292 research outputs found
Analyses of damaged effects on jacket type offshore platform
U ovom je istraživanju izvanobalna platforma, koja je podvrgnuta dinamičkom opterećenju za različite slučajeve oštećenja, modelirana analizom interakcije fluida i konstrukcije (engl. fluid-structure interaction - FSI). Razmatrani su različiti modeli oštećenja u slučaju kada je jedan stup bio oštećen, a Youngov modul oštećenog elementa smanjen je s četiri različita omjera intenziteta. Osim pet oštećenih konstrukcija, neoštećena je konstrukcija modelirana prema dva različita uvjeta razmaka stupova. Na taj su način oštećeni modeli uspoređivani i međusobno i s neoštećenim modelima. U ovom su radu modeli ispitivani primjenom numeričkog FSI postupka. Numerički postupak potvrđen je poluanalitičkim modeliranjem. U ovoj je fazi jednadžba gibanja jednog od konstrukcijskih modela riješena poluanalitičkom metodom temeljenom na sustavu s više stupnjeva slobode. Osim toga, numerički model okoline potvrđen je primjenom poluanalitičkog rješenja jednadžbe gibanja slobodne površine i krivulje valna brzina-valna sila. Za modeliranje konstrukcija i njihove okoline upotrijebljen je program Abaqus, utemeljen na metodi konačnih elemenata. Konstrukcije su modelirane primjenom Lagrangeova postupka, fluidno okruženje je modelirano primjenom Eulerova postupka. Modelirani su i uvjeti razmaka stupova i različiti omjeri intenziteta, te je zabilježen najnegativniji tip oštećenja.In this paper, an offshore platform subjected to dynamic loading for different damage cases was modelled via fluid-structure interaction (FSI) analysis. Different damage models were considered in the case where one leg was broken, and the Young’s modulus of the damaged member was reduced with four different severity ratios. In addition to the five damaged structures, the undamaged structure was modelled according to two different leg spacing conditions. Thus, the damaged models were compared among themselves as well as with undamaged models. In this study, models were investigated using a numerical FSI technique. The numerical technique was verified using semi-analytical modelling. At this stage, the equation of motion of one of the structural models was solved using a semi-analytical method based on a multi-degree-of-freedom system. In addition, the numerical environment model was verified using a semi-analytical solution of the free-surface motion equation and the wave velocity-wave force curve. An Abaqus finite-element analysis program was used to model the structures and their surroundings. While the structures were modelled using the Lagrangian technique, the fluid surroundings were modelled using the Eulerian technique. Both the conditions of leg spacing and different severity ratios were modelled, and the most negative damage type was revealed
Transmutations and spectral parameter power series in eigenvalue problems
We give an overview of recent developments in Sturm-Liouville theory
concerning operators of transmutation (transformation) and spectral parameter
power series (SPPS). The possibility to write down the dispersion
(characteristic) equations corresponding to a variety of spectral problems
related to Sturm-Liouville equations in an analytic form is an attractive
feature of the SPPS method. It is based on a computation of certain systems of
recursive integrals. Considered as families of functions these systems are
complete in the -space and result to be the images of the nonnegative
integer powers of the independent variable under the action of a corresponding
transmutation operator. This recently revealed property of the Delsarte
transmutations opens the way to apply the transmutation operator even when its
integral kernel is unknown and gives the possibility to obtain further
interesting properties concerning the Darboux transformed Schr\"{o}dinger
operators.
We introduce the systems of recursive integrals and the SPPS approach,
explain some of its applications to spectral problems with numerical
illustrations, give the definition and basic properties of transmutation
operators, introduce a parametrized family of transmutation operators, study
their mapping properties and construct the transmutation operators for Darboux
transformed Schr\"{o}dinger operators.Comment: 30 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1111.444
Elevated levels of protein AMBP in cerebrospinal fluid of women with preeclampsia compared to normotensive pregnant women
Purpose: To investigate the cerebrospinal fluid (CSF) proteome of patients with preeclampsia (PE) and normotensive pregnant women, in order to provide a better understanding of brain involvement in PE. Experimental design: Ninety-eight CSF samples (43 women with PE and 55 normotensive controls) were analyzed by LC-MS/MS proteome profiling. CSF was obtained during the spinal puncture before caesarean delivery. Results: Eight proteins were higher abundant and 17 proteins were lower abundant in patients with PE. The most significantly differentially abundant protein was protein AMBP (alpha-1-microglobulin/bikunin precursor). This finding was validated by performing an ELISA experiment (p = 0.002). Conclusions and clinical relevance: The current study showed a clear difference between the protein profiles of CSF from patients with PE and normotensive pregnant women. Protein AMBP is a precursor of a heme-binding protein that counteracts the damaging effects of free hemoglobin, which may be related to the presence of free hemoglobin in CSF. Protein levels showed correlations with clinical symptoms during pregnancy and postpartum. To our knowledge, this is the first LC-MS/MS proteome profiling study on a unique set of CSF samples from (severe) preeclamptic patients and normotensive pregnant women
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No straight lines – young women’s perceptions of their mental health and wellbeing during and after pregnancy: a systematic review and meta-ethnography
Background: Young mothers face mental health challenges during and after pregnancy including increased rates of depression compared to older mothers. While the prevention of teenage pregnancy in countries such as the United States and the United Kingdom has been a focus for policy and research in recent decades, the need to understand young women’s own experiences has been highlighted. The aim of this meta-ethnography was to examine young women’s perceptions of their mental health and wellbeing during and after pregnancy to provide new understandings of those experiences.
Methods: A systematic review and meta-ethnographic synthesis of qualitative research was conducted. Seven databases were systematically searched and forward and backward searching conducted. Papers were included if they were from Organisation for Economic Co-operation and Development countries and explored mental health and wellbeing experiences of young mothers (age under 20 in pregnancy; under 25 at time of research) as a primary research question – or where evidence about mental health and wellbeing from participants was foregrounded. Nineteen papers were identified and the Critical Appraisal Skills Programme checklist for qualitative research used to appraise the evidence. Following the seven-step process of meta-ethnography, key constructs were examined within each study and then translated into one another.
Results: Seven translated themes were identified forming a new line of argument wherein mental health and wellbeing was analysed as relating to individual bodily experiences; tied into past and present relationships; underpinned by economic insecurity and entangled with feelings of societal surveillance. There were ‘no straight lines’ in young women’s experiences, which were more complex than dominant narratives around overcoming adversity suggest.
Conclusions: The synthesis concludes that health and social care professionals need to reflect on the operation of power and stigma in young women’s lives and its impact on wellbeing. It adds to understanding of young women’s mental health and wellbeing during and after pregnancy as located in physical and structural factors rather than individual capacities alone
Proteomic alterations in early stage cervical cancer
Laser capture microdissection (LCM) allows the capture of cell types or welldefined structures in tissue. We compared in a semi-quantitative way the proteomes from an equivalent of 8,000 tumor cells from patients with squamous cell cervical cancer (SCC, n = 22) with healthy epithelial and stromal cells obtained from normal cervical tissue (n = 13). Proteins were enzymatically digested into peptides which were measured by high-resolution mass spectrometry and analyzed by "all-ornothing" analysis, Bonferroni, and Benjamini-Hochberg correction for multiple testing. By comparing LCM cell type preparations, 31 proteins were exclusively found in early stage cervical cancer (n = 11) when compared with healthy epithelium and stroma, based on criteria that address specificity in a restrictive "all-or-nothing" way. By Bonferroni correction for multiple testing, 30 proteins were significantly up-regulated between early stage cervical cancer and healthy control, including six members of the MCM protein family. MCM proteins are involved in DNA repair and expected to be participating in the early stage of cancer. After a less stringent Benjamini-Hochberg correction for multiple testing, we found that the abundances of 319 proteins were significantly different between early stage cervical cancer and healthy controls. Four proteins were confirmed in digests of whole tissue lysates by Parallel Reaction
Final report of EURAMET.M.G-K3 regional comparison of absolute gravimeters
The regional key comparison of absolute gravimeters, EURAMET.M.G-K3 and the simultaneously organized additional comparison, was held in Germany at the Geodetic Observatory Wettzell of the German Federal Agency for Cartography and Geodesy in the spring of 2018.Here we present the list of the participants who actually performed measurements during the comparison, the data submitted by the operators as well as the results of the determination of the gravity as a function of height at the comparison sites. The measurement strategy is briefly discussed and the results of the data harmonization is documented. Finally, the results of the constrained least squares adjustment are presented including the degrees of equivalence of each gravimeter and the key comparison reference values.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).Export citation and abstract BibTeX RIS
Conspiracy theory as spatial practice: the case of the Sivas arson attack, Turkey
This article discusses the relationship between conspiratorial thinking and physical space by focusing on the ways conspiracy theories regarding political violence shape and are shaped by the environments in which it is commemorated. Conspiratorial thinking features space as a significant element, but is taken to do so mainly figuratively. In blaming external powers and foreign actors for social ills, conspiracy theorists employ the spatial metaphor of inside versus outside. In perceiving discourses of transparency as the concealment rather than revelation of mechanisms of governance, conspiracy theorists engage the trope of a façade separating the space of power’s formulations from that of its operations. Studying the case of an arson attack dating from 1990s Turkey and its recent commemorations, this article argues that space mediates conspiracy theory not just figuratively but also physically and as such serves to catalyze two of its deadliest characteristics: anonymity and non-linear causality. Attending to this mediation requires a shift of focus from what conspiracy theory is to what it does as a spatial practice
An appeal to the global health community for a tripartite innovation: an ‘‘Essential Diagnostics List,’’ ‘‘Health in All Policies,’’ and ‘‘See-Through 21st Century Science and Ethics"
Diagnostics spanning a wide range of new biotechnologies, including proteomics, metabolomics, and nanotechnology, are emerging as companion tests to innovative medicines. In this Opinion, we present the rationale for promulgating an ‘‘Essential Diagnostics List.’’ Additionally, we explain the ways in which adopting a vision for ‘‘Health in All Policies’’ could link essential diagnostics with robust and timely societal outcomes such as sustainable development, human rights, gender parity, and alleviation of poverty. We do so in three ways. First, we propose the need for a new, ‘‘see through’’ taxonomy for knowledge-based innovation as we transition from the material industries (e.g., textiles, plastic, cement, glass) dominant in the 20th century to the anticipated knowledge industry of the 21st century. If knowledge is the currency of the present century, then it is sensible to adopt an approach that thoroughly examines scientific knowledge, starting with the production aims, methods, quality, distribution, access, and the ends it purports to serve. Second, we explain that this knowledge trajectory focus on innovation is crucial and applicable across all sectors, including public, private, or public–private partnerships, as it underscores the fact that scientific knowledge is a co-product of technology, human values, and social systems. By making the value systems embedded in scientific design and knowledge co-production transparent, we all stand to benefit from sustainable and transparent science. Third, we appeal to the global health community to consider the necessary qualities of good governance for 21st century organizations that will embark on developing essential diagnostics. These have importance not only for science and knowledge based innovation, but also for the ways in which we can build open, healthy, and peaceful civil societies today and for future generations
Ramadan fasting does not adversely affect neuromuscular performances and reaction times in trained karate athletes
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