Design and characterization of BSA-mycophenolic acid nanocomplexes: Antiviral activity exploration.

The interactions between bovine serum albumin (BSA) and mycophenolic acid (MPA) were investigated in silico through molecular docking and in vitro, using fluorescence spectroscopy. Dynamic light scattering and scanning electron microscopy were used to figure out the structure of MPA-Complex (MPA-C). The binding affinity between MPA and BSA was determined, yielding a Kd value of (12.0 ± 0.7) µM, and establishing a distance of 17 Å between the BSA and MPA molecules. The presence of MPA prompted protein aggregation, leading to the formation of MPA-C. The cytotoxicity of MPA-C and its ability to fight Junín virus (JUNV) were tested in A549 and Vero cell lines. It was found that treating infected cells with MPA-C decreased the JUNV yield and was more effective than free MPA in both cell line models for prolonged time treatments. Our results represent the first report of the antiviral activity of this type of BSA-MPA complex against JUNV, as assessed in cell culture model systems. MPA-C shows promise as a candidate for drug formulation against human pathogenic arenaviruses.

Impacto de la edad, las comorbilidades y las complicaciones en pacientes con COVID-19 con síndrome de dificultad respiratoria aguda en la ventilación mecánica invasiva. Estudio multicéntrico observacional / Impact of Age, Comorbidities and Complications in COVID-19 Patients with Acute Respiratory Distress Syndrome on Invasive Mechanical Ventilation. An Observational Multicenter Study

Objetivos: Millones de pacientes con COVID-19 fueron internados en terapia intensiva en el mundo, la mitad desarrollaron síndrome de dificultad respiratoria aguda (SDRA) y recibieron ventilación mecánica invasiva (VMI), con una mortalidad del 50%. Analiza-mos cómo edad, comorbilidades y complicaciones, en pacientes con COVID-19 y SDRA que recibieron VMI, se asociaron con el riesgo de morir durante su hospitalización.Métodos: Estudio de cohorte observacional, retrospectivo y multicéntrico realizado en 5 hospitales (tres privados y dos públicos universitarios) de Argentina y Chile, durante el segundo semestre de 2020.Se incluyeron pacientes >18 años con infección por SARS-CoV-2 confirmada RT-PCR, que desarrollaron SDRA y fueron asistidos con VMI durante >48 horas, durante el se-gundo semestre de 2020. Se analizaron los antecedentes, las comorbilidades más fre-cuentes (obesidad, diabetes e hipertensión), y las complicaciones shock, insuficiencia renal aguda (IRA) y neumonía asociada a la ventilación mecánica (NAV), por un lado, y las alteraciones de parámetros clínicos y de laboratorio registrados.Resultados: El 69% era varón. La incidencia de comorbilidades difirió para los diferentes grupos de edad. La mortalidad aumentó significativamente con la edad (p<0,00001). Las comorbilidades, hipertensión y diabetes, y las complicaciones de IRA y shock se asociaron significativamente con la mortalidad. En el análisis multivariado, sólo la edad mayor de 60 años, la IRA y el shock permanecieron asociados con la mortalidad. Conclusiones: El SDRA en COVID-19 es más común entre los mayores. Solo la edad >60 años, el shock y la IRA se asociaron a la mortalidad en el análisis multivariado.

