Invasive species and habitat degradation in Iberian streams: An analysis of their role in freshwater fish diversity loss

Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions

Phage Ø29 Protein p6 Is in a Monomer−Dimer Equilibrium That Shifts to Higher Association States at the Millimolar Concentrations Found in Vivo

Protein p6 from Bacillus subtilis phage Ø29 (Mr = 11 800) binds in vitro to DNA forming a large nucleoprotein complex in which the DNA wraps a multimeric protein core. The high intracellular abundance of protein p6 together with its ability to bind the whole Ø29 DNA in vitro strongly suggests that it plays a role in viral genome organization. We have determined by sedimentation equilibrium analysis that protein p6 (1−100 μM range), in the absence of DNA, is in a monomer−dimer equilibrium, with an association constant (K2) of 2 × 105 M-1. The intracellular concentration of protein p6 (1 mM) was estimated measuring the number of copies per cell (7 × 105) and the cell volume (1 × 10-15 L). At concentrations around 1 mM, protein p6 associates into oligomers. This self-association behavior is compatible with a dimer−hexamer model (K2,6 = 3.2 × 108 M-2) or with an isodesmic association of the dimer (K = 950 M-1), because the apparent weight-average molecular mass (Mw,a) does not reach saturation at the highest protein concentrations. The sedimentation coefficients of protein p6 monomer and dimer were 1.4 and 2.0, respectively, compatible with translational frictional ratios (f/fo) of 1.15 and 1.30, which slightly deviate from the hydrodynamics of a rigid globular protein. Taking together these results and considering the structure of the nucleoprotein complex, we speculate that the observed oligomers of protein p6 could mimic a scaffold on which DNA folds to form the nucleoprotein complex in vivo.Peer reviewe

Collision of protostellar jets in the star-forming region IC 1396N: Analysis of knot proper motions

Context. The bright-rimmed cloud IC 1396N is believed to host one of the few known cases where two bipolar CO outflows driven by young stellar objects collide. The CO outflows are traced by chains of knots of H2 emission, with enhanced emission at the position of the possible collision. Aims. The aim of this work is to use the proper motions of the H2 knots to confirm the collision scenario. Methods. A second-epoch H2 image was obtained, and the proper motions of the knots were determined with a time baseline of ∼11 yr. We also performed differential photometry on the images to check the flux variability of the knots. Results. For each outflow (N and S), we classified the knots as pre-collision or post-collision. The axes of the pre-collision knots, the position of the possible collision point, and the axes of the post-collision knots were estimated. The difference between the proper motion direction of the post-collision knots and the position angle from the collision point was also calculated. For some of the knots, we obtained the 3D velocity using the radial velocity derived from H2 spectra. Conclusions. The velocity pattern of the H2 knots in the area of interaction (post-collision knots) shows a deviation from that of the pre-collision knots, consistent with being a consequence of the interaction between the two outflows. This favours the interpretation of the IC 1396N outflows as a true collision between two protostellar jets instead of a projection effect

Lipid nanoparticles for alkyl lysophospholipid edelfosine encapsulation: development and in vitro characterization

The ether lipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine, edelfosine (ET-18-OCH3) is the prototype molecule of a promising class of antitumour drugs named alkyl–lysophospholipid analogues (ALPs) or antitumor ether lipids. This drug presents a very important drawback as can be the dose depending haemolysis when administered intravenously. Lipid nanoparticles have been lately proposed for different drug encapsulation as an alternative to other controlled release delivery systems, such as liposomes or polymeric nanoparticles. The aim of this study was to develop a lipid nanoparticulate system that would decrease systemic toxicity as well as improve the therapeutic potential of the drug. Lipids employed were Compritol® 888 ATO and stearic acid. The nanoparticles were characterized by photon correlation spectroscopy for size and size distribution, and atomic force microscopy (AFM) was used for the determination of morphological properties. By both differential scanning calorimetry (DSC) and X-ray diffractometry, crystalline behaviour of lipids and drug was assessed. The drug encapsulation efficiency and the drug release kinetics under in vitro conditions were measured by HPLC–MS. It was concluded that Compritol® presents advantages as a matrix material for the manufacture of the nanoparticles and for the controlled release of edelfosine

Disulfide Engineered Lipase to Enhance the Catalytic Activity: A Structure-Based Approach on BTL2

