A response surface methodology approach to investigate the effect of sulfur dioxide, pH, and ethanol on DbCD and DbVPR gene expression and on the volatile phenol production in Dekkera/Brettanomyces bruxellensis CBS2499

Dekkera/Brettanomyces bruxellensis, the main spoilage yeast in barrel-aged wine, metabolize hydroxycinnamic acids into off-flavors, namely ethylphenols. Recently, both the enzymes involved in this transformation, the cinnamate decarboxylase (DbCD) and the vinylphenol reductase (DbVPR), have been identified. To counteract microbial proliferation in wine, sulfur dioxide (SO2) is used commonly to stabilize the final product, but limiting its use is advised to preserve human health and boost sustainability in winemaking. In the present study, the influence of SO2was investigated in relation with pH and ethanol factors on the expression of DbCD and DbVPR genes and volatile phenol production in D. bruxellensis CBS2499 strain under different model wines throughout a response surface methodology (RSM). In order to ensure an exact quantification of DbCD and DbVPR expression, an appropriate housekeeping gene was sought among DbPDC, DbALD, DbEF, DbACT, and DbTUB genes by GeNorm and Normfinder algorithms. The latter gene showed the highest expression stability and it was chosen as the reference housekeeping gene in qPCR assays. Even though SO2could not be commented as main factor because of its statistical irrelevance on the response of DbCD gene, linear interactions with pH and ethanol concurred to define a significant effect (p < 0.05) on its expression. The DbCD gene was generally downregulated respect to a permissive growth condition (0 mg/L mol. SO2, pH 4.5 and 5% v/v ethanol); the combination of the factor levels that maximizes its expression (0.83-fold change) was calculated at 0.25 mg/L mol. SO2, pH 4.5 and 12.5% (v/v) ethanol. On the contrary, DbVPR expression was not influenced by main factors or by their interactions; however, its expression is maximized (1.80-fold change) at the same conditions calculated for DbCD gene. While no linear interaction between factors influenced the off-flavor synthesis, ethanol and pH produced a significant effect as individual factors. The obtained results can be useful to improve the SO2management at the grape harvesting and during winemaking in order to minimize the D./B. bruxellensis spoilage

Tree regeneration and microclimate in a liana and bamboo-dominated semideciduous Atlantic Forest

We assessed the effect of native bamboo and lianas on microclimate, tree regeneration and forest structure in a semi-deciduous Atlantic Forest subjected to selective timber extraction during the last century. We hypothetized that bamboo and liana cutting would increase incoming solar radiation in the understory promoting establishment and survival of pioneer and light-requiring canopy tree species. A manipulative experiment consisting of bamboo and liana cutting was performed in a native forest stand in northeastern Argentina. In three permanent 1-ha plots bamboo and lianas were cut and allowed to decompose in situ, while other three plots were used as a control treatment. We measured solar radiation reaching the understory, soil water availability and air temperature in both bamboo and liana cutting and control plots. Tree sapling abundance and richness, stand basal area, bamboo density, and cover of lianas, herbs, shrubs, fallen trees and branches were also determined. We performed multivariate analyses to relate tree sapling abundance and richness with biotic and abiotic factors. Bamboo and liana cutting increased by 100% the solar radiation reaching the understory. The fraction of solar radiation transmitted at 0.7 m height above ground in control and treated plots was 0.1 and 0.2, respectively. Minimum soil matric potentials after a severe dry spell were less than ‚à í2 MPa. Soil water availability was higher under closed-canopy in the treated plots because liana transpiration was prevented by cutting. Although bamboo and liana cutting increased incoming solar radiation, tree seedling and sapling abundance of pioneer and light-demanding species was not improved by the treatment. Instead, an increased abundance of herbaceous plants was observed in gaps and open canopy areas (i.e., sites with amounts of herb cover greater than 75% represented the 11 and 2% of the total number of sites in treated and control plots, respectively). Sapling survival and growth rates, on the other hand, appeared to be promoted by bamboo and liana cutting. Bamboo inhibited tree sapling abundance and richness in gaps, whereas tree basal area had a positive effect. In the semideciduous Atlantic Forest, native bamboos modify gap phase regeneration, and may affect canopy cover and forest composition in the long term. Post-logging management techniques are needed for sustainable timber production in these forest stands

Thinning of loblolly pine plantations in subtropical Argentina: Impact on microclimate and understory vegetation