Objectives: Millions of patients with COVID-19 were admitted to intensive care world-wide, half developed acute respiratory distress syndrome (ARDS) and received invasive mechanical ventilation (IMV), with a mortality of 50%. We analyzed how age, comor-bidities and complications in patients with COVID-19 and ARDS who received IMV were associated with the risk of dying during their hospitalization.Methods: Observational, retrospective and multicenter cohort study carried out in 5 hospitals (three private and two public university hospitals) in Argentina and Chile, during the second half of 2020.Patients >18 years of age with SARS-CoV-2 infection confirmed by RT-PCR, who devel-oped ARDS and were assisted with IMV for >48 hours, during the second half of 2020, were included. History, the most frequent comorbidities (obesity, diabetes and hyper-tension) and the complications of shock, acute renal failure (AKI) and pneumonia as-sociated with mechanical ventilation (VAP), on the one hand, and the alterations of re-corded clinical and laboratory parameters, were analyzed.Results: 69% were men. The incidence of comorbidities differed for different age groups. Mortality increased significantly with age (p<0.00001). Comorbidities, hyper-tension and diabetes, and complications of ARF and shock were significantly associat-ed with mortality. In the multivariate analysis, only age over 60 years, ARF and shock remained associated with mortality.Conclusions: ARDS in COVID-19 is more common among the elderly. Only age >60 years, shock and ARF were associated with mortality in the multivariate analysis

Plant Extracts and Phytochemicals from the Asteraceae Family with Antiviral Properties.

Asteraceae (Compositae), commonly known as the sunflower family, is one of the largest plant families in the world and includes several species with pharmacological properties. In the search for new antiviral candidates, an in vitro screening against dengue virus (DENV) was performed on a series of dichloromethane and methanolic extracts prepared from six Asteraceae species, including Acmella bellidioides, Campuloclinium macrocephalum, Grindelia pulchella, Grindelia chiloensis, Helenium radiatum, and Viguiera tuberosa, along with pure phytochemicals isolated from Asteraceae: mikanolide (1), eupatoriopicrin (2), eupahakonenin B (3), minimolide (4), estafietin (5), 2-oxo-8-deoxyligustrin (6), santhemoidin C (7), euparin (8), jaceidin (9), nepetin (10), jaceosidin (11), eryodictiol (12), eupatorin (13), and 5-demethylsinensetin (14). Results showed that the dichloromethane extracts of C. macrocephalum and H. radiatum and the methanolic extracts prepared from C. macrocephalum and G. pulchella were highly active and selective against DENV-2, affording EC50 values of 0.11, 0.15, 1.80, and 3.85 µg/mL, respectively, and SIs of 171.0, 18.8, >17.36, and 64.9, respectively. From the pool of phytochemicals tested, compounds 6, 7, and 8 stand out as the most active (EC50 = 3.7, 3.1, and 6.8 µM, respectively; SI = 5.9, 6.7, and >73.4, respectively). These results demonstrate that Asteraceae species and their chemical constituents represent valuable sources of new antiviral molecules.

Effects of the Natural Flavonoid Quercetin on Arenavirus Junín Infection.

There is no specific chemotherapy approved for the treatment of pathogenic arenaviruses that cause severe hemorrhagic fever (HF) in the population of endemic regions in America and Africa. The present study reports the effects of the natural flavonoid quercetin (QUER) on the infection of A549 and Vero cells with Junín virus (JUNV), agent of the Argentine HF. By infectivity assays, a very effective dose-dependent reduction of JUNV multiplication was shown by cell pretreatment at 2-6 h prior to the infection at non-cytotoxic concentrations, with 50% effective concentration values in the range of 6.1-7.5 µg/mL. QUER was also active by post-infection treatment but with minor efficacy. Mechanistic studies indicated that QUER mainly affected the early steps of virus adsorption and internalization in the multiplication cycle of JUNV. Treatment with QUER blocked the phosphorylation of Akt without changes in the total protein expression, detected by Western blot, and the consequent perturbation of the PI3K/Akt pathway was also associated with the fluorescence redistribution from membrane to cytoplasm of TfR1, the cell receptor recognized by JUNV. Then, it appears that the cellular antiviral state, induced by QUER treatment, leads to the prevention of JUNV entry into the cell.

Differential diagnosis for two 'holes in the head' of a child from 982 to 904 BP in northern South America.

