1,721,550 research outputs found
Morfologia del Saliente di Is Morus – Pula (CA) e idrodinamica attorno allo scoglio antistante
No full textSubmerged structures are becoming increasingly popular due to their capacity of providing necessary beach protection
without negative aesthetic impacts. Although large literature is available, the shoreline response to submerged
structures is not well understood at the present. Results show that these structures may induce shoreline erosion as
well as shoreline accretion. This paper aims to present the results of numerical physical modeling tests applied to
the Is Morus beach (Sardinia) where a natural submerged reef has created a widening of the beach in the form of
salient. Results are in accordance with empirical relationships provided by literature for predicting salient shape
and geometrical properties
beta-Barrel membrane bacterial proteins: structure, function, assembly and interaction with lipids
No full textFifteen-year mortality of patients with asthma-COPD overlap syndrome
No full textBackground: The coexistence of asthma and chronic obstructive pulmonary disease (asthma-COPD overlap syndrome: ACOS) is increasingly recognized but data about its prevalence and long-term mortality are needed. Methods: Prevalence of ACOS and 15-year mortality rates were assessed in 1065 subjects aged>. 65. years, enrolled in the SA.R.A. study, with complete clinical, lung functional and follow-up data. Physical performance, disease-related disability, and health-related quality of life (HRQL) were also evaluated. Results: ACOS was found in 11.1% of subjects (29.4% of those previously diagnosed with COPD and 19.7% of those with asthma). ACOS was positively associated with impaired physical performance, functional ability, and HRQL. Individuals with ACOS had higher mortality rates than controls (7.17 per 100 person-years; mortality rate ratio: 1.83). After adjustment for the main confounders, the risk of all-cause mortality remained significantly increased in subjects with ACOS (HR: 1.82), COPD (HR: 2.12), and restriction (HR: 2.41), but not asthma. Conclusions: Long-term prognosis of ACOS was similar to COPD, and worse than asthma and healthy controls. ACOS had a significant impact on physical performance, functional ability, and HRQL
Structure, dynamics, and stability of assemblies of the human prion fragment SNQNNF
No full textMisfolding of the prion protein (PrP) is associated with the development of Transmissible Spongiform Encephalopathies. The recent crystal structure of 'steric zipper' aggregates of the peptide SNQNNF (human PrP fragment 170-175) has highlighted its potential involvement in the misfolding process. A detailed molecular dynamics investigation on SNQNNF aggregates has been performed to analyze the behavior of the assemblies in a non-crystalline context. Stability, dynamics, and structural features suggest that SNQNNF assemblies are very good candidates to be involved in the structure of PrP fibrils. In addition, the analysis of small aggregates shows that steric zipper interfaces are able to stabilize assemblies composed of four strands per sheet. Altogether, the present findings indicate that steric zipper may play a key role in prion diseases. This suggestion is also corroborated by MD analyses of point mutations within the region 170-175. © 2007 Elsevier Inc. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Conformational features of peptidic nucleic acids for the rational design of biologically active PNAs and hybrids PNA-oligonucleotides
No full textThe search for new oligonucleotides with improved properties represents an important step for the development of oligonucleotides as powerful biomolecular tools, antisense and antigene agents, molecular probes and biosensors. One of the most interesting of the new derivatives is Peptide Nucleic Acid (PNA), an analogue of DNA in which the backbone is a pseudopeptide rather than a sugar. PNA mimics the behaviour of DNA and binds complementary nucleic acid strands, with higher affinity and specificity than corresponding oligonucleotides. The unique properties of PNA open up novel molecular biology and biochemistry applications that are unachievable with traditional oligonucleotides and peptides. The non-charged nature of the PNA backbone is an important feature leading to higher thermal stability of PNA/DNA duplexes compared to DNA/DNA duplexes and stability of PNA duplexes with DNA independent of salt concentration. PNA oligomers are resistant to degradation by enzymes, and the lifetime of these compounds is extended both in vivo and in vitro. The direction of rational drug design of new PNA with specific functions depends critically on understanding the basic principles of specificity of biomolecular recognition for this class of molecules. Thus, the comparative analysis of conformational data on PNA/PNA, PNA/RNA, PNA/DNA duplexes and PNA2/DNA triplex represents the starting point for the design of new PNAs. In addition, the investigation of modified PNAs and PNA/DNA chimeras may provide a new generation of nucleic acid mimetics with large-scale application in biological systems
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