Jean; Strader, Jay; Thompson, Bradley In recent years, a growing zoo of compact stellar systems (CSSs) have been found whose physical properties (mass, size, velocity dispersion) place them between classical globular clusters (GCs) and true galaxies, leading to debates about their nature. Here we present results using a so far underutilized discriminant, their stellar population properties. Based on new spectroscopy from 8-10m telescopes, we derive ages, metallicities, and [α/Fe] of 29 CSSs. These range from GCs with sizes of merely a few parsec to compact ellipticals (cEs) larger than M32. Together with a literature compilation, this provides a panoramic view of the stellar population characteristics of early-type systems. We find that the CSSs are predominantly more metal rich than typical galaxies at the same stellar mass. At high mass, the cEs depart from the mass-metallicity relation of massive early-type galaxies, which forms a continuous sequence with dwarf galaxies. At lower mass, the metallicity distribution of ultracompact dwarfs (UCDs) changes at a few times 10^7 M⊙, which roughly coincides with the mass where luminosity function arguments previously suggested the GC population ends. The highest metallicities in CSSs are paralleled only by those of dwarf galaxy nuclei and the central parts of massive early types. These findings can be interpreted as CSSs previously being more massive and undergoing tidal interactions to obtain their current mass and compact size. Such an interpretation is supported by CSSs with direct evidence for tidal stripping, and by an examination of the CSS internal escape velocities.

Hydroxylation and translational adaptation to stress: some answers lie beyond the STOP codon

Hydroxylation and translational adaptation to stress: some answers lie beyond the STOP codon Katz, Maximiliano Javier; Gándara, Lautaro; de Lella Ezcurra, Ana Laura; Wappner, Pablo Regulation of protein synthesis contributes to maintenance of homeostasis and adaptation to environmental changes. mRNA translation is controlled at various levels including initiation, elongation and termination, through post-transcriptional/translational modifications of components of the protein synthesis machinery. Recently, protein and RNA hydroxylation have emerged as important enzymatic modifications of tRNAs, elongation and termination factors, as well as ribosomal proteins. These modifications enable a correct STOP codon recognition, ensuring translational fidelity. Recent studies are starting to show that STOP codon read-through is related to the ability of the cell to cope with different types of stress, such as oxidative and chemical insults, while correlations between defects in hydroxylation of protein synthesis components and STOP codon read-through are beginning to emerge. In this review we will discuss our current knowledge of protein synthesis regulation through hydroxylation of components of the translation machinery, with special focus on STOP codon recognition. We speculate on the possibility that programmed STOP codon read-through, modulated by hydroxylation of components of the protein synthesis machinery, is part of a concerted cellular response to stress.

RNA Structure Duplications and Flavivirus Host Adaptation

RNA Structure Duplications and Flavivirus Host Adaptation Villordo, Sergio; Carballeda, Juan Manuel; Filomatori, Claudia Veronica; Gamarnik, Andrea Vanesa Flaviviruses include a highly diverse group of arboviruses with a global distribution and a high human disease burden. Most flaviviruses cycle between insects and vertebrate hosts; thus, they are obligated to use different cellular machinery for their replication and mount different mechanisms to evade specific antiviral responses. In addition to coding for viral proteins, the viral genome contains signals in RNA structures that govern the amplification of viral components and participate in triggering or evading antiviral responses. In this review, we focused on new information about host-specific functions of RNA structures present in the 3' untranslated region (3' UTR) of flavivirus genomes. Models and conservation patterns of RNA elements of distinct flavivirus ecological groups are revised. An intriguing feature of the 3' UTR of insect-borne flavivirus genomes is the conservation of complex RNA structure duplications. Here, we discuss new hypotheses of how these RNA elements specialize for replication in vertebrate and invertebrate hosts, and present new ideas associating the significance of RNA structure duplication, small subgenomic flavivirus RNA formation, and host adaptation.

Arbuscular mycorrhizal fungal diversity in rhizosphere spores versus roots of an endangered endemic tree from Argentina: Is fungal diversity similar among forest disturbance types?

