51 research outputs found
Online Informative Path Planning for Active Classification on UAVs
We propose an informative path planning (IPP) algorithm for active
classification using an unmanned aerial vehicle (UAV), focusing on weed
detection in precision agriculture. We model the presence of weeds on farmland
using an occupancy grid and generate plans according to information-theoretic
objectives, enabling the UAV to gather data efficiently. We use a combination
of global viewpoint selection and evolutionary optimization to refine the UAV's
trajectory in continuous space while satisfying dynamic constraints. We
validate our approach in simulation by comparing against standard "lawnmower"
coverage, and study the effects of varying objectives and optimization
strategies. We plan to evaluate our algorithm on a real platform in the
immediate future.Comment: 7 pages, 4 figures, submission to International Symposium on
Experimental Robotics 201
Sampling-based Motion Planning for Active Multirotor System Identification
This paper reports on an algorithm for planning trajectories that allow a
multirotor micro aerial vehicle (MAV) to quickly identify a set of unknown
parameters. In many problems like self calibration or model parameter
identification some states are only observable under a specific motion. These
motions are often hard to find, especially for inexperienced users. Therefore,
we consider system model identification in an active setting, where the vehicle
autonomously decides what actions to take in order to quickly identify the
model. Our algorithm approximates the belief dynamics of the system around a
candidate trajectory using an extended Kalman filter (EKF). It uses
sampling-based motion planning to explore the space of possible beliefs and
find a maximally informative trajectory within a user-defined budget. We
validate our method in simulation and on a real system showing the feasibility
and repeatability of the proposed approach. Our planner creates trajectories
which reduce model parameter convergence time and uncertainty by a factor of
four.Comment: Published at ICRA 2017. Video available at
https://www.youtube.com/watch?v=xtqrWbgep5
Characterization of the human DYRK1A promoter and its regulation by the transcription factor E2F1
<p>Abstract</p> <p>Background</p> <p>Overexpression of the human <it>DYRK1A </it>gene due to the presence of a third gene copy in trisomy 21 is thought to play a role in the pathogenesis of Down syndrome. The observation of gene dosage effects in transgenic mouse models implies that subtle changes in expression levels can affect the correct function of the <it>DYRK1A </it>gene product. We have therefore characterized the promoter of the human <it>DYRK1A </it>gene in order to study its transcriptional regulation.</p> <p>Results</p> <p>Transcription start sites of the human <it>DYRK1A </it>gene are distributed over 800 bp within a region previously identified as an unmethylated CpG island. We have identified a new alternative noncoding 5'-exon of the <it>DYRK1A </it>gene which is located 772 bp upstream of the previously described transcription start site. Transcription of the two splicing variants is controlled by non-overlapping promoter regions that can independently drive reporter gene expression. We found no evidence of cell- or tissue-specific promoter usage, but the two promoter regions differed in their activity and their regulation. The sequence upstream of exon 1A (promoter region A) induced about 10-fold higher reporter gene activity than the sequence upstream of exon 1B (promoter region B). Overexpression of the transcription factor E2F1 increased <it>DYRK1A </it>mRNA levels in Saos2 and Phoenix cells and enhanced the activity of promoter region B three- to fourfold.</p> <p>Conclusion</p> <p>The identification of two alternatively spliced transcripts whose transcription is initiated from differentially regulated promoters regions indicates that the expression of the <it>DYRK1A </it>gene is subject to complex control mechanisms. The regulatory effect of E2F1 suggests that DYRK1A may play a role in cell cycle regulation or apoptosis.</p
Online path planning for autonomous underwater vehicles in unknown environments
