955 resultados para Components of the surface
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Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current “omics” era and the available data are mostly scattered or in “tables” that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.
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The contributions of the correlated and uncorrelated components of the electron-pair density to atomic and molecular intracule I(r) and extracule E(R) densities and its Laplacian functions ∇2I(r) and ∇2E(R) are analyzed at the Hartree-Fock (HF) and configuration interaction (CI) levels of theory. The topologies of the uncorrelated components of these functions can be rationalized in terms of the corresponding one-electron densities. In contrast, by analyzing the correlated components of I(r) and E(R), namely, IC(r) and EC(R), the effect of electron Fermi and Coulomb correlation can be assessed at the HF and CI levels of theory. Moreover, the contribution of Coulomb correlation can be isolated by means of difference maps between IC(r) and EC(R) distributions calculated at the two levels of theory. As application examples, the He, Ne, and Ar atomic series, the C2-2, N2, O2+2 molecular series, and the C2H4 molecule have been investigated. For these atoms and molecules, it is found that Fermi correlation accounts for the main characteristics of IC(r) and EC(R), with Coulomb correlation increasing slightly the locality of these functions at the CI level of theory. Furthermore, IC(r), EC(R), and the associated Laplacian functions, reveal the short-ranged nature and high isotropy of Fermi and Coulomb correlation in atoms and molecules
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PURPOSE: To identify the genetic defect for the Coppock-like cataract (CCL) affecting a Swiss family, which defect was unlinked to the chromosome 2q33-35 CCL locus. METHODS: A large family was characterized for linkage analysis by slit lamp examination or by the review of drawings made before cataract extraction. The affection status was attributed before genotyping, and the genotyping was masked to the affection status. Two-point and multipoint linkage analyses were performed using the MLINK and the LINKMAP components of the LINKAGE program package (ver. 5.1), respectively. Mutational analysis of candidate genes was performed by a combination of direct cycle sequencing and an amplification refractory mutation system assay. RESULTS: Ten individuals were affected with the CCL phenotype. The disease was autosomal dominant and appeared to be fully penetrant. A new CCL locus was identified on chromosome 22q11.2 within a 11.67-cM interval (maximum lod score [Zmax] = 4.14; theta = 0). Mutational analysis of the CRYBB2 candidate gene identified a disease-causing mutation in exon 6. This sequence change was identical with that previously described to be associated with the cerulean cataract, a clinically distinct entity. CONCLUSIONS: The CCL phenotype is genetically heterogeneous with a second gene on chromosome 22q11.2, CRYBB2. The CCL and the cerulean cataract are two distinct clinical entities associated with the same genetic defect. This work provides evidence for a modifier factor that influences cataract formation and that remains to be identified.
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Summary The NACHT, LRR and PYD domains containing protein (NALP3) inflammasome is a key regulator of interleukin-1beta (IL-1beta) secretion. As there is strong evidence for a pro-inflammatory role of IL-1beta in rheumatoid arthritis (RA) and in murine models of arthritis, we explored the expression of the different components of the NALP3 inflammasome as well as other nucleotide oligomerization domain (NOD)-like receptors (NLRs) in synovium obtained from patients with RA. The expression of NLRs was also studied in fibroblast lines derived from joint tissue. By immunohistology, NALP3 and apoptosis-associated speck-like protein containing a CARD domain (ASC) were expressed in myeloid and endothelial cells and B cells. T cells expressed ASC but lacked NALP3. In synovial fibroblast lines, NALP3 expression was not detected at the RNA and protein levels and stimulation with known NALP3 agonists failed to induce IL-1beta secretion. Interestingly, we were unable to distinguish RA from osteoarthritis synovial samples on the basis of their basal level of RNA expression of known NLR proteins, though RA samples contained higher levels of caspase-1 assayed by enzyme-linked immunsorbent assay. These results indicate that myeloid and endothelial cells are the principal sources of inflammasome-mediated IL-1beta production in the synovium, and that synovial fibroblasts are unable to activate caspase-1 because they lack NALP3. The NALP3 inflammasome activity does not account for the difference in level of inflammation between RA and osteoarthritis.