Arbuscular mycorrhizal fungal diversity in rhizosphere spores versus roots of an endangered endemic tree from Argentina: Is fungal diversity similar among forest disturbance types? Soteras, María Florencia; Moreira, Bruno Coutinho; Grilli, Gabriel; Pastor, Nicolás; Mendes, Flávia Carneiro; Carvalho, Daniela Ruela de; Renison, Daniel; Kasuya, Maria Catarina Megumi; Souza, Francisco Adriano de; Becerra, Alejandra Gabriela The aim of this study was to compare the arbuscular mycorrhizalfungal (AMF) community of the rhizosphere and inside the roots of theperennial Polylepis australis tree. Three forest types differing in theirstructural complexity due to anthropogenic disturbances were chosen atthree different sites at the high mountains of central Argentina.Rhizosphere spores and P. australis roots of four randomly selected treeswere isolated from 36 soil samples, DNA was extracted and the 18S rDNAfragments were amplified by nested-PCR. The products were analyzed byDGGE and the bands were excised for sequencing. In total, 36 OTUs weredefined from 56 DGGE bands successfully sequenced. Forest disturbancetypes showed similar communities of AMF, as rhizosphere spores and withinthe roots of P. australis. However, DGGE clustering showed mainlydifferences between rhizosphere spores and root-colonizing AMF. Membersof Glomeraceae, Pacisporaceae, Acaulosporaceae and Gigasporaceae wereshown in rhizosphere spore samples. Root samples showed only members ofAcaulosporaceae and Gigasporaceae, which might be complementary in termsof soil resources exploration. The prevalence of the root system withtheir community of symbionts might explain the resilience of AMF soilcommunities to forests structural changes. This study presents evidenceof a possible preference in the AMF- P. australis interaction.

Contrasting effects of fire frequency on plant traits of three dominant perennial herbs from Chaco Serrano

Contrasting effects of fire frequency on plant traits of three dominant perennial herbs from Chaco Serrano Carbone, Lucas Manuel; Aguilar, Ramiro Fire frequencies are currently increasing inmany regions across the world as a result of anthropic activities, affecting ecological processes and plant population dynamics. Fire can generate important changes in soil properties, altering nutrient dynamics and thereby plant growth. Here we analyse fire frequency effects on soil quality and plant traits of three native perennial herbaceous plants (Cologania broussonetii, Desmodium uncinatum and Rhynchosia edulis; Fabaceae) with the capacity for biologicalN2 fixation that resprouts and is abundant after fire in Chaco Serrano forests. Based on 22-year fire history, we assessed plant traits in sites with low and high fire frequencies along with unburned scenarios. We found significantly lower water content, nitrates and electrical conductivity in frequently burned soils. As a result, the three species showed consistently lower leaf area and specific leaf area in both fire frequencies, implying lower growth rates in comparison to unburned sites. However, total leaf biomass was not affected by fire, leaf phosphorus concentration was higher in R. edulis in high fire frequency and leaf N concentration was twice as large in plants growing in sites of high fire frequency in C. broussonetii and R. edulis. Such an increase in N and phosphorus concentrations is likely a result of both their conservative use of resources and their biologicalN2 fixation capacity. To our knowledge, this is the first record of such contrasting fire effects observed consistently in three co-occurring species: while plant growth decreased with fire frequency, leaf nutritional traits remain unchanged or increased in frequently burned sites. Quality-depleted and drier soils that result fromincreased fire frequenciesmay not only affect trait variation at the intraspecific level but can also drive to a homogenization of the plant community, selecting species with particular combinations of morphological and functional traits.

