991 resultados para ddc:590
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Volumetric data at micrometer level resolution can be acquired within a few minutes using synchrotron-radiation-based tomographic microscopy. The field of view along the rotation axis of the sample can easily be increased by stacking several tomograms, allowing the investigation of long and thin objects at high resolution. On the contrary, an extension of the field of view in the perpendicular direction is non-trivial. This paper presents an acquisition protocol which increases the field of view of the tomographic dataset perpendicular to its rotation axis. The acquisition protocol can be tuned as a function of the reconstruction quality and scanning time. Since the scanning time is proportional to the radiation dose imparted to the sample, this method can be used to increase the field of view of tomographic microscopy instruments while optimizing the radiation dose for radiation-sensitive samples and keeping the quality of the tomographic dataset on the required level. This approach, dubbed wide-field synchrotron radiation tomographic microscopy, can increase the lateral field of view up to five times. The method has been successfully applied for the three-dimensional imaging of entire rat lung acini with a diameter of 4.1 mm at a voxel size of 1.48 microm.
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Iron-platinum nanoparticles embedded in a poly(methacrylic acid) (PMA) polymer shell and fluorescently labeled with the dye ATTO 590 (FePt-PMA-ATTO-2%) are investigated in terms of their intracellular localization in lung cells and potential to induce a proinflammatory response dependent on concentration and incubation time. A gold core coated with the same polymer shell (Au-PMA-ATTO-2%) is also included. Using laser scanning and electron microscopy techniques, it is shown that the FePt-PMA-ATTO-2% particles penetrate all three types of cell investigated but to a higher extent in macrophages and dendritic cells than epithelial cells. In both cell types of the defense system but not in epithelial cells, a particle-dose-dependent increase of the cytokine tumor necrosis factor alpha (TNFalpha) is found. By comparing the different nanoparticles and the mere polymer shell, it is shown that the cores combined with the shells are responsible for the induction of proinflammatory effects and not the shells alone. It is concluded that the uptake behavior and the proinflammatory response upon particle exposure are dependent on the time, cell type, and cell culture.
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Background In the 19th century, eminent French sociologist Emile Durkheim found suicide rates to be higher in the Protestant compared with the Catholic cantons of Switzerland. We examined religious affiliation and suicide in modern Switzerland, where assisted suicide is legal. Methods The 2000 census records of 1 722 456 (46.0%) Catholics, 1 565 452 (41.8%) Protestants and 454 397 (12.2%) individuals with no affiliation were linked to mortality records up to December 2005. The association between religious affiliation and suicide, with the Protestant faith serving as the reference category, was examined in Cox regression models. Hazard ratios (HRs) with 95% confidence intervals (CIs) were adjusted for age, marital status, education, type of household, language and degree of urbanization. Results Suicide rates per 100 000 inhabitants were 19.7 in Catholics (1664 suicides), 28.5 in Protestants (2158 suicides) and 39.0 in those with no affiliation (882 suicides). Associations with religion were modified by age and gender (P < 0.0001). Compared with Protestant men aged 35–64 years, HRs (95% CI) for all suicides were 0.80 (0.73–0.88) in Catholic men and 1.09 (0.98–1.22) in men with no affiliation; and 0.60 (0.53–0.67) and 1.96 (1.69–2.27), respectively, in men aged 65–94 years. Corresponding HRs in women aged 35–64 years were 0.90 (0.80–1.03) and 1.46 (1.25–1.72); and 0.67 (0.59–0.77) and 2.63 (2.22–3.12) in women aged 65–94 years. The association was strongest for suicides by poisoning in the 65–94-year-old age group, the majority of which was assisted: HRs were 0.45 (0.35–0.59) for Catholic men and 3.01 (2.37–3.82) for men with no affiliation; 0.44 (0.36–0.55) for Catholic women and 3.14 (2.51–3.94) for women with no affiliation. Conclusions In Switzerland, the protective effect of a religious affiliation appears to be stronger in Catholics than in Protestants, stronger in older than in younger people, stronger in women than in men, and particularly strong for assisted suicides.
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Three novel glycine-rich peptides, named ctenidin 1-3, with activity against the Gram-negative bacterium E. coli, were isolated and characterized from hemocytes of the spider Cupiennius salei. Ctenidins have a high glycine content (>70%), similarly to other glycine-rich peptides, the acanthoscurrins, from another spider, Acanthoscurria gomesiana. A combination of mass spectrometry, Edman degradation, and cDNA cloning revealed the presence of three isoforms of ctenidin, at least two of them originating from simple, intronless genes. The full-length sequences of the ctenidins consist of a 19 amino acid residues signal peptide followed by the mature peptides of 109, 119, or 120 amino acid residues. The mature peptides are post-translationally modified by the cleavage of one or two C-terminal cationic amino acid residue(s) and amidation of the newly created mature C-terminus. Tissue expression analysis revealed that ctenidins are constitutively expressed in hemocytes and to a small extent also in the subesophageal nerve mass.
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Defensins are a major family of antimicrobial peptides found throughout the phylogenetic tree. From the spider species: Cupiennius salei, Phoneutria reidyi, Polybetes pythagoricus, Tegenaria atrica, and Meta menardi, defensins belonging to the 'ancestral' class of invertebrate defensins were cloned and sequenced. The deduced amino acid sequences contain the characteristic six cysteines of this class of defensins and reveal precursors of 60 or 61 amino acid residues. The mature peptides consist of 37 amino acid residues, showing up to 70% identities with tick and scorpion defensins. In C. salei, defensin mRNA was found to be constitutively expressed in hemocytes, ovaries, subesophageal nerve mass, hepatopancreas, and muscle tissue. This is the first report presenting and comparing antimicrobial peptides belonging to the family of defensins from spiders.
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Objectives: To evaluate the extent of bone fill over 3 years following the surgical treatment of peri-implantitis with bone grafting with or without a membrane. Material and Methods: In a non-submerged wound-healing mode, 15 subjects with 27 implants were treated with a bone substitute (Algipore®) alone and 17 subjects with 29 implants were treated with the bone substitute and a resorbable membrane (Osseoquest®). Implants with radiographic bone loss ≥1.8 mm following the first year in function and with bleeding and/or pus on probing were included. Following surgery, subjects were given systemic antibiotics (10 days) and rinsed with chlorhexidine. After initial healing, the subjects were enrolled in a strict maintenance programme. Results: Statistical analysis failed to demonstrate changes in bone fill between 1 and 3 years both between and within procedure groups. The mean defect fill at 3 years was 1.3 ± (SD) 1.3 mm if treated with the bone substitute alone and 1.6 ± (SD) 1.2 mm if treated with an adjunct resorbable membrane, (p=0.40). The plaque index decreased from approximately 40–10%, remaining stable during the following 2 years. Conclusion: Defect fill using a bone substitute with or without a membrane technique in the treatment of peri-implantitis can be maintained over 3 years.
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This article retraces the “genealogy” of the fideist perspective in philosophy as well as literature, especially within the writings of Søren Kierkegaard and the novel Don Quixote. It contends that a demythologized perspective of the fideist-humanist sort, based upon Erasmian tolerance and intellectual creativity and updated with the insights of post-analytic theory (e.g., the work of Alasdair MacIntyre, Richard Rorty, and Jeffrey Stout), without revoking the vocabulary of transcendence, can reinforce the weathered but still valuable post-Enlightenment moral vocabulary, and can reiterate the humaneness of liberal hope without undue encumbrance from the dogmatic baggage of traditional theological jargon and metaphysics.
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Cupiennius salei single insulin-like growth factor-binding domain protein (SIBD-1), which exhibits an IGFBP N-terminal domain-like profile, was identified in the hemocytes of the spider C. salei. SIBD-1 was purified by RP-HPLC and the sequence determined by a combination of Edman degradation and 5'-3'- RACE PCR. The peptide (8676.08 Da) is composed of 78 amino acids, contains six intrachain disulphide bridges and carries a modified Thr residue at position 2. SIBD-1 mRNA expression was detected by quantitative real-time PCR mainly in hemocytes, but also in the subesophageal nerve mass and muscle. After infection, the SIBD-1 content in the hemocytes decreases and, simultaneously, the temporal SIBD-1 expression seems to be down-regulated. Two further peptides, SIBD-2 and IGFBP-rP1, also exhibiting IGFBP N-terminal domain variants with unknown functions, were identified on cDNA level in spider hemocytes and venom glands. We conclude that SIBD-1 may play an important role in the immune system of spiders.
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This review on all spider venom components known by the end of 2010 bases on 1618 records for venom compounds from 174 spider species (= 0.41% of all known species) belonging to 32 families (= 29% of all existing spider families). Spiders investigated for venom research are either big (many mygalomorph species, Nephilidae, Ctenidae and Sparassidae) or medically important for humans (e.g. Loxosceles or Latrodectus species). Venom research widely ignored so far the two most species-rich families (Salticidae and Linyphiidae) and strongly neglected several other very abundant families (Araneidae, Lycosidae, Theridiidae, Thomisidae and Gnaphosidae). We grouped the known 1618 records for venom compounds into six categories: low molecular mass compounds (16 % of all compounds), acylpolyamines (11 %), linear peptides (6 %), cysteine-knotted mini-proteins (60 %), neurotoxic proteins (1 %) and enzymes (6 %). Low molecular mass compounds are known from many spider families and contain organic acids, nucleosides, nucleotides, amino acids, amines, polyamines, and some further substances, many of them acting as neurotransmitters. Acylpolyamines contain amino acids (Araneidae and Nephilidae) or not (several other families) and show a very high diversity within one species. Linear peptides, also called cytolytic, membranolytic or antimicrobial, exert a highly specific structure and are so far only known from Ctenidae, Lycosidae, Oxyopidae and Zodariidae. Cysteine-knotted mini-proteins represent the majority of venom compounds because research so far focused on them. They probably occur in most but not all spider families. Neurotoxic proteins so far are only known from theridiid spiders. Enzymes had been neglected for some time but meanwhile it becomes obvious that they play an important role in spider venoms. Sixteen enzymes either cleave polymers in the extracellular matrix or target phospholipids and related compounds in membranes. The overall structure of these compounds is given and the function, as far as it is known, is described. Since several of these component groups are presented in one average spider venom, we discuss the known interactions and synergisms and give reasons for such a functional redundancy. We also discuss main evolutionary pathways for spider venom compounds such as high variability among components of one group, synergistic interactions between cysteine-knotted mini-proteins and other components (low molecular mass compounds and linear peptides), change of function from ion-channel acting mini-proteins to cytolytic effects and replacement of mini-proteins by linear peptides, acylpolyamines, large proteins or enzymes. We also add first phylogenetic considerations.
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Cupiennin 1a, a cytolytic peptide isolated from the venom of the spider Cupiennius salei, exhibits broad membranolytic activity towards bacteria, trypanosomes, and plasmodia, as well as human blood and cancer cells. In analysing the cytolytic activity of synthesised all-d- and all-l-cupiennin 1a towards pro- and eukaryotic cells, a stereospecific mode of membrane destruction could be excluded. The importance of negatively charged sialic acids on the outer leaflet of erythrocytes for the binding and haemolytic activity of l-cupiennin 1a was demonstrated. Reducing the overall negative charges of erythrocytes by partially removing their sialic acids or by protecting them with tri- or pentalysine results in reduced haemolytic activity of the peptide.
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Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.step-project.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales.
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Aim. The quantitative genetics underlying correlated behavioural traits (‘‘animal personality’’) have hitherto been studied mainly in domesticated animals. Here we report the repeatability ( ) and heritability ( ) of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the of behavioural types by variance components estimation (GLMM REML), using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546), but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All estimates were significant but low (e.g., pair identity SE). Additionally, we found significant variation between broods nested within the parent(s), but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable , in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (non)genetic effects.