Maltrato infantil y representaciones de apego: defensas, memoria y estrategias, una revisión

Rodriguez, AF (Fresno Rodriguez, Andres); Contreras, RS (Spencer Contreras, Rosario); Castro, TR (Retamal Castro, Tania). Univ Talca, Fac Psicol, Talca, Chile.The aim of this paper is a review of the literature about the influence of child abuse on the formation of attachment representations. It describes the main theoretical assumptions about the effects of abuse on the defensive processes, memory systems and attachment strategies. These elements are discussed trough the presentation of an integrative model which is contrasted with empirical studies. It shows that child abuse affects the quality of attachment representations; however the studies do not take in to account all the complexity of the phenomenon of abuse. Theoretical issues discussed in this paper are marginally tested in the research reported

Adsorption of fluorobenzene onto granular activated carbon: Isotherm and bioavailability studies

The adsorption of a recalcitran fluoroaromatic compound, fluorobenzene (FB), onto granular activated carbon (GAC) was evaluated. The respective isotherm was obtained and the Langmuir, Freundlich and Redlich–Peterson models were fitted to the experimental data, with the Redlich–Peterson model giving the best fitting. Freundlich model also provided a good fit but the Langmuir model could not adequately fit the experimental data, especially at high FB concentrations. Maximal adsorption capacity of FB onto GAC was foundto be 388 mg of FB per gram of GAC. The reversibility of the adsorption of FB onto GAC was investigated, both in the absence and presence of microorganisms. Abiotic desorption of FB occurred to a small extent (between 3% and 22%, for amounts of FB initially adsorbed to the GAC between 37 and 388 mg g 1), and bioregeneration of GAC was shown to occur when the matrix was exposed to a FB degrading culture, with 58–80% of the adsorbed FB being biodegraded. A residual amount of FB showed not to be bioavailable, suggesting that part of the adsorbed FB may be irreversibly bound. The fraction of the non-bioavailable FB increased at higher amounts of adsorbed FB, from 19% to 33%. The results indicate that the GAC employed in this study has a good capacity to adsorb FB and that bioregeneration of this matrix is a feasible process

Structural studies on the H3 influenza A virus haemagglutinin : Receptor binding and membrane fusion.

In this project, the receptor binding and membrane fusion activities of the membrane-anchored glycoprotein haemagglutinin (HA), H3 subtype, of the influenza A virus were studied. Influenza viruses from different hosts can distinguish between a.2-3 and a2-6 linkages that sialic acid (Sia) forms with the penultimate saccharide residue of the receptor. Human viruses prefer a2-6 linkages and avian viruses ct2-3 linkages. The side chain of residue 226 of the HA receptor binding site (RBS) is involved in the specific recognition of those linkages. The HA of the 1968 Hong Kong (HK) pandemic virus (H3 subtype), contained in the recombinant X-31 virus, has a 226-leucine and prefers binding to a2-6 linkages. The L226Q HA of the variant virus X-31/horse serum (X-31/HS), corresponding to a single-site mutant of the X-31 HA having 226-glutamine, prefers a2-3 linkages. To define the molecular interactions of the L226Q HA with the virus receptor, the crystal structures of L226Q HA in complex with the receptor analogues lactoseries tetrasaccharide a (LSTa), a2-3-terminated, and lactoseries tetrasaccharide c (LSTc), a2-6-terminated, were determined. The structures show the saccharide residues Sia and galactose (Gal) of LSTa and only the Sia of LSTc bound on the L226Q HA RBS, which correlates with the higher affinity of L226Q HA for the ct2-3 linkage. However, the L226Q HA binds both the trans and cis configurations of the Sia-Gal glycosidic bond of LSTa, which has never been observed before. These results are discussed in comparison with data from binding assays and the available crystal structures of the X-31 HA, the H3 avian HA of the influenza virus A/duck/Ukraine/63, a potential precursor of the 1968 HK pandemic virus, and other HAs, of different subtypes and hosts of origin, in complex with LSTa and LSTc. Upon endocytosis, at the low endosomal pH, the HA undergoes an irreversible conformational change associated with the fusion of the viral and endosomal membranes, a process by which the virus enters the target cell. To gain further insights into the membrane fusion mechanism catalysed by the influenza HA, the purification and crystallisation trials of three different X-31 HA forms representative of the neutral pH and fusion pH-induced conformations, containing the membrane-interacting segments fusion peptide and transmembrane anchor, were carried out with the future aim of their crystal structure determination. The procedures for the purification and crystallisation trials of the X-31 HA proteins in different conformations are discussed in the context of the general purification and crystallisation of membrane proteins. No promising hint has yet been obtained in the crystallisation trials