Dynamic transition in Landau-Zener-Stückelberg interferometry of dissipative systems: the case of the flux qubit

Dynamic transition in Landau-Zener-Stückelberg interferometry of dissipative systems: the case of the flux qubit Ferrón, Alejandro; Domínguez, Daniel; Sánchez, María José We study Landau-Zener-Stückelberg (LZS) interferometry in multilevel systems coupled to an Ohmic quantum bath. We consider the case of superconducting flux qubits driven by a dc+ac magnetic fields, but our results can apply to other similar systems. We find a dynamic transition manifested by a symmetry change in the structure of the LZS interference pattern, plotted as a function of ac amplitude and dc detuning. The dynamic transition is from an LZS pattern with nearly symmetric multiphoton resonances to antisymmetric multiphoton resonances at long times (above the relaxation time). We also show that the presence of a resonant mode in the quantum bath can impede the dynamic transition when the resonant frequency is of the order of the qubit gap. Our results are obtained by a numerical calculation of the finite time and the asymptotic stationary population of the qubit states, using the Floquet-Markov approach to solve a realistic model of the flux qubit considering up to ten energy levels.

Effect of mineral matter removal on pyrolysis of wood sawdust from an invasive species

Effect of mineral matter removal on pyrolysis of wood sawdust from an invasive species Gurevich Messina, Luciano Ignacio; Bonelli, Pablo Ricardo; Cukierman, Ana Lea Kinetics of the pyrolysis of wood sawdust from the invasive species Parkinsonia aculeata, untreated and demineralized by a mild acid treatment, is comparatively investigated in order to examine the effect of the removal of minerals naturally present in the biomass. Non-isothermal thermogravimetric analysis from room temperature up to 500°C is applied for this purpose. Demineralization shifts the process onset and the maximum degradation rate to higher temperatures, and leads to enhance the activation energy from 56 to 60 kJ mol–1, pointing to a catalytic role of alkaline and alkaline earth metals in the biomass. Likewise, the three kinds of pyrolysis products (gas, bio-char, and bio-oil) are obtained from experiments performed in a bench-scale installation at 500°C. Yields and physicochemical characteristics of the pyrolysis products are determined. The pronounced reduction in the content of metals in the sawdust leads to increase bio-oil yield in around 10%, the specific surface area of the bio-char, from ≈ 2 to ≈ 74 m2 g–1, and the higher heating value of all the pyrolysis products.

Sign Conditions for Injectivity of Generalized Polynomial Maps with Applications to Chemical Reaction Networks and Real Algebraic Geometry

Sign Conditions for Injectivity of Generalized Polynomial Maps with Applications to Chemical Reaction Networks and Real Algebraic Geometry Müller, Stefan; Feliu, Elisenda; Regensburger, Georg; Conradi, Carsten; Shiu, Anne; Dickenstein, Alicia Marcela We give necessary and sufficient conditions in terms of sign vectors for the injectivity of families of polynomial maps with arbitrary real exponents defined on the positive orthant. Our work relates and extends existing injectivity conditions expressed in terms of Jacobian matrices and determinants. In the context of chemical reaction networks with power-law kinetics, our results can be used to preclude as well as to guarantee multiple positive steady states. In the context of real algebraic geometry, our work recognizes a prior result of Craciun, Garcia-Puente, and Sottile, together with work of two of the authors, as the first partial multivariate generalization of the classical Descartes’ rule, which bounds the number of positive real roots of a univariate real polynomial in terms of the number of sign variations of its coefficients.

Understanding trends in biological invasions by introduced mammals in southern South America: a review of research and management

