Unique thermal behavior of sphingomyelin species with nonhydroxy and 2-hydroxy very-long-chain (C28-C32) PUFAs

In rat germ cells and spermatozoa, sphingomyelin (SM) contains molecular species with nonhydroxy (n) and 2-hydroxy (h) very-long-chain polyunsaturated fatty acids (V), the most abundant being SMs with (n- and h-) 28:4n-6, 30:5n-6, and 32:5n-6 as acyl chains. The aim of this study was to gain information about their thermotropic behavior and interactions with other lipids. After isolation from rat testis, multilamellar and giant unilamellar vesicles from these SMs were examined using fluorescent probes. Only n-32:5 SM and h-32:5 SM displayed a gel-liquid transition temperature (Tt ≈ 21?22°C), the rest remaining in the liquid state in the 5°C?45°C range. The degree of order was larger in bilayers of any of the h-V SMs than in those of their chain-matched n-V SMs. Both, but n-V SM relatively more than h-V SM, decreased the Tt of dimyristoylphosphatidylcholine as their proportion increased in binary phosphatidylcholine:SM liposomes. In contrast to the established ability of 16:0 SM to form lateral cholesterol/SM-rich ordered domains in ternary dioleoylphosphatidylcholine:cholesterol:SM bilayers, neither n-V SM nor h-V SM showed a tendency to do so. Thus, these SMs are in the fluid state and are not involved in this type of domains in spermatozoa at physiological temperatures. However, this state could be altered at the very low temperatures at which these gametes are usually preserved.Fil: Peñalva, Daniel Alejandro. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Furland, Natalia Edith. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Lopez, Gustavo H.. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Antollini, Silvia Susana. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentin

Mechanistic Insights into the Light-Driven Catalysis of an Immobilized Lipase on Plasmonic Nanomaterials

The use of light as an external stimulus to control the enzyme activity is an emerging strategy that enables accurate, remote, and noninvasive biotransformations. In this context, immobilization of enzymes on plasmonic nanoparticles offers an opportunity to create light-responsive biocatalytic materials. Nevertheless, a fundamental and mechanistic understanding of the effects of localized surface plasmon resonance (LSPR) excitation on enzyme regulation remains elusive. We herein investigate the plasmonic effects on biocatalysis using Au nanospheres (AuNSp) and nanostars (AuNSt) as model plasmonic nanoparticles, lipase from Candida antarctica fraction B (CALB) as a proof-of-concept enzyme, and 808 nm as near-infrared light excitation. Our data show that LSPR excitation enables an enhancement of 58% in the enzyme activity for CALB adsorbed on AuNSt, compared with the dark conditions. This work shows how photothermal heating over the LSPR excitation enhances the CALB activity through favoring product release in the last step of the enzyme mechanism. We propose that the results reported herein shed important mechanistic and kinetic insights into the field of plasmonic biocatalysis and may inspire the rational development of plasmonic nanomaterial-enzyme hybrids with tailored activities under external light irradiation.Peer reviewe

Above- and belowground carbon stocks are decoupled in secondary tropical forests and are positively related to forest age and soil nutrients respectively

Reducing atmospheric CO2 is an international priority. One way to assist stabilising and reducing CO2 is to promote secondary tropical forest regrowth on abandoned agricultural land. However, relationships between above- and belowground carbon stocks with secondary forest age and specific soil nutrients remain unclear. Current global estimates for CO2 uptake and sequestration in secondary tropical forests focus on aboveground biomass and are parameterised using relatively coarse metrics of soil fertility. Here, we estimate total carbon stocks across a chronosequence of regenerating secondary forest stands (40–120 years old) in Panama, and assess the relationships between both above- and belowground carbon stocks with stand age and specific soil nutrients. We estimated carbon stocks in aboveground biomass, necromass, root biomass, and soil. We found that the two largest carbon pools - aboveground biomass and soil – have distinct relationships with stand age and soil fertility. Aboveground biomass contained ~61-97 Mg C ha-1 (24-39 % total carbon stocks) and significantly increased with stand age, but showed no relationship with soil nutrients. Soil carbon stocks contained ~128-206 Mg C ha-1 (52-70 % total stocks) and were unrelated to stand age, but were positively related to soil nitrogen. Root biomass carbon stocks tracked patterns exhibited by aboveground biomass. Necromass carbon stocks did not increase with stand age, but stocks were held in larger pieces of deadwood in older stands. Comparing our estimates to published data from younger and older secondary forests in the surrounding landscape, we show that soil carbon recovers within 40 years of forest regeneration, but aboveground biomass carbon stocks continue to increase past 100 years. Above- and belowground carbon stocks appear to be decoupled in secondary tropical forests. Paired measures of above- and belowground carbon stocks are necessary to reduce uncertainty in large-scale models of atmospheric CO2 uptake and storage by secondary forests

