199 research outputs found
Seismic assessment of the Matera cathedral
This paper presents the seismic assessment of the Cathedral of Matera, in southern Italy, to determine the capacity of the structure when subjected to earthquakes. This church dates back to the 13th century and is one of the most representative monuments of the Apulian Romanesque architecture. Within the context of the evaluation of the seismic response of the cathedral, modal identification tests were performed in order identify and characterize the main dynamic properties of the structure. The results of these tests were used to develop a representative finite element model, which is able to provide the response to seismic actions. A pushover analysis was performed to characterize the seismic behavior of the structure. The results of the seismic analyses on the cathedral show that its vulnerability is high, being the transversal direction the less stiff and resistant. Elements as the nave and the façade, along with the bell tower, might be the most vulnerable to seismic actions. Additionally, it was observed that components as the trusses of the central nave strongly modify the seismic response and capacity of the structure. Apparently, the structure might not be able to withstand a strong earthquake from the region or might present several damage after one. Hence, it is recommendable to perform further studies about the seismic behavior, especially of the most vulnerable elements.The authors would like to acknowledge the University of Minho for supporting the experimental campaign. Thanks is also extended to Dr. Nuno Mendes, University of Minho, for his guidance and help for performing the in-situ tests on the cathedral. The authors would also like to thank to the ELARCH project number 552129-EM-1-2014-1-IT-ERASMUS MUNDUS-EMA 21 for funding the graduate studies of the first author
The IMSI procedure improves poor embryo development in the same infertile couples with poor semen quality: A comparative prospective randomized study
<p>Abstract</p> <p>Background</p> <p>Sperm of poor quality can negatively affect embryo development to the blastocyst stage. The aim of this comparative prospective randomized study was to evaluate the role of an intracytoplasmic morphologically selected sperm injection (IMSI) in the same infertile couples included in the programme of intracytoplasmic sperm injection (ICSI) due to their indications of male infertility which had resulted in all arrested embryos following a prolonged 5-day culture in previous ICSI cycles.</p> <p>Methods</p> <p>Couples exhibiting poor semen quality and with all arrested embryos following a prolonged 5-day culture in previous ICSI cycles were divided into two groups: <it>Group 1: IMSI group </it>(n = 20) with IMSI performed in a current attempt and <it>Group 2: ICSI group </it>(n = 37) with a conventional ICSI procedure performed in a current attempt of <it>in vitro </it>fertilization. Fertilization rate, embryo development, implantation, pregnancy and abortion rates were compared between current IMSI and conventional ICSI procedures, and with previous ICSI attempts.</p> <p>Results</p> <p>The <it>IMSI group </it>was characterized by a higher number of blastocysts per cycle than the <it>ICSI group </it>(0.80 vs. 0.65) after a prolonged 5-day embryo culture. There was a significantly lower number of cycles with all arrested embryos and cycles with no embryo transfer in the <it>IMSI group </it>versus the <it>ICSI group </it>(0% vs. 27.0%, p = 0.048). After the transfer of embryos at the blastocyst or morula stage (on luteal day 5) a tendency toward higher implantation and pregnancy rates per cycle was achieved in the <it>IMSI group </it>compared to the <it>ICSI group </it>(17.1% vs. 6.8%; 25.0% vs. 8.1%, respectively), although not statistically significant. After IMSI, all pregnancies achieved by the blastocyst transfer were normally on-going, whereas after ICSI, two of three pregnancies ended in spontaneous abortion. After IMSI, two pregnancies were also achieved by the morula stage embryos, whereas after the conventional ICSI procedure, embryos at the morula stage did not implant.</p> <p>Conclusions</p> <p>The IMSI procedure improved embryo development and the laboratory and clinical outcomes of sperm microinjection in the same infertile couples with male infertility and poor embryo development over the previous ICSI attempts.</p
Slow oocyte freezing and thawing in couples with no sperm or an insufficient number of sperm on the day of in vitro fertilization
Articulated Model Registration of MRI/X-Ray Spine Data
Collection : Lecture Notes in Computer Science ; vol. 6112This paper presents a method based on articulated models for the registration of spine data extracted from multimodal medical images of patients with scoliosis. With the ultimate aim being the development of a complete geometrical model of the torso of a scoliotic patient, this work presents a method for the registration of vertebral column data using 3D magnetic resonance images (MRI) acquired in prone position and X-ray data acquired in standing position for five patients with scoliosis. The 3D shape of the vertebrae is estimated from both image modalities for each patient, and an articulated model is used in order to calculate intervertebral transformations required in order to align the vertebrae between both postures. Euclidean distances between anatomical landmarks are calculated in order to assess multimodal registration error. Results show a decrease in the Euclidean distance using the proposed method compared to rigid registration and more physically realistic vertebrae deformations compared to thin-plate-spline (TPS) registration thus improving alignment.IRS
Structural assessment and seismic vulnerability of earthen historic structures. Application of sophisticated numerical and simple analytical models
Adobe constructions account for a significant portion of the built heritage, associated with early building techniques, material accessibility and low-cost. Nonetheless, adobe buildings, due to their low mechanical properties and overturning resistance, are subject to early structural damage, such as cracking, separation of structural elements and, possibly, collapse in areas of high seismic hazard. The lack of maintenance and absence of adequate retrofitting techniques usually intensifies the loss of historic fabric. The current paper, aims at the structural assessment and seismic safety, in current conditions, of the Church of Kuno Tambo, a religious adobe structure of the 17th century, in Cusco region, in Peru. The inspection and diagnosis involved sonic testing and damage mapping, while ambient vibration tests revealed the modal response of the structure. The assessment of seismic vulnerability, together with the necessity of retrofitting measures were verified through nonlinear static and pushover parametric analyses, complemented with a macro-block limit analysis and a performance based assessment, under local seismic criteria. A more realistic response from dynamically induced ground motions was performed, by a nonlinear time history analysis, according to the Eurocode 8 framework. Through an integrated approach, in situ inspection, testing, numerical and analytical modelling are associated under the scope of reproducing the existing structural damage, the sequence of inelastic behavior and verification of the necessity of retrofitting measures.The current work is part of the Seismic Retrofitting Project, of the Getty Conservation Institute and was partly supported by FCT (Portuguese Foundation for Science and Technology), within the INFRARISK PhD program and ISISE, project UID/ECl/04029/2013.info:eu-repo/semantics/publishedVersio
Biomedical imaging research opportunities workshop IV: A white paper
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134967/1/mp5838.pd
A semi-random field finite element method to predict the maximum eccentric compressive load for masonry prisms
An accurate prediction of the compressive strength of masonry is essential both for the analysis of existing structures and the construction of new masonry buildings. Since experimental material testing of individual masonry components (e.g. masonry unit and mortar joints) often produces highly variable results, this paper presents a numerical modelling based approach to address the associated uncertainty for the prediction of the maximum compressive load of masonry prisms. The method considers numerical model to be semi-random for a masonry prism by adopting a Latin Hyper cube simulation method used in conjunction with a parametric finite element model of the individual masonry prism. The proposed method is applied to two types of masonry prisms (using hollow blocks and solid clay bricks), for which experimental testing was conducted as part of the 9th International Masonry Conference held at Guimarães in July 2014. A Class A prediction (presented before the tests were conducted) was generated for the two masonry prisms according to the proposed methodology, and the results were compared to the final experimental testing results. The root mean square deviation of the method for prediction of eccentric compressive strength of both types of prisms differed by only 2.2KN, thereby demonstrates the potential for this probabilistic approach.This work was sponsored with funding from the European Union's Grant ERC StG 2012-307836-RETURN. The experimental testing program and student blind competition was sponsored by the European Lime Association (EuLA)
Oocyte and ovarian tissue cryopreservation in European countries : statutory background, practice, storage and use
STUDY QUESTION: What is known in Europe about the practice of oocyte cryopreservation (OoC), in terms of current statutory background, funding conditions, indications (medical and ‘non-medical’) and specific number of cycles? SUMMARY ANSWER: Laws and conditions for OoC vary in Europe, with just over half the responding countries providing this for medical reasons with state funding, and none providing funding for ‘non-medical’ OoC. WHAT IS ALREADY KNOWN: The practice of OoC is a well-established and increasing practice in some European countries, but data gathering on storage is not homogeneous, and still sparse for use. Ovarian tissue cryopreservation (OtC) is only practiced and registered in a few countries. STUDY DESIGN, SIZE, AND DURATION: A transversal collaborative survey on OoC and OtC, was designed, based on a country questionnaire containing information on statutory or professional background and practice, as well as available data on ovarian cell and tissue collection, storage and use. It was performed between January and September 2015. PARTICIPANTS/MATERIALS, SETTING AND METHODS: All ESHRE European IVF Monitoring (EIM) consortium national coordinators were contacted, as well as members of the ESHRE committee of national representatives, and sent a questionnaire. The form included national policy and practice details, whether through current existing law or code of practice, criteria for freezing (age, health status), availability of funding and the presence of a specific register. The questionnaire also included data on both the number of OoC cycles and cryopreserved oocytes per year between 2010 and 2014, specifically for egg donation, fertility preservation for medical disease, ‘other medical’ reasons as part of an ART cycle, as well as for ‘non-medical reasons’ or age-related fertility decline. Another question concerning data on freezing and use of ovarian tissue over 5 years was added and sent after receiving the initial questionnaire. MAIN RESULTS AND THE ROLE OF CHANCE: Out of 34 EIM members, we received answers regarding OoC regulations and funding conditions from 27, whilst 17 countries had recorded data for OoC, and 12 for OtC. The specific statutory framework for OoC and OtC varies from absent to a strict frame. A total of 34 705 OoC cycles were reported during the 5-year-period, with a continuous increase. However, the accurate description of numbers was concentrated on the year 2013 because it was the most complete. In 2013, a total of 9126 aspirations involving OoC were reported from 16 countries. Among the 8885 oocyte aspirations with fully available data, the majority or 5323 cycles (59.9%) was performed for egg donation, resulting in the highest yield per cycle, with an average of 10.4 oocytes frozen per cycle. OoC indication was ‘serious disease’ such as cancer in 10.9% of cycles, other medical indications as ‘part of an ART cycle’ in 16.1%, and a non-medical reason in 13.1%. With regard to the use of OoC, the number of specifically recorded frozen oocyte replacement (FOR) cycles performed in 2013 for all medical reasons was 14 times higher than the FOR for non-medical reasons, using, respectively, 8.0 and 8.4 oocytes per cycle. Finally, 12 countries recorded storage following OtC and only 7 recorded the number of grafted frozen/thawed tissues. LIMITATIONS, REASONS FOR CAUTION: Not all countries have data regarding OoC collection, and some data came from voluntary collaborating centres, rather than a national authority or register. Furthermore, the data related to use of OoC were not included for two major players in the field, Italy and Spain, where numbers were conflated for medical and non-medical reasons. Finally, the number of cycles started with no retrieval is not available. Data are even sparser for OtC. WIDER IMPLICATIONS OF THE FINDINGS: There is a need for ART authorities and professional bodies to record precise data for practice and use of OoC (and OtC), according to indications and usage, in order to reliably inform all stakeholders including women about the efficiency of both methods. Furthermore, professional societies should establish professional standards for access to and use of OoC and OtC, and give appropriate guidance to all involved. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by ESHRE. There are no conflicts of interest.peer-reviewe
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