Understanding trends in biological invasions by introduced mammals in southern South America: a review of research and management Ballari, Sebastián A.; Anderson, Christopher Brian; Valenzuela, Alejandro Eduardo Jorge Invasive introduced mammals (IIMs) have ecological and social dimensions that require holistic research to integrate academic disciplines with basic and applied sciences. We assessed current knowledge of IIMs to determine trends in their study and management in southern South America. A keyword search was used to select indexed papers in the Web of Science. These were reviewed to assess each study's objective, methodology, country, publication year, and taxa. Unpublished ‘grey’ literature was added to evaluate further each species’ native range, year of introduction, the reason for its introduction, its distribution, dispersal pathways, impacts, and management. Most of the 190 peer‐reviewed publications were focused on autecology and impacts of IIMs; less than 4% addressed management or social topics. Twenty‐three IIMs have been documented in the study area. The southern Magellanic subpolar forest was the most invaded ecoregion (17 spp.), and the most studied orders, from 440 records in 190 papers, were Artiodactyla (35%) and Rodentia (28%). Together, livestock and commensals brought during early European colonisation constituted 44% of this assemblage, but hunting was the major reason behind the introduction of IIMs (30%). To enhance policies and institutional frameworks pertaining to biological invasions, we highlight the importance of: 1) recognising the presence and spread of IIMs in ‘pristine’ or protected areas; 2) improving controls to prevent new introductions and escapes; 3) including social and cultural aspects of biological invasions in research and management plans; 4) reinforcing hunting regulations; 5) establishing long‐term programmes to monitor distribution and dispersion; 6) creating mechanisms for scientists and managers to co‐produce research and policy programmes oriented towards applied issues; 7) developing pilot management projects in critical areas; 8) achieving societal involvement in management programmes to ensure public acceptance; and 9) developing prioritisation tools, as resources needed to manage IIMs are often limited.

Determinantes de la equidad en el financiamiento de los medicamentos en Argentina: un estudio empírico

Determinantes de la equidad en el financiamiento de los medicamentos en Argentina: un estudio empírico; Determinants of equity in financing medicines in Argentina: an empirical study; Determinantes da equidade no financiamento de medicamentos na Argentina: um estudo empírico Dondo Bühler, Mariana Beatriz; Monsalvo, Mauricio; Garibaldi, Lucas Alejandro Los medicamentos constituyen un alto porcentaje del gasto en salud de los hogares, por eso, tener un sistema progresivo de financiamiento de medicamentos es fundamental para lograr un sistema de salud equitativo. Se ha propuesto que los determinantes de la equidad en el financiamiento son socioeconómicos, demográficos y asociados a la intervención pública, pero se ha avanzado poco en su evaluación empírica y en la cuantificación de su importancia relativa. En este trabajo estimamos regresiones por cuantiles a nivel provincial en Argentina y encontramos que la población mayor a 65 años, el desempleo, la existencia de laboratorio público de producción de medicamentos,las transferencias de tratamientos y la orientación del sistema desalud a la atención primaria son importantes predictores de la progresividad en el esquema de pagos. Ingresos bajos, instituciones débiles, infraestructura y provisión de servicios insuficientes redundan en respuestas sociales más regresivas a las necesidades sanitarias, empeorando las condiciones de vida y limitando las oportunidades de desarrollo.; Medicines are an important part of household health spending. A progressive system for financing drugs is thus essential for an equitable health system. Some authors have proposed that the determinants of equity in drug financing are socioeconomic, demographic, and associated with public interventions, but little progress has been made in the empirical evaluation and quantification of their relative importance. The current study estimated quantile regressions at the provincial level in Argentina and found that old age (> 65 years), unemployment, the existence of a public pharmaceutical laboratory, treatment transfers, and a health system orientated to primary care were important predictors of progressive payment schemes. Low income, weak institutions, and insufficient infrastructure and services were associated with the most regressive social responses to health needs, thereby aggravating living conditions and limiting development opportunities.; Medicamentos são uma parte importante dos gastos em saúde do agregado familiar, portanto, ter um sistema progressivo de financiamento de medicamentos é fundamental para alcançar um sistema de saúde equitativo. Foi proposto que os determinantes da equidade no financiamento são fatores socioeconômicos, demográficos e ligados à intervenção pública, mas se avançou pouco em sua avaliação empírica e na quantificação de sua importância relativa. Neste trabalho, estimamos regressões por quantis no nível provincial na Argentina e encontramos que a população maior de 65 anos, o desemprego, a existência de laboratório de produção pública de medicamentos, transferências de tratamentos e orientação do sistema de saúde para atenção primária são importantes preditores da progressividade dos sistemas de pagamento. Baixa renda, instituições fracas, infraestrutura e oferta insuficiente de serviços resultam em mais regressivas respostas sociais às necessidades de saúde, agravando as condições de vida e limitando as oportunidades de desenvolvimento.

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