Analysis of Moon impact flashes detected during the 2012 and 2013 Perseids

We present the results of our Moon impact flashes detection campaigns performed around the maximum activity period of the Perseid meteor shower in 2012 and 2013. Just one flash produced by a Perseid meteoroid was detected in 2012 because of very unfavourable geometric conditions, but 12 of these were confirmed in 2013. The visual magnitude of the flashes ranged between 6.6 and 9.3. A luminous efficiency of 1.8 $\times$ 10$^{-3}$ has been estimated for meteoroids from this stream. According to this value, impactor masses would range between 1.9 and 190 g. In addition, we propose a criterion to establish, from a statistical point of view, the likely origin of impact flashes recorded on the lunar surface.Comment: Accepted for publication in Astronomy and Astrophysics on March 11, 201

Effects of disease activity on lipoprotein levels in patients with early arthritis: can oxidized LDL cholesterol explain the lipid paradox theory?

Background An increased risk of cardiovascular (CV) complications has been described in patients with rheumatoid arthritis (RA). It is the result of the combined effect of classic CV risk factors and others that are specific to the disease. Methods We assessed data from 448 early arthritis (EA) patients: 79% women, age (median [p25-p75]) at onset: 55 [44?67] years and disease duration at study entry 5 [3?8] months; and 72% fulfilled the 1987 RA criteria at 2?years of follow-up. Rheumatoid factor was positive in 54% of patients and anti-citrullinated peptide antibodies in 50%. The follow-up of patients ranged from 2 to 5?years with more than 1400 visits with lipoprotein measurements available (mean 2.5 visits/patient). Demographic- and disease-related variables were systematically recorded. Total cholesterol (TC), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C) levels were obtained from routine laboratory tests. Oxidized-LDL (oxLDL-C) levels were assessed using a commercial ELISA kit. We fitted population-averaged models nested by patient and visit to determine the effect of independent variables on serum levels of TC, its fractions, and oxLDL-C. Results After adjustment for several confounders, high-disease activity was significantly associated with decreased TC, HDL-C, and LDL-C levels and increased oxLDL-C levels. Standardized coefficients showed that the effect of disease activity was greater on oxLDL-C and HDL-C. Interestingly, we observed that those patients with lower levels of LDL-C showed higher oxLDL-C/LDL-C ratios. Conclusions High-disease activity in EA patients results in changes in the HDL-C and oxLDL-C levels, which in turn may contribute to the increased risk of CV disease observed in these patients.Our manuscript was supported by grants RD16/0011/0012, RD16/0011/0009, RD16/0011/0004, PI05/2044, and PI18/0371 from the Ministerio de Economía y Competitividad (Instituto de Salud Carlos III) and co-funded by Fondo Europeo de Desarrollo Regional (FEDER)

Global analysis of the sugarcane microtranscriptome reveals a unique composition of small RNAs associated with axillary bud outgrowth

Axillary bud outgrowth determines shoot architecture and is under the control of endogenous hormones and a fine-tuned gene-expression network, which probably includes small RNAs (sRNAs). Although it is well known that sRNAs act broadly in plant development, our understanding about their roles in vegetative bud outgrowth remains limited. Moreover, the expression profiles of microRNAs (miRNAs) and their targets within axillary buds are largely unknown. Here, we employed sRNA next-generation sequencing as well as computational and gene-expression analysis to identify and quantify sRNAs and their targets in vegetative axillary buds of the biofuel crop sugarcane (Saccharum spp.). Computational analysis allowed the identification of 26 conserved miRNA families and two putative novel miRNAs, as well as a number of trans-acting small interfering RNAs. sRNAs associated with transposable elements and protein-encoding genes were similarly represented in both inactive and developing bud libraries. Conversely, sequencing and quantitative reverse transcription-PCR results revealed that specific miRNAs were differentially expressed in developing buds, and some correlated negatively with the expression of their targets at specific stages of axillary bud development. For instance, the expression patterns of miR159 and its target GAMYB suggested that they may play roles in regulating abscisic acid-signalling pathways during sugarcane bud outgrowth. Our work reveals, for the first time, differences in the composition and expression profiles of diverse sRNAs and targets between inactive and developing vegetative buds that, together with the endogenous balance of specific hormones, may be important in regulating axillary bud outgrowth

Porous Titanium surfaces to control bacteria growth: mechanical properties and sulfonated polyetheretherketone coating as antibiofounling approaches

Here, titanium porous substrates were fabricated by a space holder technique. The relationship between microstructural characteristics (pore equivalent diameter, mean free-path between pores, roughness and contact surface), mechanical properties (Young’s modulus, yield strength and dynamic micro-hardness) and bacterial behavior are discussed. The bacterial strains evaluated are often found on dental implants: Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. The colony-forming units increased with the size of the spacer for both types of studied strains. An antibiofouling synthetic coating based on a sulfonated polyetheretherketone polymer revealed an effective chemical surface modification for inhibiting MRSA adhesion and growth. These findings collectively suggest that porous titanium implants designed with a pore size of 100–200 µm can be considered most suitable, assuring the best biomechanical and bifunctional anti-bacterial properties.University of Seville VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

Balancing porosity and mechanical properties of titanium samples to favor cellular growth against bacteria