OBJECTIVE: To present paleopathological evidence of a congenital anomaly with photographic support and a review that will help scholars to diagnose the condition. MATERIALS: Well-preserved skeletal remains of a child from central Colombia, dated 968-1046 CE. METHODS: Macroscopic examination and computerized axial tomography. RESULTS: Two holes were observed in the skull. CONCLUSIONS: The pathology is consistent with a neural tube defect or an inclusion cyst. SIGNIFICANCE: Neural tube defects and inclusion cysts, in paleopathology, are rarely reported in children. The preservation and origin of the individual make this case valuable. The photographic support and the review is useful for other scholars in the field. LIMITATIONS: It was not possible to determine a single cause. SUGGESTIONS FOR FUTURE RESEARCH: Review cases in identified osteological collections.

cis-Acting Element at the 5' Noncoding Region of Tacaribe Virus S RNA Modulates Genome Replication.

Tacaribe virus (TCRV) is the prototype of New World mammarenaviruses, a group that includes several members that cause hemorrhagic fevers in humans. The TCRV genome comprises two RNA segments, named S (small) and L (large). Both genomic segments contain noncoding regions (NCRs) at their 5' and 3' ends. While the 5'- and 3'-terminal 19-nucleotide sequences are known to be essential for promoter function, the role of their neighboring internal noncoding region (iNCR) sequences remains poorly understood. To analyze the relevance of the 5' and 3' iNCRs in TCRV S RNA synthesis, mutant S-like minigenomes and miniantigenomes were generated. Using a minireplicon assay, Northern blotting, and reverse transcription-quantitative PCR, we demonstrated that the genomic 5' iNCR is specifically engaged in minigenome replication yet is not directly involved in minigenome transcription, and we showed that the S genome 3' iNCR is barely engaged in this process. Analysis of partial deletions and point mutations, as well as total or partial substitution of the 5' iNCR sequence, led us to conclude that the integrity of the whole genomic 5' iNCR is essential and that a local predicted secondary structure or RNA-RNA interactions between the 5' and 3' iNCRs are not strictly required for viral S RNA synthesis. Furthermore, we employed a TCRV reverse genetic approach to ask whether manipulation of the S genomic 5' iNCR sequence may be suitable for viral attenuation. We found that mutagenesis of the 5' promoter-proximal subregion slightly impacted recombinant TCRV virulence in vivo. IMPORTANCE The Mammarenavirus genus of the Arenaviridae family includes several members that cause severe hemorrhagic fevers associated with high morbidity and mortality rates, for which no FDA-approved vaccines and limited therapeutic resources are available. We provide evidence demonstrating the specific involvement of the TCRV S 5' noncoding sequence adjacent to the viral promoter in replication. In addition, we examined the relevance of this region in the context of an in vivo infection. Our findings provide insight into the mechanism through which this 5' viral RNA noncoding region assists the L polymerase for efficient viral S RNA synthesis. Also, these findings expand our understanding of the effect of genetic manipulation of New World mammarenavirus sequences aimed at the rational design of attenuated recombinant virus vaccine platforms.

Target enrichment of long open reading frames and ultraconserved elements to link microevolution and macroevolution in non-model organisms.

Despite the increasing accessibility of high-throughput sequencing, obtaining high-quality genomic data on non-model organisms without proximate well-assembled and annotated genomes remains challenging. Here, we describe a workflow that takes advantage of distant genomic resources and ingroup transcriptomes to select and jointly enrich long open reading frames (ORFs) and ultraconserved elements (UCEs) from genomic samples for integrative studies of microevolutionary and macroevolutionary dynamics. This workflow is applied to samples of the African unionid bivalve tribe Coelaturini (Parreysiinae) at basin and continent-wide scales. Our results indicate that ORFs are efficiently captured without prior identification of intron-exon boundaries. The enrichment of UCEs was less successful, but nevertheless produced substantial data sets. Exploratory continent-wide phylogenetic analyses with ORF supercontigs (>515,000 parsimony informative sites) resulted in a fully resolved phylogeny, the backbone of which was also retrieved with UCEs (>11,000 informative sites). Variant calling on ORFs and UCEs of Coelaturini from the Malawi Basin produced ~2000 SNPs per population pair. Estimates of nucleotide diversity and population differentiation were similar for ORFs and UCEs. They were low compared to previous estimates in molluscs, but comparable to those in recently diversifying Malawi cichlids and other taxa at an early stage of speciation. Skimming off-target sequence data from the same enriched libraries of Coelaturini from the Malawi Basin, we reconstructed the maternally-inherited mitogenome, which displays the gene order inferred for the most recent common ancestor of Unionidae. Overall, our workflow and results provide exciting perspectives for integrative genomic studies of microevolutionary and macroevolutionary dynamics in non-model organisms.

Inhibitors of Nucleotide Biosynthesis as Candidates for a Wide Spectrum of Antiviral Chemotherapy.

Emerging and re-emerging viruses have been a challenge in public health in recent decades. Host-targeted antivirals (HTA) directed at cellular molecules or pathways involved in virus multiplication represent an interesting strategy to combat viruses presently lacking effective chemotherapy. HTA could provide a wide range of agents with inhibitory activity against current and future viruses that share similar host requirements and reduce the possible selection of antiviral-resistant variants. Nucleotide metabolism is one of the more exploited host metabolic pathways as a potential antiviral target for several human viruses. This review focuses on the antiviral properties of the inhibitors of pyrimidine and purine nucleotide biosynthesis, with an emphasis on the rate-limiting enzymes dihydroorotate dehydrogenase (DHODH) and inosine monophosphate dehydrogenase (IMPDH) for which there are old and new drugs active against a broad spectrum of pathogenic viruses.

KARRIKIN UPREGULATED F-BOX 1 negatively regulates drought tolerance in Arabidopsis.

The karrikin (KAR) receptor and several related signaling components have been identified by forward genetic screening, but only a few studies have reported on upstream and downstream KAR signaling components and their roles in drought tolerance. Here, we characterized the functions of KAR UPREGULATED F-BOX 1 (KUF1) in drought tolerance using a reverse genetics approach in Arabidopsis (Arabidopsis thaliana). We observed that kuf1 mutant plants were more tolerant to drought stress than wild-type (WT) plants. To clarify the mechanisms by which KUF1 negatively regulates drought tolerance, we performed physiological, transcriptome, and morphological analyses. We found that kuf1 plants limited leaf water loss by reducing stomatal aperture and cuticular permeability. In addition, kuf1 plants showed increased sensitivity of stomatal closure, seed germination, primary root growth, and leaf senescence to abscisic acid (ABA). Genome-wide transcriptome comparisons of kuf1 and WT rosette leaves before and after dehydration showed that the differences in various drought tolerance-related traits were accompanied by differences in the expression of genes associated with stomatal closure (e.g. OPEN STOMATA 1), lipid and fatty acid metabolism (e.g. WAX ESTER SYNTHASE), and ABA responsiveness (e.g. ABA-RESPONSIVE ELEMENT 3). The kuf1 mutant plants had higher root/shoot ratios and root hair densities than WT plants, suggesting that they could absorb more water than WT plants. Together, these results demonstrate that KUF1 negatively regulates drought tolerance by modulating various physiological traits, morphological adjustments, and ABA responses and that the genetic manipulation of KUF1 in crops is a potential means of enhancing their drought tolerance.

A KARRIKIN INSENSITIVE2 paralog in lettuce mediates highly sensitive germination responses to karrikinolide.