Incomplete recovery of tree community composition and rare species after 120 years of tropical forest succession in Panama

Determining how fully tropical forests regenerating on abandoned land recover characteristics of old-growth forests is increasingly important for understanding their role in conserving rare species and maintaining ecosystem services. Despite this, our understanding of forest structure and community composition recovery throughout succession is incomplete, as many tropical chronosequences do not extend beyond the first 50 years of succession. Here, we examined trajectories of forest recovery across eight 1-hectare plots in middle and later stages of forest succession (40–120 years) and five 1-hectare old-growth plots, in the Barro Colorado Nature Monument (BCNM), Panama. We first verified that forest age had a greater effect than edaphic or topographic variation on forest structure, diversity and composition and then corroborated results from smaller plots censused 20 years previously. Tree species diversity (but not species richness) and forest structure had fully recovered to old-growth levels by 40 and 90 years, respectively. However, rare species were missing, and old-growth specialists were in low abundance, in the mid- and late secondary forest plots, leading to incomplete recovery of species composition even by 120 years into succession. We also found evidence that dominance early in succession by a long-lived pioneer led to altered forest structure and delayed recovery of species diversity and composition well past a century after land abandonment. Our results illustrate the critical importance of old-growth and old secondary forests for biodiversity conservation, given that recovery of community composition may take several centuries, particularly when a long-lived pioneer dominates in early succession

Nanoinformatics: developing new computing applications for nanomedicine

Nanoinformatics has recently emerged to address the need of computing applications at the nano level. In this regard, the authors have participated in various initiatives to identify its concepts, foundations and challenges. While nanomaterials open up the possibility for developing new devices in many industrial and scientific areas, they also offer breakthrough perspectives for the prevention, diagnosis and treatment of diseases. In this paper, we analyze the different aspects of nanoinformatics and suggest five research topics to help catalyze new research and development in the area, particularly focused on nanomedicine. We also encompass the use of informatics to further the biological and clinical applications of basic research in nanoscience and nanotechnology, and the related concept of an extended ?nanotype? to coalesce information related to nanoparticles. We suggest how nanoinformatics could accelerate developments in nanomedicine, similarly to what happened with the Human Genome and other -omics projects, on issues like exchanging modeling and simulation methods and tools, linking toxicity information to clinical and personal databases or developing new approaches for scientific ontologies, among many others

Biocultural approaches to sustainability : A systematic review of the scientific literature

Current sustainability challenges demand approaches that acknowledge a plurality of human-nature interactions and worldviews, for which biocultural approaches are considered appropriate and timely. This systematic review analyses the application of biocultural approaches to sustainability in scientific journal articles published between 1990 and 2018 through a mixed methods approach combining qualitative content analysis and quantitative multivariate methods. The study identifies seven distinct biocultural lenses, that is, different ways of understanding and applying biocultural approaches, which to different degrees consider the key aspects of sustainability science-inter- and transdisciplinarity, social justice and normativity. The review suggests that biocultural approaches in sustainability science need to move from describing how nature and culture are co-produced to co-producing knowledge for sustainability solutions, and in so doing, better account for questions of power, gender and transformations, which has been largely neglected thus far. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.Peer reviewe

Captura y almacenamiento de carbono como servicio ambiental en el bosque de q’euña “La Paz” Parque Arqueológico de Sacsayhuamán, Cusco