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The phosphatidylinositol 3-kinase-mammalian target of rapamycin (PI3K-mTOR) pathway plays pivotal roles in cell survival, growth, and proliferation downstream of growth factors. Its perturbations are associated with cancer progression, type 2 diabetes, and neurological disorders. To better understand the mechanisms of action and regulation of this pathway, we initiated a large scale yeast two-hybrid screen for 33 components of the PI3K-mTOR pathway. Identification of 67 new interactions was followed by validation by co-affinity purification and exhaustive literature curation of existing information. We provide a nearly complete, functionally annotated interactome of 802 interactions for the PI3K-mTOR pathway. Our screen revealed a predominant place for glycogen synthase kinase-3 (GSK3) A and B and the AMP-activated protein kinase. In particular, we identified the deformed epidermal autoregulatory factor-1 (DEAF1) transcription factor as an interactor and in vitro substrate of GSK3A and GSK3B. Moreover, GSK3 inhibitors increased DEAF1 transcriptional activity on the 5-HT1A serotonin receptor promoter. We propose that DEAF1 may represent a therapeutic target of lithium and other GSK3 inhibitors used in bipolar disease and depression.
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In the latest years the importance of high resolution analysis of the microbial cell surface has been increasingly recognized. Indeed, in order to better understand bacterial physiology and achieve rapid diagnostic and treatment techniques, a thorough investigation of the surface modifications induced on bacteria by different environmental conditions or drugs is essential. Several instruments are nowadays available to observe at high resolution specific properties of microscopic samples. Among these, AFM can routinely study single cells in physiological conditions, measuring the mechanical properties of their membrane at a nanometric scale (force volume). Such analyses, coupled with high resolution investigation of their morphological properties, are increasingly used to characterize the state of single cells. In this work we exploit such technique to characterize bacterial systems. We have performed an analysis of the mechanical properties of bacteria (Escherichia coli) exposed to different conditions. Such measurements were performed on living bacteria, by changing in real-time the liquid environment: standard phosphate buffered saline, antibiotic (ampicillin) in PBS and growth medium. In particular we have focused on the determination of the membrane stiffness modifications induced by these solutions, in particular between stationary and replicating phases and what is the effect of the antibiotic on the bacterial structure.
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Monte Carlo simulations of a model for gamma-Fe2O3 (maghemite) single particle of spherical shape are presented aiming at the elucidation of the specific role played by the finite size and the surface on the anomalous magnetic behavior observed in small particle systems at low temperature. The influence of the finite-size effects on the equilibrium properties of extensive magnitudes, field coolings, and hysteresis loops is studied and compared to the results for periodic boundaries. It is shown that for the smallest sizes the thermal demagnetization of the surface completely dominates the magnetization while the behavior of the core is similar to that of the periodic boundary case, independently of D. The change in shape of the hysteresis loops with D demonstrates that the reversal mode is strongly influenced by the presence of broken links and disorder at the surface
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An experimental modification of the transverse groove surface texture of a section of an urban interstate highway was performed by the Iowa Department of Transportation. Transverse groove texturing i s a design feature required by the Federal Highway Administration t o reduce skidding under wet pavement conditions. Adjacent residents claimed the texturing was the cause of especially annoying tonal characteristics within the traffic noise. A research proposal to modify the existing texture pattern by surface grinding and to study the noise and friction effects was approved for funding by the Iowa Highway Research Board. Results i n the form of a comparison between traffic noise before modification and traffic noise immediately after and 15 months after modification indicate that the change in surface texture has lowered overall traffic noise levels by reducing a high frequency component of the traffic noise spectrum. Fraffic testing data show reduced capacity of the roadway to inhibit wet pavement skidding as a result of the surface modification.