Contact resistance in graphene-based devices

We report a systematic study of the contact resistance present at the interface between a metal (Ti) and graphene layers of different, known thickness. By comparing devices fabricated on 11 graphene flakes we demonstrate that the contact resistance is quantitatively the same for single-, bi-, and tri-layer graphene ($\sim800 \pm 200 \Omega \mu m$), and is in all cases independent of gate voltage and temperature. We argue that the observed behavior is due to charge transfer from the metal, causing the Fermi level in the graphene region under the contacts to shift far away from the charge neutrality point

Bacterial community dynamics in horizontal flow constructed wetlands with different plants for high salinity industrial wastewater polishing

This study is focused on the diversity of bacterial communities from two series of horizontal subsurface flow constructed wetlands (CW) polishing high salinity tannery wastewater. Each series was planted with Arundo donax or Sarcocornia sp. in a substrate composed by expanded clay and sand. Chemical and biochemical oxygen demand removal efficiencies were similar in each series, varying between 58 and 67% (inlet COD 218 ± 28 mg L−1) and 60 and 77% (inlet BOD5 37 ± 6 mg L−1), respectively. High numbers of culturable bacteria were obtained from substrate and root samples – 5.75 × 106-3.95 × 108 CFU g−1 recovered on marine agar and 1.72 × 107-8.46 × 108 CFU g−1 on nutrient agar. Fifty bacterial isolates were retrieved from the CW, related phylogenetically to Firmicutes, Actinobacteria, Bacteroidetes, α-, β-, and γ-Proteobacteria. Changes in the bacterial communities, from roots and substrate of each series, related to the plant species, hydraulic loading rates and along CW operation were examined using denaturating gradient gel electrophoresis (DGGE). The clustering analysis suggested that a diverse and distinct bacterial community inhabits each series, which was related to the type of plant present in each CW.info:eu-repo/semantics/publishedVersio

Random amplification of polymorphic DNA reveals clonal relationships among enteropathogenic Escherichia coli isolated from non-human primates and humans

Enteropathogenic Escherichia coli ( EPEC) strains are important agents of infantile diarrhea all over the world, gaining even greater importance in developing countries. EPEC have also been isolated from various animal species, but most isolates belong to serotypes that differ from those recovered from humans. However, it has been demonstrated that several isolates from non- human primates belong to the serogroups and/ or serotypes related to those implicated in human disease. The objective of this study was to evaluate the genetic differences between thirteen strains isolated from non- human primates and the same number of strains isolated from human infections. Human isolates belonged to the same serogroup/ serotype as the monkey strains and the evaluation was done by analysis of random amplified polymorphic DNA. Dendrogram analysis showed that there was no clustering between human and monkey strains. Human and non- human isolates of the EPEC serotypes O127:H40 and O128:H2 shared 90 and 87% of their bands, respectively, indicating strong genomic similarity between the strains, leading to the speculation that they may have arisen from the same pathogenic clone. To our knowledge, this study is the first one comparing genomic similarity between human and non- human primate strains and the results provide further evidence that monkey EPEC strains correlate with human EPEC, as suggested in a previous investigation

Cytosolic NUAK1 Enhances ATP Production by Maintaining Proper Glycolysis and Mitochondrial Function in Cancer Cells