Karrikins (KARs) are chemicals in smoke that can enhance germination of many plants. Lettuce (Lactuca sativa) cv. Grand Rapids germinates in response to nanomolar karrikinolide (KAR1). Lettuce is much less responsive to KAR2 or a mixture of synthetic strigolactone analogs, rac-GR24. We investigated the molecular basis of selective and sensitive KAR1 perception in lettuce. The lettuce genome contains two copies of KARRIKIN INSENSITIVE2 (KAI2), which in Arabidopsis (Arabidopsis thaliana) encodes a receptor that is required for KAR responses. LsKAI2b is more highly expressed than LsKAI2a in dry achenes and during early stages of imbibition. Through cross-species complementation assays in Arabidopsis, we found that an LsKAI2b transgene confers robust responses to KAR1, but LsKAI2a does not. Therefore, LsKAI2b likely mediates KAR1 responses in lettuce. We compared homology models of KAI2 proteins from lettuce and a fire-follower, whispering bells (Emmenanthe penduliflora). This identified pocket residues 96, 124, 139, and 161 as candidates that influence the ligand specificity of KAI2. Further support for the importance of these residues was found through a broader comparison of pocket residues among 281 KAI2 proteins from 184 asterid species. Almost all KAI2 proteins had either Tyr or Phe identity at position 124. Genes encoding Y124-type KAI2 are more broadly distributed in asterids than in F124-type KAI2. Substitutions at residues 96, 124, 139, and 161 in Arabidopsis KAI2 produced a broad array of responses to KAR1, KAR2, and rac-GR24. This suggests that the diverse ligand preferences observed among KAI2 proteins in plants could have evolved through relatively few mutations.

Evaluación del canino maxilar permanente en niños entre 8 y 11 años en radiografía panorámica

RESUMEN: El canino maxilar permanente (CMP) es el segundo diente con mayor frecuencia de impactación debido a su largo descenso intraóseo y cronología de erupción. El objetivo de este estudio fue evaluar el grado de desarrollo dentario y posición del CMP entre los 8 años y los 11 años 11 meses con el fin de sugerir una edad cronológica óptima para su evaluación temprana en radiografía panorámica. Se realizó un estudio retrospectivo, en donde se analizaron 239 radiografías panorámicas de niños de 8 a 11 años. Éstas se agruparon según edad, género y área apical; luego se analizó el grado de desarrollo dentario y posición del vértice CMP izquierdo. En los resultados se observó que no existen diferencias significativas de la posición del CMP respecto a la edad cronológica. Además, entre los ocho años seis meses y nueve años seis meses un 61% de los caninos tuvieron más de la mitad de formación radicular. En conclusión, la evaluación temprana con radiografía panorámica del CMP se sugiere desde los ocho años seis meses a los nueve años seis meses, para alertar al clínico en casos donde el trayecto eruptivo se encuentre desviado.

ABSTRACT: The permanent maxillary canine (PMC) is the second most frequently impacted tooth due to its long intraosseous descent and eruption chronology. The objective of this study was to evaluate the degree of dental development and position of the PMC between the ages of 8 and 11 years 11 months in order to suggest an optimal chronological age for their early evaluation in panoramic radiography. A retrospective study was carried out, where 239 panoramic radiographs of children aged 8 to 11 years were analyzed. They were grouped according to age, gender and apical area; Then, the degree of dental development and position of the left PMC apex were analyzed. The results show that there are no significant differences in the position of the PMC with respect to chronological age. Furthermore, between eight years six months and nine years six months, 61% of the canines had more than half of the root formed. In conclusion, the early evaluation with panoramic radiography of the PMC is suggested from eight years six months to nine years six months, to alert the clinician in cases where the eruptive path is deviated.

KARRIKIN UP-REGULATED F-BOX 1 (KUF1) imposes negative feedback regulation of karrikin and KAI2 ligand metabolism in Arabidopsis thaliana.

SignificanceKarrikins are chemicals in smoke that stimulate regrowth of many plants after fire. However, karrikin responses are not limited to species from fire-prone environments and can affect growth after germination. Putatively, this is because karrikins mimic an unknown signal in plants, KAI2 ligand (KL). Karrikins likely require modification in plants to become bioactive. We identify a gene, KUF1, that appears to negatively regulate biosynthesis of KL and metabolism of a specific karrikin. KUF1 expression increases in response to karrikin or KL signaling, thus forming a negative feedback loop that limits further activation of the signaling pathway. This discovery will advance understanding of how karrikins are perceived and how smoke-activated germination evolved. It will also aid identification of the elusive KL.

[Prenatal diagnosis and early neonatal management of patients with hypoplastic left heart syndrome: Experience of a perinatal center]. / Diagnóstico prenatal y manejo neonatal precoz de pacientes con Síndrome de corazón izquierdo hipoplásico: Experiencia de un centro perinatal.

INTRODUCTION: Hypoplastic Left Heart Syndrome (HLHS) is the most common form of functional single-ventricle heart disease. Despite improvements in medical and surgical care, morbidity and mortality remain high, especially around the first surgical stage. OBJECTIVE: To describe the clinical characteristics of newborns with HLHS, seen at a perinatal referral center. PATIENTS AND METHOD: Retrospective des criptive study of all newborns with pre and/or postnatal diagnosis of HLHS between 2014 and 2019 in the Complejo Asistencial Dr. Sótero del Rio. Medical records were reviewed collecting demographic and perinatal variables, clinical evolution, mortality associated with the first surgery, and survival at one year. RESULTS: Nineteen patients were included. Most were term newborns and 13/19 were fema le. All had a prenatal diagnosis. Five patients had associated extracardiac anomalies. 16/19 required vasoactive drugs and 17/19 used invasive mechanical ventilation. Seven patients received enteral fe eding, without episodes of enterocolitis. The median age at transfer for surgery was 8 days. Thirteen patients underwent the Norwood procedure, with 31% of mortality, and 47% of survival at one year. CONCLUSIONS: Neonatal management of patients with HLHS is complex and the multidisciplinary approach is fundamental. Mortality around the first surgical stage of our cohort is greater than the international reports which could be influenced by the absence of fetal therapy and the higher inci dence of extracardiac malformations.

Antiviral bioactivity of resveratrol against Zika virus infection in human retinal pigment epithelial cells.

Resveratrol (RES) is a polyphenol with increasing interest for its inhibitory effects on a wide variety of viruses. Zika virus (ZIKV) is an arbovirus which causes a broad spectrum of ophthalmological manifestations in humans. Currently there is no certified therapy or vaccine to treat it, thus it has become a major global health threat. Retinal pigment epithelium (RPE) is highly permissive and susceptible to ZIKV. This work explored the protective effects of RES on ZIKV-infected human RPE cells. RES treatment resulted in a significant reduction of infectious viral particles in infected male ARPE-19 and female hTERT-RPE1 cells. This protection was positively influenced by the action of RES on mitochondrial dynamics. Also, docking studies predicted that RES has a high affinity for two enzymes of the rate-limiting steps of pyrimidine and purine biosynthesis and viral polymerase. This evidence suggests that RES might be a potential antiviral agent to treat ZIKV-induced ocular abnormalities.

Antiviral activity against Zika virus of a new formulation of curcumin in poly lactic-co-glycolic acid nanoparticles.

OBJECTIVES: In the search of an effective antiviral formulation, the natural product curcumin (CUR) was encapsulated into poly(lactic-co-glycolic acid) nanoparticles, a non-toxic bioresorbable and biocompatible copolymer. The resulting CUR containing particles (PLGA-CUR NPs) were characterized and analysed for antiviral activity against Zika virus (ZIKV) infection. METHODS: The PLGA-CUR NPs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic light scattering, scanning electron microscopy and thermogravimetric analysis and release profile. Cytotoxicity of PLGA-CUR and the antiviral activity against ZIKV were determined in Vero cells. The effect of PLGA-CUR NPs on viral RNA synthesis and protein expression was analysed by RT-qPCR and immunofluorescence staining, respectively. KEY FINDINGS: The PLGA-CUR NPs showed an appropriate in vitro drug release profile. Our studies of the antiviral activity of PLGA-CUR NPs and CUR against ZIKV by virus yield reduction as well as viral RNA synthesis and protein expression have shown that PLGA-CUR formulation is more effective than free CUR to inhibit ZIKV infection of Vero cells. CONCLUSIONS: Our results demonstrate for the first time the antiviral activity against ZIKV of PLGA nanoparticles charged with CUR, suggesting that PLGA-CUR NPs are promising candidates for a drug formulation against human pathogenic flaviviruses.

Development of a Reverse Genetic System to Generate Recombinant Chimeric Tacaribe Virus that Expresses Junín Virus Glycoproteins.

Mammarenaviruses are enveloped and segmented negative-stranded RNA viruses that comprise several pathogenic members associated with severe human hemorrhagic fevers. Tacaribe virus (TCRV) is the prototype for the New World group of mammarenaviruses and is not only naturally attenuated but also phylogenetically and antigenically related to all South American pathogenic mammarenaviruses, particularly the Junín virus (JUNV), which is the etiological agent of Argentinian hemorrhagic fever (AHF). Moreover, since TCRV protects guinea pigs and non-human primates from lethal challenges with pathogenic strains of JUNV, it has already been considered as a potential live-attenuated virus vaccine candidate against AHF. Here, we report the development of a reverse genetic system that relies on T7 polymerase-driven intracellular expression of the complementary copy (antigenome) of both viral S and L RNA segments. Using this approach, we successfully recovered recombinant TCRV (rTCRV) that displayed growth properties resembling those of authentic TCRV. We also generated a chimeric recombinant TCRV expressing the JUNV glycoproteins, which propagated similarly to wild-type rTCRV. Moreover, a controlled modification within the S RNA 5' non-coding terminal sequence diminished rTCRV propagation in a cell-type dependent manner, giving rise to new perspectives where the incorporation of additional attenuation markers could contribute to develop safe rTCRV-based vaccines against pathogenic mammarenaviruses.

Effect of Drying Methods on Lutein Content and Recovery by Supercritical Extraction from the Microalga Muriellopsis sp. (MCH35) Cultivated in the Arid North of Chile.

In this study, we determined the effect of drying on extraction kinetics, yield, and lutein content and recovery of the microalga Muriellopsis sp. (MCH35) using the supercritical fluid extraction (SFE) process. The strain was cultivated in an open-raceways reactor in the presence of seawater culture media and arid outdoor conditions in the north of Chile. Spray-drying (SD) and freeze-drying (FD) techniques were used for dehydrating the microalgal biomass. Extraction experiments were performed by using Box-Behnken designs, and the parameters were studied: pressure (30-50 MPa), temperature (40-70 °C), and co-solvent (0-30% ethanol), with a CO2 flow rate of 3.62 g/min for 60 min. Spline linear model was applied in the central point of the experimental design to obtain an overall extraction curve and to reveal extraction kinetics involved in the SFE process. A significant increase in all variables was observed when the level of ethanol (15-30% v/v) was increased. However, temperature and pressure were non-significant parameters in the SFE process. The FD method showed an increase in lutein content and recovery by 0.3-2.5-fold more than the SD method. Overall, Muriellopsis sp. (MCH35) is a potential candidate for cost-effective lutein production, especially in desert areas and for different biotechnological applications.

Diversification dynamics of freshwater bivalves (Unionidae: Parreysiinae: Coelaturini) indicate historic hydrographic connections throughout the East African Rift System.