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The COP9 signalosome (CSN) is an evolutionarily conserved macromolecular complex that interacts with cullin-RING E3 ligases (CRLs) and regulates their activity by hydrolyzing cullin-Nedd8 conjugates. The CSN sequesters inactive CRL4(Ddb2), which rapidly dissociates from the CSN upon DNA damage. Here we systematically define the protein interaction network of the mammalian CSN through mass spectrometric interrogation of the CSN subunits Csn1, Csn3, Csn4, Csn5, Csn6 and Csn7a. Notably, we identified a subset of CRL complexes that stably interact with the CSN and thus might similarly be activated by dissociation from the CSN in response to specific cues. In addition, we detected several new proteins in the CRL-CSN interactome, including Dda1, which we characterized as a chromatin-associated core subunit of multiple CRL4 proteins. Cells depleted of Dda1 spontaneously accumulated double-stranded DNA breaks in a similar way to Cul4A-, Cul4B- or Wdr23-depleted cells, indicating that Dda1 interacts physically and functionally with CRL4 complexes. This analysis identifies new components of the CRL family of E3 ligases and elaborates new connections between the CRL and CSN complexes.
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The energy budgets of two freshwater gastropds, Lymnae peregra and Physa acuta, were compared in similar experimental conditions (20ºC, fed ad libitum with 24h-decayed lettuce), and found to differ in several ways. 1) L. Peregra has a higher assimilation efficiency than P. acuta (72% vs 60%). 2) These species assimilate different components of the ingested food: P. acuta uses a smaller, but more energetic part (probably mainly bacteria), whereas L. peregra assimilate a larger, but less energetic part (probably mainly cellulose). 3) L. peregra allocates more of its assimilated energy to oxygene consumption and mucus production (maintenance investments), wheras P. acuta invest more in growth and reproduction (production investments). Such differences are relevant to the natural habitat of these two species: P. acuta colonizes warm, eutrophic and temporary pools, where decaying material constitue the main part of available resources, and where adult mortality is high and impredictible. By contrast, L. peregra is frequently found in colder, oligotrophic and predictible environements, where living primary producers constitute the main part of available resources, and where biotic interactions are important factors of mortality.
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Purpose: Adiponectin, arterial stiffness, as well components of the renin-angiotensin system are associated with cardiovascular risk. This study was aimed to investigate whether plasma adiponectin was directly linked with pulse pressure (PP), as a marker for arterial stiffness, and the renin-angiotensin system (RAS). Methods and materials: A family-based study in subjects of African descent enriched with hypertensive patients was carried out in the Seychelles. Fasting plasma adiponectin was determined by ELISA, plasma renin activity according to the antibody-trapping principle and plasma aldosterone by radioimmunoassay. Daytime ambulatory blood pressure (BP) was measured using Diasys Integra devices. PP was calculated as the difference between systolic and diastolic BP. The association of adiponectin with PP, plasma renin activity and plasma aldosterone were analyzed using generalized estimating equations with a gaussian family link and an exchangeable correlation structure to account for familial aggregation. Results: Data from 335 subjects from 73 families (152 men, 183 women) were available. Men and women had mean (SD) age of 45.4 ± 11.1 and 47.3 ± 12.4 years, BMI of 26.3 ± 4.4 and 27.8 ± 5.1 kg/m2, daytime systolic/diastolic BP of 132.6 ± 15.4 / 86.1 ± 10.9 and 130 ± 17.6 / 83.4 ± 11.1 mmHg, and daytime PP of 46.5 ± 9.9 and 46.7 ± 10.7 mmHg, respectively. Plasma adiponectin was 4.4± 3.04 ng/ml in men and 7.39 ± 5.44 ng/ml in women (P <0.001). After adjustment for age, sex and BMI, log-transformed adiponectin was negatively associated with daytime PP (-0.009 ± 0.003, P = 0.004), plasma renin activity (-0.248 ± 0.080, P = 0.002) and plasma aldosterone (-0.004 ± 0.002, P = 0.014). Conclusion: Low adiponectin is associated with increased ambulatory PP and RAS activation in subjects of African descent. Our data are consistent with the observation that angiotensin II receptor blockers increase adiponectin in humans.
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Objecte: L'aplicació de la NIC 32 en les cooperatives ha generat una important controvèrsia en els últims anys. Fins al moment, s'han realitzat diversos treballs que intenten preveure els possibles efectes de la seva aplicació. Aquest treball pretén analitzar l'impacte de la primera aplicació de la NIC 32 en el sector cooperatiu. Disseny/metodologia/enfocament: S'ha seleccionat una mostra de 98 cooperatives, i s'ha realitzat una anàlisi comparativa de la seva informació financera presentada abans i després de l'aplicació de la NIC 32, per a determinar les diferències existents. S’ha utilitzat la prova de la suma de rangs de Wilcoxon per comprovar si aquestes diferències són significatives. També s’ha utilitzat la prova de la U de Mann Whitney per comprovar si existeixen diferències significatives en l’impacte relatiu de l’aplicació de la NIC 32 entre diversos grups de cooperatives. Finalment, s'ha realitzat una anàlisi dels efectes de l'aplicació de la NIC 32 en la situació patrimonial i econòmica de les cooperatives, i en l'evolució dels seus actius intangibles, mitjançant l’ús de tècniques d’anàlisi econòmico-financera. Aportacions i resultats: Els resultats obtinguts confirmen que l'aplicació de la NIC 32 provoca diferències significatives en algunes partides del balanç de situació i el compte de pèrdues i guanys, així com en les ràtios analitzades. Les principals diferències es concreten en una reducció del nivell de capitalització i un augment de l'endeutament de les cooperatives, així com un empitjorament general dels ràtios de solvència i autonomia financera. Limitacions: Cal tenir en compte que el treball s'ha realitzat amb una mostra de cooperatives que estan obligades a auditar els seus comptes anuals. Per tant, els resultats obtinguts han d'interpretar-se en un context de cooperatives de tamany elevat. També cal tenir en compte que hem realitzat una anàlisi comparativa dels comptes anuals de 2011 i 2010. Això ens ha permès conèixer les diferències en la informació financera de les cooperatives abans i després d'aplicar la NIC 32. Encara que algunes d’aquestes diferències també podrien estar causades per altres factors com la situació econòmica, els canvis en l'aplicació de les normes comptables, etc. Originalitat/valor afegit: Creiem que és el moment idoni per a realitzar aquest treball d'investigació, ja que des de 2011 totes les cooperatives espanyoles han d'aplicar les normes comptables adaptades a la NIC 32. A més, fins on coneixem, no existeixen altres treballs similars realitzats amb comptes anuals de cooperatives que ja han aplicat les normes comptables adaptades a la NIC 32 . Creiem que els resultats d'aquest treball d'investigació poden ser útils per a diferents grups d'interès. En primer lloc, perquè els organismes emissors de normes comptables puguin conèixer l'abast de la NIC 32 en les cooperatives i, puguin plantejar millores en el contingut de la norma. En segon lloc, perquè les pròpies cooperatives, federacions, confederacions i altres organismes cooperatius disposin d'informació sobre l'impacte econòmic de la primera aplicació de la NIC 32, i puguin realitzar les valoracions que creguin convenients. I en tercer lloc, perquè les entitats financeres, auditors i assessors de cooperatives i altres grups d'interès disposin d'informació sobre els canvis en els comptes anuals de les cooperatives, i puguin tenir-los en compte a l'hora de prendre decisions. Paraules clau: Cooperatives, patrimoni net, capital social, NIC 32, solvència, efectes de la normativa comptable, informació financera, ràtios.
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1. Wood ants (Formica paralugubris) incorporate large amounts of solidified conifer resin into their nest, which reduces the density of many bacteria and fungi and protects the ants against some detrimental micro-organisms. By inducing an environment unfavourable to pathogens, the presence of resin may allow workers to reduce the use of their immune system. 2. The present study tested the hypothesis that the presence of resin decreases the immune activity of wood ants. Specifically, three components of the humoral immune defences of workers kept in resin-rich and resin-free experimental nests (antibacterial, lytic, and prophenoloxidase activities) were compared. 3. The presence of resin was associated with reduced bacterial and fungal densities in nest material and with a small decrease in worker antibacterial and lytic activities. The prophenoloxidase activity was very low in all workers and was not affected by the presence of resin. 4. These results suggest that collective medication with resin reduces pathogen pressure, which in turn decreases the use of the inducible part of the immune system. More generally, the use of plant secondary compounds might be an efficient and economical way to fight pathogens.
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Lassa virus (LASV) causing hemorrhagic Lassa fever in West Africa, Mopeia virus (MOPV) from East Africa, and lymphocytic choriomeningitis virus (LCMV) are the main representatives of the Old World arenaviruses. Little is known about how the components of the arenavirus replication machinery, i.e., the genome, nucleoprotein (NP), and L protein, interact. In addition, it is unknown whether these components can function across species boundaries. We established minireplicon systems for MOPV and LCMV in analogy to the existing LASV system and exchanged the components among the three systems. The functional and physical integrity of the resulting complexes was tested by reporter gene assay, Northern blotting, and coimmunoprecipitation studies. The minigenomes, NPs, and L proteins of LASV and MOPV could be exchanged without loss of function. LASV and MOPV L protein was also active in conjunction with LCMV NP, while the LCMV L protein required homologous NP for activity. Analysis of LASV/LCMV NP chimeras identified a single LCMV-specific NP residue (Ile-53) and the C terminus of NP (residues 340 to 558) as being essential for LCMV L protein function. The defect of LASV and MOPV NP in supporting transcriptional activity of LCMV L protein was not caused by a defect in physical NP-L protein interaction. In conclusion, components of the replication complex of Old World arenaviruses have the potential to functionally and physically interact across species boundaries. Residue 53 and the C-terminal domain of NP are important for function of L protein during genome replication and transcription.
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The seven members of the FXYD protein family associate with the Na(+)-K(+) pump and modulate its activity. We investigated whether conserved cysteines in FXYD proteins are susceptible to glutathionylation and whether such reactivity affects Na(+)-K(+) pump function in cardiac myocytes and Xenopus oocytes. Glutathionylation was detected by immunoblotting streptavidin precipitate from biotin-GSH loaded cells or by a GSH antibody. Incubation of myocytes with recombinant FXYD proteins resulted in competitive displacement of native FXYD1. Myocyte and Xenopus oocyte pump currents were measured with whole-cell and two-electrode voltage clamp techniques, respectively. Native FXYD1 in myocytes and FXYD1 expressed in oocytes were susceptible to glutathionylation. Mutagenesis identified the specific cysteine in the cytoplasmic terminal that was reactive. Its reactivity was dependent on flanking basic amino acids. We have reported that Na(+)-K(+) pump β(1) subunit glutathionylation induced by oxidative signals causes pump inhibition in a previous study. In the present study, we found that β(1) subunit glutathionylation and pump inhibition could be reversed by exposing myocytes to exogenous wild-type FXYD3. A cysteine-free FXYD3 derivative had no effect. Similar results were obtained with wild-type and mutant FXYD proteins expressed in oocytes. Glutathionylation of the β(1) subunit was increased in myocardium from FXYD1(-/-) mice. In conclusion, there is a dependence of Na(+)-K(+) pump regulation on reactivity of two specifically identified cysteines on separate components of the multimeric Na(+)-K(+) pump complex. By facilitating deglutathionylation of the β(1) subunit, FXYD proteins reverse oxidative inhibition of the Na(+)-K(+) pump and play a dynamic role in its regulation.