During the last three decades, the area dedicated to tree plantations in northeast of Argentina has increased five-fold at the expense of the native semideciduous Atlantic Forest. Silvicultural practices such as thinning affect the understory and forest floor incrementing vegetation cover and diversity that may impact ecological functions such as carbon and nutrient cycling and provide food and shelter for wildlife. The aim of this study was to assess the effects of two thinning intensities (50% and 30% of individual removal), and litter removal in the 50% thinning treatment on the understory vegetation of loblolly pine (Pinus taeda L.). The high thinning intensity and the control without thinning were intended to recreate existing management practices in the region. The study was carried out in three Pinus taeda plantations (replicates). Environmental conditions and cover of native understory vegetation were measured during two years after thinning. Canopy openness, solar radiation, air temperature and soil bulk density were higher in thinning treatments than in control plots while soil water content was lower. Vegetation cover and richness increased with intensity of the thinning treatments. Tree saplings differed in the responses according to light requirements and height. Light-demanding species and individuals taller than 0.5 m were responsive to thinning increasing coverage, abundance and height, while smaller saplings were more abundant in control plots. No effects of litter removal were observed in understory species richness and plant cover. This study provides evidence that thinning on pine plantations in Northeastern Argentina can contribute in maintaining biodiversity and related ecosystem functions of subtropical forests. Management practices involving lower plantation densities and fewer interventions should be developed to achieve more positive effects.Fil: Trentini, Carolina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Campanello, Paula Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Villagra, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Ritter, Luis Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Ares, A.. University of Arkansas; Estados UnidosFil: Goldstein, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentin

Timely Recognition and Early Multi-Step Antinflammatory Therapy May Prevent ICU Admission of Patients With MIS-C: Proposal for a Severity Score

In this observational study, we report the clinical, therapeutics and outcome features of 23 patients with multisystem inflammatory syndrome (MIS-C) who have been treated in Gaslini Children Hospital (Genoa, Italy) with a multistep antinflammatory treatment protocol, based on disease severity at admission. Patients were initially assigned to four severity classes on admission and treated accordingly. The therapeutic options ranged from IV immunoglobulin alone to a combination of IVIG plus pulses of methylprednisolone plus anakinra for patients with marked cardiac function impairment or signs of macrophage activation syndrome, with rapid treatment escalation in case of inadequate therapeutic response. With the application of this therapeutic strategy, no patient required admission to Intensive Care Unit (ICU) or invasive mechanical ventilation, and no inotropic drugs administration was required. Early aggressive treatment of MIS-C, with therapeutic interventions modulated based on the severity of clinical manifestations may help to prevent the progression of the inflammatory process and to avoid the need of admission to the ICU. A timely intervention with anti-IL-1 blockers can play a pivotal role in very severe patients that are at risk to have an incomplete response to immunoglobulins and steroids

Crown structural properties, wood density, and liana load: Influence on growth and mortality in subtropical forests

Wood density (WD) and other wood mechanical and structural properties may have a strong functional relationship with demographic patterns and allometry of trees. We analyzed the influence of WD, structural properties, architectural traits, and community-level attributes on growth rates (GRs) and mortality modes of canopy tree species in a subtropical forest of Argentina. Stem WD and the WD, strength, stiffness, toughness, and hardness of branches were measured in 10 canopy species. Architectural traits and liana load were also determined. Strength and hardness of branches were linearly correlated to branch WD, and GRs were linearly correlated to stem WD across species. At the individual level, trees with greater hardness and toughness in branches died mostly uprooted, and trees with greater branch stiffness and susceptibility to colonization by lianas were mostly broken. At the community level, the suppressed trees died mostly broken. The dominant trees with high local tree density died mostly broken, whereas more isolated trees died mostly uprooted. Mortality modes were determined not only by mechanical properties, but also by community properties such as liana load, crown canopy position, and number of neighboring trees. Other biophysical traits besides WD are important explanatory variables when dry wood is used to describe functional characteristics of trees.La densité du bois (DB) et d’autres propriétés mécaniques et structurales pourraient avoir une étroite relation fonctionnelle avec les patrons démographiques et l’allométrie des arbres. Nous avons analysé l’influence de la DB, des pro priétés structurales, des traits architecturaux et des attributs à l’échelle de la communauté sur le taux de croissance (TC) et la cause de mortalité des espèces arborescentes dominantes dans une forêt subtropicale en Argentine. La DB du tronc ainsi que la DB, la résistance, la rigidité, la ténacité et la dureté des branches ont été mesurées chez 10 espèces dominantes. De plus, les traits architecturaux et la charge de lianes ont été déterminés. La résistance et la dureté des branches étaient liné airement corrélées à la DB des branches et le TC était linéairement corrélé à la DB du tronc chez l’ensemble des espèces. À l’échelle individuelle, les arbres dont les branches avaient la plus grande dureté et la plus grande ténacité sont le plus sou vent morts renversés et ceux dont les branches avaient la plus grande rigidité et qui étaient les plus sujets à être colonisés par les lianes sont morts pour la plupart après avoir été cassés. À l’échelle de la communauté, les arbres supprimés sont morts pour la plupart après avoir été cassés. Les arbres dominants dont la densité était localement élevée sont surtout morts après avoir été cassés tandis que les arbres plus isolés son surtout morts après avoir été déracinés. La façon dont la mortalité est survenue était déterminée par les propriétés mécaniques mais aussi par les propriétés de la communauté, telles que la charge de lianes, la position de la cime dans le couvert et le nombre d’arbres avoisinants. D’autres traits bio physiques à part la DB sont d’importantes variables explicatives lorsque du bois sec est utilisé pour décrire les caractéris tiques fonctionnelles des arbres.Fil: Rodríguez, Sabrina A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Cristiano, Piedad María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Lezcano, Oscar A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Suirezs, Teresa Maria. Universidad Nacional de Misiones; ArgentinaFil: Díaz Villa, M. Virginia E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bucci, Sandra Janet. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Goldstein, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. University of Miami; Estados UnidosFil: Campanello, Paula Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ingeniería - Sede Esquel. Centro de Estudios Ambientales Integrados; Argentin