El presente estudio se realizó en el bosque de q’euña La Paz, ubicado en el Parque Arqueológico de Sacsayhuamán, distrito, provincia y región Cusco, en el año 2017, con la finalidad de evaluar la captura y almacenamiento de carbono como servicio ambiental, se utilizó el método cartográfico mediante el S.I.G. utilizando el Software Arcgis 10.4 y como instrumento el GPS, para la captura de carbono se aplicó el método estandarizado RAINFOR de estimación cuantitativa mediante las ecuaciones alométricas de Chave et. al 2005 y Sarcca 2017, empleadas para el cálculo de contenido de carbono en biomasa aérea y el método cuantitativo para determinar la valoración económica de captura y almacenamiento de carbono como servicio ambiental, llegando a las siguientes conclusiones, el área de bosque de Q’euña “La Paz” es de 31 838 m2 respecto a la captura y almacenamiento de carbono de la biomasa aérea de árboles de Q’euña, presentan un stock de carbono total de 14.16 tnC utilizando la ecuación alométrica de Chave 2005 y 20.61 tnCha, utilizando la ecuación alométrica de Sarcca 2017, dde acuerdo a la valoración económica de la captura y almacenamiento de carbono de la biomasa aérea como servicio ambiental para el bosque de Polylepis asciende a 537.64 y 782.31 euros utilizando las ecuaciones alométricas de Chave 2005 y Sarcca 2017 respectivamente

RASSF1A–LATS1 signalling stabilizes replication forks by restricting CDK2-mediated phosphorylation of BRCA2

Genomic instability is a key hallmark of cancer leading to tumour heterogeneity and therapeutic resistance. ​BRCA2 has a fundamental role in error-free DNA repair but also sustains genome integrity by promoting ​RAD51 nucleofilament formation at stalled replication forks. ​CDK2 phosphorylates ​BRCA2 (pS3291-​BRCA2) to limit stabilizing contacts with polymerized ​RAD51; however, how replication stress modulates ​CDK2 activity and whether loss of pS3291-​BRCA2 regulation results in genomic instability of tumours are not known. Here we demonstrate that the Hippo pathway kinase ​LATS1 interacts with ​CDK2 in response to genotoxic stress to constrain pS3291-​BRCA2 and support ​RAD51 nucleofilaments, thereby maintaining genomic fidelity during replication stalling. We also show that ​LATS1 forms part of an ​ATR-mediated response to replication stress that requires the tumour suppressor ​RASSF1A. Importantly, perturbation of the ​ATR–​RASSF1A–​LATS1 signalling axis leads to genomic defects associated with loss of ​BRCA2 function and contributes to genomic instability and ‘BRCA-ness’ in lung cancers

Production of electrospun fast-dissolving drug delivery systems with therapeutic eutectic systems encapsulated in gelatin

Fast-dissolving delivery systems (FDDS) have received increasing attention in the last years. Oral drug delivery is still the preferred route for the administration of pharmaceutical ingredients. Nevertheless, some patients, e.g. children or elderly people, have difficulties in swallowing solid tablets. In this work, gelatin membranes were produced by electrospinning, containing an encapsulated therapeutic deep-eutectic solvent (THEDES) composed by choline chloride/mandelic acid, in a 1:2 molar ratio. A gelatin solution (30% w/ v) with 2% (v/v) of THEDES was used to produce electrospun fibers and the experimental parameters were optimized. Due to the high surface area of polymer fibers, this type of construct has wide applicability. With no cytotoxicity effect, and showing a fast-dissolving release profile in PBS, the gelatin fibers with encapsulated THEDES seem to have promising applications in the development of new drug delivery systems.The research leading to these results has received funding from Fundação para a Ciência e a Tecnologia (FCT) through the projects ENIGMA - PTDC/EQU-EPR/ 121491/2010 and UID/CTM/50025/2013, LAQVREQUIMTE: UID/QUI/50006/2013, UCIBIO-REQUIMTE: UID/Multi/04378/2013 (co-financed by the ERDF under the PT2020 Partnership Agreement [POCI-01-0145-FEDER- 007728]) and by FEDER through the COMPETE 2020 Programme. Marta Martins is grateful for financial support from FCT through the grant BIM/PTDC/EQUEPR/121491/ 2010/ENIGMA. This research has also received funding from the European Union Seventh Framework Programme (FP7/ 2007-2013) under grant agreement number REGPOTCT2012-316331-POLARIS and from the project BNovel smart and biomimetic materials for innovative regenerative medicine approaches^ RL1 - ABMR - NORTE-01-0124- FEDER-000016) co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio