597 research outputs found
Soil microbial communities in restored and unrestored coastal dune ecosystems in California
Most restoration projects involving invasive plant eradication tend to focus on plant removal with little consideration given to how these invasives change soil microbial communities. However, soil microorganisms can determine invasibility of habitats and, in turn, be altered by invasives once established, potentially inhibiting native plant establishment. We studied soil microbial communities in coastal dunes with varying invasion intensity and different restoration approaches (herbicide, mechanical excavation) at Point Reyes National Seashore. Overall, we found evidence of a strong link between bacterial and fungal soil communities and the presence of invasives and restoration approach. Heavily invaded sites were characterized by a lower abundance of putatively identified nitrifiers, fermentative bacteria, fungal parasites, and fungal dung saprotrophs and a higher abundance of cellulolytic bacteria and a class of arbuscular mycorrhizal fungi (Archaeosporomycetes). Changes in soil microbiota did not fully dissipate following removal of invasives using herbicide, with exception of reductions in cellulolytic bacteria and Archaeosporomycetes abundance. Mechanical restoration effectively removed both invasives and soil legacy effects by inverting or “flipping” rhizome-contaminated surface soils with soils from below and may have inadvertently induced other adverse effects on soils that impeded reestablishment of native dune plants. Land managers should consider additional measures to counteract lingering legacy effects and/or focus restoration efforts in areas where legacy effects are less pronounced
Selected phytochemical bioactive compounds as quorum sensing inhibitors
Bacterial infections remain an important problem for human health. The control of bacterial infections has been traditionally treated by inhibiting microbial growth using different types of antibiotics. However, the ability of different bacteria to resist the inhibitory action of antibiotics has become a global problem. In fact, there is an important need for the development of new antimicrobials that act on novel bacterial targets. Many pathogenic bacteria control their population and regulate gene expression in response to their cell population density using diffusible signalling com¬pounds. This type of communication has been referred to as “quorum sensing” (QS). This phenomenon can be essential for the synchronization of the virulence production factors, which make it an attractive therapeutic target. Therefore, the search of non-toxic compounds, which inhibit QS and so, the virulence of pathogenic bacteria can bring new alternatives for the treatment of bacterial infections in humans. In this work, we made an attempt to screen the anti-QS activity of 11 bioactive compounds extracted from fruits and vegetables using the biosensor strain, Chromobacterium violaceum. The anti-QS activity was determined quantifying the violacein production of the biosensor strain at three concentrations (50, 100 and 200 µg/ml). At least five of the tested compounds (cinnamaldehyde, pomegranate extracts, ellagic acid resveratrol and rutin) showed anti-QS activity against the biosensor strain. The obtained results showed the potential of bioactive compounds extracted from fruits and vegetables to be used as a new category of anti-pathogenic compounds against bacterial infections.Fil: Truchado , P.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Tomás Barberán, F.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Allende, A.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Ponce, Alejandra Graciela. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin
Symmetry breaking in small rotating cloud of trapped ultracold Bose atoms
We study the signatures of rotational and phase symmetry breaking in small
rotating clouds of trapped ultracold Bose atoms by looking at rigorously
defined condensate wave function. Rotational symmetry breaking occurs in narrow
frequency windows, where the ground state of the system has degenerated with
respect to the total angular momentum, and it leads to a complex wave function
that exhibits vortices clearly seen as holes in the density, as well as
characteristic vorticity. Phase symmetry (or gauge symmetry) breaking, on the
other hand, is clearly manifested in the interference of two independent
rotating clouds.Comment: 4 pages, 2 figure
Edge excitations and Topological orders in rotating Bose gases
The edge excitations and related topological orders of correlated states of a
fast rotating Bose gas are studied. Using exact diagonalization of small
systems, we compute the energies and number of edge excitations, as well as the
boson occupancy near the edge for various states. The chiral Luttinger-liquid
theory of Wen is found to be a good description of the edges of the bosonic
Laughlin and other states identified as members of the principal Jain sequence
for bosons. However, we find that in a harmonic trap the edge of the state
identified as the Moore-Read (Pfaffian) state shows a number of anomalies. An
experimental way of detecting these correlated states is also discussed.Comment: Results extended to larger systems. Improved presentatio
Aspectos legales de la fecundación in vitro. Un análisis de la necesidad de su regulación por el ordenamiento jurídico paraguayo
La fecundación in vitro, como una de las técnicas de reproducción asistida más utilizadas por las parejas que no consiguen procrear por los medios naturales, plantea una serie de cuestionamientos desde el punto de vista del derecho, máxime cuando no existe ninguna regulación jurídica al respecto. Para tratar de brindar alguna respuesta a las hipótesis que giran en torno de estos procedimientos de reproducción se ha recurrido a criterios éticos y científicos mediante el abordaje de temas directamente afectados por estas prácticas, como los derechos de familia, la protección de las personas por nacer y la determinación del vínculo biológico (filiación). A partir de estos temas se plantea la necesidad de la creación de una ley ‘ad hoc’ sobre técnicas de reproducción asistida, teniendo en cuenta la urgencia de consensuar un marco legal que se compadezca de la realidad y sea coherente con los tiempos actuales, tutelando el bienestar de las personas y la dignidad humana
The effects of polyphenols and other bioactives on human health