Enhancement, control, and tuning of hydrolytic activity and specificity of lipases are major goals for the industry. Thermoalkaliphilic lipases from the I.5 family, with their native advantages such as high thermostability and tolerance to alkaline pHs, are a target for biotechnological applications. Although several strategies have been applied to increase lipases activity, the enhancement through protein engineering without compromising other capabilities is still elusive. Lipases from the I.5 family suffer a unique and delicate double lid restructuration to transition from a closed and inactive state to their open and enzymatically active conformation. In order to increase the activity of the wild type Geobacillus thermocatenulatus lipase 2 (BTL2) we rationally designed, based on its tridimensional structure, a mutant (ccBTL2) capable of forming a disulfide bond to lock the open state. ccBTL2 was generated replacing A191 and F206 to cysteine residues while both wild type C64 and C295 were mutated to serine. A covalently immobilized ccBTL2 showed a 3.5-fold increment in esterase activity with 0.1% Triton X-100 (2336 IU mg-1) and up to 6.0-fold higher with 0.01% CTAB (778 IU mg-1), both in the presence of oxidizing sulfhydryl agents, when compared to BTL2. The remarkable and industrially desired features of BTL2 such as optimal alkaliphilic pH and high thermal stability were not affected. The designed disulfide bond also conferred reversibility to the enhancement, as the increment on activity observed for ccBTL2 was controlled by redox pretreatments. MD simulations suggested that the most stable conformation for ccBTL2 (with the disulfide bond formed) was, as we predicted, similar to the open and active conformation of this lipase.Financial and logistic support from Colombian Universidad del Valle and COLCIENCIAS (CI 71083-Grant 745-2016-Project 110671250425), Spanish CICYT project BIO-2005-6018576, BFU2017-90030-P, and BFU2011-25326, B. Di G. In addition, thanks to the Spanish MINECO for a FPU fellowship.S

Ideal cardiovascular health and incident cardiovascular disease among adults: a systematic review and meta-analysis

Objective: To investigate the association between ideal cardiovascular health (CVH) metrics and incident cardiovascular disease (CVD) by conducting a systematic review and meta-analysis of prospective cohort studies. Methods: The MEDLINE, EMBASE, and CINAHL databases were searched from January 1, 2010 through July 31, 2017, for studies that met the following criteria: (1) prospective studies conducted in adults, (2) with outcome data on CVD incidence and (3) a measure of ideal CVH metrics. Results: Twelve studies (210,443 adults) were included in this analysis. Compared with adults who met 0 to 2 of the ideal CVH metrics (high-risk individuals), a significantly lower hazard for CVD incidence was observed in those who had 3 to 4 points for the ideal CVH metrics (hazard ratio [HR]=0.53; 95% CI, 0.47-0.59) and 5 to 7 points (HR=0.28; 95% CI, 0.23-0.33). Weaker associations were observed in studies with older individuals, suggesting that there is a positive relationship between age and HR. Conclusion: Although meeting 5 to 7 metrics is associated with the lowest hazard for CVD incidence, meeting 3 to 4 metrics still offers an important protective effect for CVD. Therefore, a realistic goal in the general population in the short term could be to promote at least an intermediate ideal CVH profile (3 to 4 metrics)

The Use of Video-Gaming Devices as a Motivation for Learning Embedded Systems Programming

As embedded systems are becoming prevalent in everyday life, many universities are incorporating embedded systems-related courses in their undergraduate curricula. However, it is not easy to motivate students in such courses, since they conceive of embedded systems as bizarre computing elements, different from the personal computers with which they are familiar. This problem has been overcome at the University of Granada, Spain, by taking advantage of the connection many students have with video games.Spanish CICYT Project SAF2010-20558University of Granada Innovative Teaching Project 04-03-0

Ultra high performance liquid chromatography–tandem mass spectrometry method for cyclosporine a quantification in biological samples and lipid nanosystems

Cyclosporine A (CyA) is an immunosuppressant cyclic undecapeptide used for the prevention of organ transplant rejection and in the treatment of several autoimmune disorders. An ultra high performance liquid chromatography–tandem mass spectrometry method (UHPLC–MS/MS) to quantify CyA in lipid nanosystems and mouse biological matrices (whole blood, kidneys, lungs, spleen, liver, heart, brain, stomach and intestine) was developed and fully validated. Chromatographic separation was performed on an Acquity UPLC® BEH C18 column with a gradient elution consisting of methanol and 2 mM ammonium acetate aqueous solution containing 0.1% formic acid at a flow rate of 0.6 mL/min. Amiodarone was used as internal standard (IS). Retention times of IS and CyA were 0.69 min and 1.09 min, respectively. Mass spectrometer operated in electrospray ionization positive mode (ESI+) and multiple reaction monitoring (MRM) transitions were detected, m/z 1220.69 → 1203.7 for CyA and m/z 646 → 58 for IS. The extraction method from biological samples consisted of a simple protein precipitation with 10% trichloroacetic acid aqueous solution and acetonitrile and 5 μL of supernatant were directly injected into the UHPLC–MS/MS system. Linearity was observed between 0.001 μg/mL–2.5 μg/mL (r ≥ 0.99) in all matrices. The precision expressed in coefficient of variation (CV) was below 11.44% and accuracy in bias ranged from −12.78% to 7.99% including methanol and biological matrices. Recovery in all cases was above 70.54% and some matrix effect was observed. CyA was found to be stable in post-extraction whole blood and liver homogenate samples exposed for 6 h at room temperature and 72 h at 4 °C. The present method was successfully applied for quality control of lipid nanocarriers as well as in vivo studies in BALB/c mice