Two main problems limit the success of titanium implants: bacterial infection, which restricts their osseointegration capacity; and the stiffness mismatch between the implant and the host cortical bone, which promotes bone resorption and risk of fracture. Porosity incorporation may reduce this difference in stiffness but compromise biomechanical behavior. In this work, the relationship between the microstructure (content, size, and shape of pores) and the antibacterial and cellular behavior of samples fabricated by the space-holder technique (50 vol % NH4HCO3 and three ranges of particle sizes) is established. Results are discussed in terms of the best biomechanical properties and biofunctional activity balance (cell biocompatibility and antibacterial behavior). All substrates achieved suitable cell biocompatibility of premioblast and osteoblast in adhesion and proliferation processes. It is worth to highlighting that samples fabricated with the 100–200 μm space-holder present better mechanical behavior—in terms of stiffness, microhardness, and yield strength—which make them a very suitable material to replace cortical bone tissues. Those results exposed the relationship between the surface properties and the race of bacteria and mammalian cells for the surface with the aim to promote cellular growth over bacteria.University of Seville (Spain) VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

Dynamic Capabilities in Information Systems Research: A Critical Review, Synthesis of Current Knowledge, and Recommendations for Future Research

Over the past twenty years, the dynamic capabilities view (DCV) has gained prominence in the IS field as a theoretical perspective from which to explain competitive advantage in turbulent environments. While there are quite a few review studies of dynamic capabilities (DCs) in the strategic management domain, research on DCs in the IS area has not been synthesized nor critically analyzed. The result is that the role that IT plays in the DCV remains largely ambiguous, and the way we think and conduct IS research on DCs is unquestioned. Addressing this, we conducted a critical review of DCs in IS research based on 136 papers. Our review provides a synthesis of contemporary knowledge on DCs that emphasizes the role of IT in this research, and a critical analysis of the assumptions underlying this literature. In addition, we develop a minimum DC definition for future research as a solution to the conceptual issues that we uncovered via the critical analysis. We further leverage the remaining findings of our critical review by providing a detailed research agenda for future investigations on DCs by IS scholars

Porous titanium substrates coated with a bilayer of bioactive glasses

Porous titanium substrates coated by dripping-sedimentation technique with a novel bilayer of (45S5 / 1393) bioactive glasses are proposed to overcome some limitations of the use of titanium for implants, such as the stress shielding and the poor osseointegration. Composition, thickness, roughness and micromechanical behavior (P-h curves) of the coating and the influence of the porous titanium substrates have been characterized. Best results were found for the substrate with 30 vol.% of porosity and a range size of 355 ‒ 500 μm, since it enhanced the mechanical and biofunctional behavior, due to the good adhesion of the 1393 bioglass to the substrate and the greater bioactivity of the 45S5 bioglass, which would be in contact with the bone.Junta de Andalucía–FEDER (Spain) US-1259771M.E.C. (Spain) 2004/00001203 (RYC-2004-001497

Developmental Sex Differences in the Metabolism of Cardiolipin in Mouse Cerebral Cortex Mitochondria

Cardiolipin (CL) is a mitochondrial-specific phospholipid. CL content and acyl chain composition are crucial for energy production. Given that estradiol induces CL synthesis in neurons, we aimed to assess CL metabolism in the cerebral cortex (CC) of male and female mice during early postnatal life, when sex steroids induce sex-dimorphic maturation of the brain. Despite the fact that total amount of CL was similar, its fatty acid composition differed between males and females at birth. In males, CL was more mature (lower saturation ratio) and the expression of the enzymes involved in synthetic and remodeling pathways was higher, compared to females. Importantly, the sex differences found in CL metabolism were due to the testosterone peak that male mice experience perinatally. These changes were associated with a higher expression of UCP-2 and its activators in the CC of males. Overall, our results suggest that the perinatal testosterone surge in male mice regulates CL biosynthesis and remodeling in the CC, inducing a sex-dimorphic fatty acid composition. In male's CC, CL is more susceptible to peroxidation, likely explaining the testosterone-dependent induction of neuroprotective molecules such as UCP-2. These differences may account for the sex-dependent mitochondrial susceptibility after perinatal hypoxia/ischemia.Instituto de Investigaciones Bioquímicas de La Plat

Biofunctional and Tribo-mechanical Behavior of Porous Titanium Substrates Coated with a Bioactive Glass Bilayer (45S5 ‒ 1393)

Porous substrates of commercially pure titanium have been coated with a novel bilayer of bioactive glasses, 45S5 and 1393, to improve the osseointegration and solve the stress-shielding phenomenon of titanium partial implants. The porosity of the substrates, the scratch resistance and bioactivity of the coating have been evaluated. Results are discussed in terms of stiffness and yield strength of the substrates, as well as the chemical composition, thickness and design of the bioglass coating (monolithic vs. bilayer). The role of the pores was a crucial issue in the anchoring of the coating, both in porosity percentage (30 and 60 vol. %) and pore range size (100 – 200 and 355 ‒ 500 μm). The study was focused on the adhesion and infiltration of a 1393 bioglass layer (in contact with a porous titanium substrate), in combination with the biofunctionality of the 45S5 bioglass layer (surrounded by the host bone tissue), as 1393 bioglass enhances the adherence, while 45S5 bioglass promotes higher bioactivity. This bioactivity of the raw powder was initially estimated by nuclear magnetic resonance, through the evaluation of the chemical environments, and confirmed by the formation of hydroxyapatite, when immersed in simulated body fluid. Results revealed that the substrate with 30 vol. % of porosity and a range of 355 ‒ 500 μm pore size, coated with this novel bioactive glass bilayer, presented the best combination in terms of mechanical and biofunctional properties.Junta de Andalucía–FEDER (Spain) Project Ref. US-1259771Ministerio de Ciencia y Educación (Spain) Project 2004/00001203 (RYC-2004-001497