Although deficiencies in polyphenol intake do not result in specific deficiency diseases, adequate intake of polyphenols could confer health benefits, especially with regard to chronic diseases. Tea, cocoa, fruits, and berries, as well as vegetables, are rich in polyphenols. Flavan-3-ols from cocoa have been found to be associated with a reduced risk of stroke, myocardial infarction, and diabetes, as well as improvements in lipids, endothelial-dependent blood flow and blood pressure, insulin resistance, and systemic inflammation. The flavonoid quercetin and the stilbene resveratrol have also been associated with cardiometabolic health. Although polyphenols have been associated with improved cerebral blood flow, evidence of an impact on cognition is more limited. The ability of dietary polyphenols to produce clinical effects may be due, at least in part, to a bi-directional relationship with the gut microbiota. Polyphenols can impact the composition of the gut microbiota (which are independently associated with health benefits), and gut bacteria metabolize polyphenols into bioactive compounds that produce clinical benefits. Another critical interaction is that of polyphenols with other phytochemicals, which could be relevant to interpreting the health parameter effects of polyphenols assayed as purified extracts, whole foods, or whole food extracts
Identification of Botanical Biomarkers in Argentinean Diplotaxis Honeys: Flavonoids and Glucosinolates
To select and establish floral biomarkers of the botanical origin ofDiplotaxis tenuifoliahoneys, the flavonoids and glucosinolates present in bee-deposited nectar collected from hive combs (unripe honey) and mature honey from the same hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MSn. Glycosidic conjugates of the flavonols quercetin, kaempferol, and isorhamnetin were detected and characterized in unripe honey.D. tenuifoliamature honeys contained the aglycones kaempferol, quercetin, and isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of propolis-derived flavonoid aglycones (1765−3171 μg/100 g) and hydroxycinnamic acid derivatives (29−1514 μg/100 g). Propolis flavonoids were already present in the freshly deposited nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The flavonoids quercetin, kaempferol, and isorhamnetin and the glucosinolates detected in the samples could be used as complementary biomarkers for the determination of the floral origin of ArgentineanDiplotaxishoneys
Vortex nucleation in mesoscopic Bose superfluid and breaking of the parity symmetry
We analyze vortex nucleation in mezoscopic 2D Bose superfluid in a rotating
trap. We explicitly include a weakly anisotropic stirring potential, breaking
thus explicitly the axial symmetry. As the rotation frequency passes the
critical value the system undergoes an extra symmetry
change/breaking. Well below the ground state is properly described
by the mean field theory with an even condensate wave function. Well above
the MF solution works also well, but the order parameter becomes
odd. This phenomenon involves therefore a discrete parity symmetry breaking. In
the critical region the MF solutions exhibit dynamical instability. The true
many body state is a strongly correlated entangled state involving two
macroscopically occupied modes (eigenstates of the single particle density
operator). We characterize this state in various aspects: i) the eligibility
for adiabatic evolution; ii) its analytical approximation given by the
maximally entangled combination of two single modes; and finally iii) its
appearance in particle detection measurements.Comment: 14 pages, 27 figure
Ordered structures in rotating ultracold Bose gases
The characterization of small samples of cold bosonic atoms in rotating
microtraps has recently attracted increasing interest due to the possibility to
deal with a few number of particles per site in optical lattices. We analyze
the evolution of ground state structures as the rotational frequency
increases. Various kinds of ordered structures are observed. For atoms,
the standard scenario, valid for large sytems, is absent, and only gradually
recovered as increases. The vortex contribution to the total angular
momentum as a function of ceases to be an increasing function of
, as observed in experiments of Chevy {\it et al.} (Phys. Rev. Lett.
85, 2223 (2000)). Instead, for small , it exhibits a sequence of peaks
showing wide minima at the values of , where no vortices appear.Comment: 35 pages, 17 figure
Diet-derived bioavailable metabolites to tackle diabetes
Funding Information: Funding: This study was funded by Fundação para a Ciência e Tecnologia (FCT)/Ministério da Ciência e do Ensino Superior, grant numbers PTDC/BIA-MOL/31104/2017 (RM) and UIDB/04567/2020 and UIDP/ 04567/2020 (CBIOS). iNOVA4Health Research Unit (LISBOA—01–0145—FEDER—007344), which is cofunded by FCT/Ministério da Ciência e do Ensino Superior, through national funds, and by FEDER under the PT2020 Partnership Agreement, is also acknowledged. Authors would like to acknowledge FCT for the financial support of AFR (PD/BD/135504/2018); SF (UI/BD/151421/2021), and RM (CEEC/04567/CBIOS/2020).Diabetes remains one of the leading causes of deaths and co-morbidities in the world, with tremendous human, social and economic costs. Therefore, despite therapeutics and technological advancements, improved strategies to tackle diabetes management are still needed. One of the suggested strategies is the consumption of (poly)phenols. Positive outcomes of dietary (poly)phenols have been pointed out towards different features in diabetes. This is the case of ellagitannins, which are present in numerous foodstuffs such as pomegranate, berries, and nuts. Ellagitannins have been reported to have a multitude of effects on metabolic diseases. However, these compounds have high molecular weight and do not reach circulation at effective concentrations, being metabolized in smaller compounds. After being metabolized into ellagic acid in the small intestine, the colonic microbiota hydrolyzes and metabolizes ellagic acid into dibenzopyran-6-one derivatives, known as urolithins. These low molecular weight compounds reach circulation in considerable concentrations ranging until micromolar levels, capable of reaching target tissues. Different urolithins are formed throughout the metabolization process, but urolithin A, isourolithin A, and urolithin B, and their phase-II metabolites are the most frequent ones. In recent years, urolithins have been the focus of attention in regard to their effects on a multiplicity of chronic diseases, including cancer and diabetes. In this review, we will discuss the latest advances about the protective effects of urolithins on diabetes.publishersversionpublishe
- …