Invertebrates are exceptionally diverse, but many are in decline because of anthropogenic changes to their habitat. This situation is particularly problematic for taxa that are not well monitored or taxonomically poorly understood, because the lack of knowledge hampers conservation. Despite their important functional role in freshwater ecosystems, African bivalves of the family Unionidae remain poorly studied compared to their highly threatened relatives in Europe, the U.S.A. and Canada. To resolve relationships and to study diversification dynamics in space and time, we performed time-calibrated phylogenetic studies and biogeographical modeling on the unionids from the East African Rift System and surroundings, including representatives of all currently recognized Afrotropical genera except for Brazzaea (and Unio from southern Africa). Our analyses indicate that all sampled Afrotropical unionids belong to the tribe Coelaturini (subfamily Parreysiinae), as does the genus Moncetia from Lake Tanganyika, which is currently attributed to the family Iridinidae. Colonization of Africa from Eurasia by Parreysiinae occurred ~17 Ma ago, and the subsequent diversification of Coelaturini in Africa continued at a steady pace, although net diversification decreased over time as more niches and ecoregions became occupied. Clades in Coelaturini largely reflect drainage basins, with the oldest lineages and highest regional diversity occurring in Lake Tanganyika, followed by the Congo Basin watershed in general. The species assemblage of Lake Tanganyika reflects multiple independent events of colonization and intralacustrine diversification since the Late Miocene or Early Pliocene. The clades of other regions, including that containing the species from Lake Malawi, are comparatively young. Biogeographical analyses indicate that the colonization history was mainly driven by cladogenesis in sympatry, whereas few anagenetic events contributed to the modern distribution of Coelaturini. Ancestral range estimations demonstrate that Coelaturini originated in the Victoria and/or Tanganyika ecoregions, and that the Congo Basin played an essential role in the colonization of Africa by Coelaturini.

Adaptive divergence in shell morphology in an ongoing gastropod radiation from Lake Malawi.

BACKGROUND: Ecological speciation is a prominent mechanism of diversification but in many evolutionary radiations, particularly in invertebrates, it remains unclear whether supposedly critical ecological traits drove or facilitated diversification. As a result, we lack accurate knowledge on the drivers of diversification for most evolutionary radiations along the tree of life. Freshwater mollusks present an enigmatic example: Putatively adaptive radiations are being described in various families, typically from long-lived lakes, whereas other taxa represent celebrated model systems in the study of ecophenotypic plasticity. Here we examine determinants of shell-shape variation in three nominal species of an ongoing ampullariid radiation in the Malawi Basin (Lanistes nyassanus, L. solidus and Lanistes sp. (ovum-like)) with a common garden experiment and semi-landmark morphometrics. RESULTS: We found significant differences in survival and fecundity among these species in contrasting habitats. Morphological differences observed in the wild persisted in our experiments for L. nyassanus versus L. solidus and L. sp. (ovum-like), but differences between L. solidus and L. sp. (ovum-like) disappeared and re-emerged in the F1 and F2 generations, respectively. These results indicate that plasticity occurred, but that it is not solely responsible for the observed differences. Our experiments provide the first unambiguous evidence for genetic divergence in shell morphology in an ongoing freshwater gastropod radiation in association with marked fitness differences among species under controlled habitat conditions. CONCLUSIONS: Our results indicate that differences in shell morphology among Lanistes species occupying different habitats have an adaptive value. These results also facilitate an accurate reinterpretation of morphological variation in fossil Lanistes radiations, and thus macroevolutionary dynamics. Finally, our work testifies that the shells of freshwater gastropods may retain signatures of adaptation at low taxonomic levels, beyond representing an evolutionary novelty responsible for much of the diversity and disparity in mollusks altogether.

The impact of secondary forest regeneration on ground-dwelling ant communities in the Tropical Andes.

Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants play crucial roles in ecosystem functioning, and a key question is how time since abandonment and elevation (and inherent temperature gradients therein) affect patterns of ant recovery within secondary forest systems. Focusing on the Colombian Andes across a 1300 m altitudinal gradient and secondary forest (2-30 years) recovering on abandoned cattle pastures, we find that over time ant community composition and species richness recovered towards that of primary forest. However, these relationships are strongly dependent on elevation with the more open and warmer pasturelands supporting more ants than either primary or secondary forest at a particular elevation. The loss of species richness and change in species composition with elevation is less severe in pasture than forests, suggesting that conditions within pasture and its remaining scattered trees, hedgerows and forest fragments, are more favourable for some species, which are likely in or near thermal debt. Promoting and protecting natural regenerating forests over the long term in the montane tropics will likely offer significant potential for returning ant communities towards primary forest levels.