Indexación: Scopus.NUAK1 is an AMPK-related kinase located in the cytosol and the nucleus, whose expression associates with tumor malignancy and poor patient prognosis in several cancers. Accordingly, NUAK1 was associated with metastasis because it promotes cell migration and invasion in different cancer cells. Besides, NUAK1 supports cancer cell survival under metabolic stress and maintains ATP levels in hepatocarcinoma cells, suggesting a role in energy metabolism in cancer. However, the underlying mechanism for this metabolic function, as well as its link to NUAK1 subcellular localization, is unclear. We demonstrated that cytosolic NUAK1 increases ATP levels, which associates with increased mitochondrial respiration, supporting that cytosolic NUAK1 is involved in mitochondrial function regulation in cancer cells. NUAK1 inhibition led to the formation of “donut-like” structures, providing evidence of NUAK1-dependent mitochondrial morphology regulation. Additionally, our results indicated that cytosolic NUAK1 increases the glycolytic capacity of cancer cells under mitochondrial inhibition. Nuclear NUAK1 seems to be involved in the metabolic switch to glycolysis. Altogether, our results suggest that cytosolic NUAK1 participates in mitochondrial ATP production and the maintenance of proper glycolysis in cancer cells. Our current studies support the role of NUAK1 in bioenergetics, mitochondrial homeostasis, glycolysis and metabolic capacities. They suggest different metabolic outcomes depending on its subcellular localization. The identified roles of NUAK1 in cancer metabolism provide a potential mechanism relevant for tumor progression and its association with poor patient prognosis in several cancers. Further studies could shed light on the molecular mechanisms involved in the identified metabolic NUAK1 functions. © Copyright © 2020 Escalona, Muñoz, Pincheira, Elorza and Castro.https://www.frontiersin.org/articles/10.3389/fonc.2020.01123/ful

Dynamics of a Dirac Fermion in the presence of spin noncommutativity

Recently, it has been proposed a spacetime noncommutativity that involves spin degrees of freedom, here called "spin noncommutativity". One of the motivations for such a construction is that it preserves Lorentz invariance, which is deformed or simply broken in other approaches to spacetime noncommutativity. In this work, we gain further insight in the physical aspects of the spin noncommutativity. The noncommutative Dirac equation is derived from an action principle, and it is found to lead to the conservation of a modified current, which involves the background electromagnetic field. Finally, we study the Landau problem in the presence of spin noncommutativity. For this scenario of a constant magnetic field, we are able to derive a simple Hermitean non-commutative correction to the Hamiltonian operator, and show that the degeneracy of the excited states is lifted by the noncommutativity at the second order or perturbation theory.Comment: 18 pages, revtex

Serotyping Of Streptococcus Suis Strains Isolated From Pigs In The States Of São Paulo, Minas Gerais E Paraná, Brazil [sorotipagem De Amostras De Streptococcus Suis Isoladas De Suínos Em Granjas Dos Estados De Sã Paulo, Minas Gerais E Paraná]

Streptococcus suis infection in swine is common in all countries where hog production is well developed. This infection has been associated with bronchopneumonia, meningitis, arthritis, pericarditis, myocarditis, endocarditis, fibrinous polyserositis, septicaemia, rhinitis, and abortion. Streptococcus suis has also been described as a pathogen for ruminants and humans. In Brazil there are several clinical evidences about the existence of S. suis disease in pigs affecting more than 50% of farms in States of São Paulo, Minas Gerais and Paraná. In the present research 51 strains of S. suis isolated from piggeries of the States of São Paulo, Minas Gerais and Paraná were collected from different pathologies such as septicaemia, meningitis, arthritis and pneumonia and been recovered either in pure culture or as the predominant organism from porcine tissues. Culture of specimens was carried out on 5% bovine blood agar plates incubated at 37°C for 24 hr. For the biochemical identification the a-hemolytic colonies of all capsulated isolates were submitted to various conventional tests, such as hydrolysis of arginine, Voges-Proskauer Test, and production of acid from various carbohydrates (inulin, salicin, trehalose, lactose, sucrose, sorbitol, mannitol and glycerol). The strains were also tested for their ability to grow in the presence of 6,5% NaCl and for the amylase production. In addition strains were tested by Api Strep 20 to confirm the identification of S. suis. For capsular typing only capsulated strains were typed by co-agglutination test, using antisera raised in rabbits against all reference strains from serotypes 1 to 8. Strains belonging to other serotypes were also typed. The co-agglutination was used for serotyping and the capsular reaction test was carried out for measuring the potency of the prepared antisera. From the total of 51 examined strains the following results were obtained, with regard to serotyping: 30 (58,8%) were serotype 2, 11 (21,6%) were serotype 3, seven (13,72%) were serotype 7, two (3,92%) were serotype 1 and one strain belonged to serotype 14 (1,96%). As far as we are concerned, this is the first report on the isolation of a large number of S. suis strains in Brazil, from cases of illness caused by this bacterium among piglets. Also it was carried out serotyping of the isolates, showing a high prevalence of serotype 2, as compared to other known serotypes of S. suis.22115Arends, J.P., Zanen, H.C., Meningitis caused by Streptococcus suis in humans (1988) Rev. Infect. Dis., 10, pp. 131-137De Moor, C.E., (1963) Septicemic Infections in Pigs Caused by Haemolytic Streptococci of New Lancefield Groups Designated R, S and T. Antonie van Leeuvenhoek, 29, pp. 272-280Field, H.I., Buntain, D., Done, J.T., Studies on piglet mortality. I. Streptococcal meningitis and arthritis (1954) Vet. Rec., 66, pp. 453-455Galina, L., Collins, J.E., Pijoan, C., Porcine Streptococcus suis in Minnesota (1992) J. Vet. Diagn. Invest., 4, pp. 195-196Gottschalk, M., Segura, M., The pathogenesis of the meningitis caused by Streptococcus suis: The unresolved questions (2000) Vet. Microbiol., 76, pp. 259-272Gottschalk, M., Higgins, R., Jacques, M., Mittal, K.R., Henrichsen, J., Description of 14 new capsular types of Streptococcus suis (1989) J. Clin. Microbiol., 27, pp. 2633-2635Gottschalk, M., Higgins, R., Jacqnes, M., Beaudin, M., Henrichsen, J., Characterization of six new capsular types (23 through 28) of Streptococcus suis (1991) J. Clin. Microbiol., 29, pp. 2590-2594Higgins, R., Gottschalk, M., An update on Streptococcus suis identification (1990) J. Vet. Diagn. Invest., 2, pp. 249-252Higgins, R., Gottschalk, M., Distribution of Streptococcus suis capsular types in 1995 (1996) Can. Vet. J., 37, p. 242Higgins, R., Gottschalk, M., Boudreau, M., Lebrun, A., Henrichsen, J., Description of six new capsular types (29-34) of Streptococcus suis (1995) J. Vet. Invest., 7, pp. 405-406Hogg, A., Aamass, S.F., Hoffman, L.J., Wu, C.C., Clark, L.K., A survey of Streptococcus suis isolations by serotype and tissue of origin (1996) Proc. Am. Assoc. Swine Pract., pp. 79-81Hommez, J., Wullepit, J., Cassimon, P., Ceyssens, K., Devries, L.A., Streptococcus suis and other streptococcal species as a cause of extramammary infection in ruminants (1988) Vet. Rec., 123, pp. 626-627Jansen, E.J., Van Dorssen, C.A., Meningoencephalitis bij varkens door streptococcen (1951) Tijdschr. Diergeneeskd., 76, pp. 815-832Kataoka, Y., Sugimoto, C., Nakazawa, M., Morozumi, T., Kashiwazaki, M., The epidemiological studies of Streptococcus suis infections in Japan from 1987 to 1991 (1993) J. Vet. Med., 55, pp. 623-626Kilper-Balz, R., Schleifer, K.H., Streptococcus suis sp. nov.nom. rev. (1987) Int. J. Syst. Bacteriol., 37, pp. 160-162Mittal, K., Higgins, R., Larivière, S., Leblanc, D., A 2-mercaptoetanol tube agglutination test for diagnosis of Haemophilus pleuropneumoniae infection in pigs (1984) Am J. Vet. Res., 45, pp. 715-719Perch, B., Pedersen, K.B., Henrichse, J., Serology of capsulated streptococci pathogenic for pigs: Six new serotypes of Streptococcus suis (1983) J. Clin. Microbiol., 17, pp. 993-996Prieto, C., Garcia, F.J., Suarez, P., Imaz, M., Castro, J.M., Biochemical traits and antimicrobial susceptibility of Streptococcus suis isolated from slaughtered pigs (1994) J. Vet. Med. B, 41, pp. 608-617Reams, R.Y., Harrington, D.D., Glickman, L.T., Thacker, H.L., Bowersock, T.L., Multiple serotypes and strains of Streptococcus suis in naturally infected swine herds (1996) J. Vet. Diagn. Invest., 8, pp. 119-121Windsor, R.S., Elliot, S.D., Streptococcal infection in young pigs. IV. An outbreak of streptococcal meningitis in weaned pigs (1975) J. Hyg., 75, pp. 69-78Zanen, H.C., Engel, H.W.B., Porcine streptococci causing meningitis and septicaemia in man (1975) Lancet, 7919, pp. 1286-128