Functional Role of Solvent Entropy and Conformational Entropy of Metal Binding in a Dynamically Driven Allosteric System

Allostery is a regulatory phenomenon whereby ligand binding to one site influences the binding of the same or a different ligand to another site on a macromolecule. The physical origins of allosteric regulation remain under intense investigation. In general terms, ligand-induced structural changes, perturbations of residue-specific dynamics, and surrounding solvent molecules all potentially contribute to the global energetics of allostery. While the role of solvent is generally well understood in regulatory events associated with major protein structural rearrangements, the degree to which protein dynamics impact solvent degrees of freedom is unclear, particularly in cases of dynamically driven allostery. With the aid of new crystal structures, extensive calorimetric and residue-specific dynamics studies over a range of time scales and temperatures, we dissect for the first time the relative degree to which changes in solvent entropy and residue-specific dynamics impact dynamically driven, allosteric inhibition of DNA binding by Zn in the zinc efflux repressor, CzrA (chromosomal zinc-regulated repressor). We show that non-native residue-specific dynamics in allosterically impaired CzrA mutants are accompanied by significant perturbations in solvent entropy that cannot be predicted from crystal structures. We conclude that functional dynamics are not necessarily restricted to protein residues but involve surface water molecules that may be responding to ligand (Zn)-mediated perturbations in protein internal motions that define the conformational ensemble, rather than major structural rearrangements

Geographical, taxonomical and ecological aspects of lianas in subtropical forests of Argentina

Lianas are more diverse and typically more abundant in tropical than temperate forests, with subtropical forests being intermediate. In this chapter, we analyse geographical, taxonomical and ecological patterns of lianas in subtropical forests of northern Argentina, including Mountain Forests (MF), Atlantic Forests (AF); and Dry and Humid Chaco Forests (DCh and HCh, respectively). A total of 184 woody species of climbing plants were recognized in all four subtropical forests, with 35 species exclusive to MF, 38 exclusive to AF, while DCh and HCh had 2 and 8 exclusive species, respectively. In MF most liana species belonged to Sapindaceae and Bignoniaceae (16% each), followed by Malpighiaceae (11%) and Apocynaceae (10%). In AF most liana species belonged to Bignoniaceae (21%) followed by Apocynaceae (12%), Fabaceae (11%), Malpighiaceae (11%) and Sapindaceae (10%). Considering all liana species together, the most common climbing mechanisms include tendrils and twiners. The highest liana density was observed in the semideciduous Atlantic Forest, followed by the deciduous Humid Chaco Forest and the semideciduous Montane Forest. The semideciduous Atlantic Forest has also relatively high liana species richness as compared to other subtropical forests, followed by semideciduous MF. Besides geographical location and forest disturbances, little is known about how lianas respond to other environmental factors that drive patterns of liana density and diversity in these subtropical forests.Fil: Malizia, Agustina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Campanello, Paula Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Villagra, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Ceballos, Sergio Javier. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentin