52 research outputs found

    Automated Point Cloud Correspondence Detection for Underwater Mapping Using AUVs

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    An algorithm for automating correspondence detection between point clouds composed of multibeam sonar data is presented. This allows accurate initialization for point cloud alignment techniques even in cases where accurate inertial navigation is not available, such as iceberg profiling or vehicles with low-grade inertial navigation systems. Techniques from computer vision literature are used to extract, label, and match keypoints between "pseudo-images" generated from these point clouds. Image matches are refined using RANSAC and information about the vehicle trajectory. The resulting correspondences can be used to initialize an iterative closest point (ICP) registration algorithm to estimate accumulated navigation error and aid in the creation of accurate, self-consistent maps. The results presented use multibeam sonar data obtained from multiple overlapping passes of an underwater canyon in Monterey Bay, California. Using strict matching criteria, the method detects 23 between-swath correspondence events in a set of 155 pseudo-images with zero false positives. Using less conservative matching criteria doubles the number of matches but introduces several false positive matches as well. Heuristics based on known vehicle trajectory information are used to eliminate these

    Dopunska prehrana ribljim uljem poboljšala je funkciju jajnika, koncepciju i određene reprodukcijske pokazatelje kod kobila pasmine marvari

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    We investigated the effect of dietary fish oil supplementation on the development of the ovarian follicles, corpus luteum (CL), conceptus and certain reproductive events in Marwari mares, since it is reported to improve reproduction in cows. Accordingly, non-lactating mares (n = 20) were randomly assigned into two groups (10 per group) and fed either the control diet (CTR) or a diet enriched with fish oil (FOS) to supplement n-3 polyunsaturated fatty acids (PUFA) at the rate of 64 mg/kg body weight/day for 70 days or until 45 days post-ovulation in the mares that became pregnant. Estrus was detected using a teaser and insemination was performed using frozen thawed semen in the experimental mares. Development of the ovarian follicle, CL and conceptus were recorded using trans-rectal ultrasonography. Plasma concentrations of progesterone and estradiol were estimated by radioimmunoassay. In the FOS group, the diameter of the largest follicle from day 4 of estrus until ovulation, and the diameter of the CL on day 7 post-ovulation (D7PO) were greater (P<0.05). However, on day 15 post-ovulation (D15PO), the CL diameter increased significantly in the pregnant mares. Dietary fish oil significantly improved the development of the embryo as evidenced by an increase in the diameter of the embryonic vesicle on day 15 post-ovulation (D15PO), and the embryo proper on day 28 post ovulation (D28PO). Further, the mean plasma estradiol concentration was higher on the day of estrus onset (P<0.05) and day 4 of estrus (P<0.01) in the FOS group. Similarly, dietary fish oil significantly increased the plasma progesterone on D15PO in the pregnant mares (P<0.01). Although the duration of estrus was shorter by 19 hours (P<0.05), the length of the estrous cycle did not vary in the FOS group. A non-significant increase in the pregnancy rate was observed in the mares that received fish oil. It was concluded that dietary fish oil supplementation improved ovarian function and embryonic development in the Marwari mares.Na temelju prethodnih izvješća o poboljšanju reprodukcije krava, kod kobila pasmine marvari istražili smo učinak ribljeg ulja kao prehrambenog dodatka na razvoj folikula jajnika, žutog tijela, koncepcije i određenih reprodukcijskih pokazatelja. U skladu s ciljem, 20 kobila koje nisu bile u laktaciji je metodom slučajnog izbora podijeljeno u dvije skupine s po 10 kobila. Za razliku od kontrolne skupine, kobile u eksperimentalnoj skupini hranjene su obrokom obogaćenim ribljim uljem u obliku dodatka koji je sadržavao n-3 polinezasićene masne kiseline (PUFA), u dnevnoj količini od 64 mg na jedan kg tjelesne mase. Eksperiment je trajao 70 dana, odnosno za kobile koje su ostale gravidne do 45 dana nakon ovulacije. Estrus je praćen teaserom, a osjemenjivanje je provedeno zamrznutim sjemenom. Razvoj folikula jajnika i žutih tijela te gravidnosti praćeni su transrektalnim ultrazvukom. Koncentracija progesterona i estradiola u plazmi procijenjena je radioimunološkom metodom. U eksperimentalnoj skupini utvrđen je veći (P<0,05) promjer najvećeg folikula od 4. dana estrusa do ovulacije i veći promjer žutog tijela 7. dan nakon ovulacije. No, 15. dan nakon ovulacije promjer žutih tijela bio je signifikantno povećan kod gravidnih kobila. Obrok obogaćen ribljim uljem signifikantno je poboljšao razvoj embrija, što se očitovalo povećanjem promjera embrionalne vezikule 15. dan nakon ovulacije i povećanjem embrija 28. dan nakon ovulacije. Nadalje, u eksperimentalnoj skupini kobila srednja koncentracija estradiola u plazmi bila je veća na dan početka estrusa (P<0,05) i 4. dan estrusa (P<0,01). Slično tome, obrok obogaćen ribljim uljem kod gravidnih je kobila signifikantno (P<0,01) povećao progesteron u plazmi 15. dan nakon ovulacije. U kobila eksperimentalne skupine je, uz varijacije estrusnog ciklusa, utvrđeno i za 19 sati kraće trajanje estrusa (P<0,05). Povećana stopa gravidnosti kod kobila dohranjivanih ribljim uljem nije bila signifikantna. Zaključeno je da je hranidba s dodatkom ribljeg ulja kod kobila pasmine marvari poboljšala funkciju jajnika i razvoj embrija

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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