We present a framework for planning collision-free paths online for autonomous underwater vehicles (AUVs) in unknown environments. It is composed of three main modules (mapping, planning and mission handler) that incrementally explore the environment while solving start-to-goal queries. We use an octree-based representation of the environment and we extend the optimal rapidly-exploring random tree (RRT*) using concepts of anytime algorithms and lazy collision evaluation, thus including the capability to replan paths according to nearby obstacles perceived during the execution of the mission. To validate our approach, we plan paths for the SPARUS-II AUV, a torpedo-shaped vehicle performing autonomous missions in a 2-dimensional workspace. We demonstrate its feasibility with the SPARUS-II AUV in both simulation and real-world in-water trials
Design and evaluation of an educational course in cultural competence for nursing
The Escola Superior d'Infermeria del Mar proposed to incorporate the skills acquisition of cultural competence in the curricula design of the new Nursing Degree; to get it, an optional course was created (Cultural Competence) within the 3rd quarter of 3rd year. The aim of this study is to evaluate the effectiveness of training for the acquisition of Cultural Competence in nursing students. Is a quasi-experimental pretest-postest design with a single group in two consecutive courses (2011-12/2012-13). Data were collected through an ad-hoc 16 items Likert questionnaire at the beginning (pre-test) and the end of the course (post-test). A total of 43 students participated in the study. Statistically significant differences were observed in two items of the pretest results and no difference in post-test results. To confirm pretest and posttest hypothesis, results were compared after the educational intervention, finding significant differences in all survey items. The design of the course, in which knowledge and skills were worked, appears to be effective in acquiring cultural competence
Spin-orbit torques and magnetization switching in (Bi,Sb)2Te3/Fe3GeTe2 heterostructures grown by molecular beam epitaxy
Topological insulators (TIs) hold promise for manipulating the magnetization of a ferromagnet (FM) through the spin-orbit torque (SOT) mechanism. However, integrating TIs with conventional FMs often leads to significant device-to-device variations and a broad distribution of SOT magnitudes. In this work, we present a scalable approach to grow a full van der Waals FM/TI heterostructure by molecular beam epitaxy, combining the charge-compensated TI (Bi,Sb)2Te3 with 2D FM Fe3GeTe2 (FGT). Harmonic magnetotransport measurements reveal that the SOT efficiency exhibits a non-monotonic temperature dependence and experiences a substantial enhancement with a reduction of the FGT thickness to 2 monolayers. Our study further demonstrates that the magnetization of ultrathin FGT films can be switched with a current density of Jc ∼ 1010 A/m2, with minimal device-to-device variations compared to previous investigations involving traditional FMs.This research has received funding from the European Union’s Horizon 2020 (EU H2020) research and innovation programme under grant agreement 881603 (Graphene Flagship) and was supported by the FLAG-ERA grant MNEMOSYN. ICN2 acknowledges support from the Spanish Ministry of Science and Innovation (MCIN) and Spanish Research Agency (AEI/10.13039/501100011033) under contracts PID2019-111773RB-I00, PCI2021-122035-2A, PID2022-143162OB-I00 (including FEDER funds), and Severo Ochoa CEX2021-001214-S. SPINTEC acknowledges support from the French ANR under contracts ANR-21-GRF1-0005-01 and ANR-20-CE24-0015 (ELMAX). T.G. and R.G. acknowledge support from EU H2020 programme under the Marie Skłodowska-Curie Grant Agreement Nos. 754510 and 840588 (GRISOTO, Marie Sklodowska-Curie fellowship), respectively, and JFS from MCIN/AEI/10.13039/50110001103 under contract RYC2019-028368-I.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001214-S).Peer reviewe
Phase I prognostic online (PIPO): A web tool to improve patient selection for oncology early phase clinical trials
Immunotherapy; Phase 1 trials; Prognostic modelInmunoterapia; Ensayos de fase 1; Modelo pronósticoImmunoteràpia; Assajos de fase 1; Model pronòsticPurpose
Patient selection in phase 1 clinical trials (Ph1t) continues to be a challenge. The aim of this study was to develop a user-friendly prognostic calculator for predicting overall survival (OS) outcomes in patients to be included in Ph1t with immune checkpoint inhibitors (ICIs) or targeted agents (TAs) based on clinical parameters assessed at baseline.
Methods
Using a training cohort with consecutive patients from the VHIO phase 1 unit, we constructed a prognostic model to predict median OS (mOS) as a primary endpoint and 3-month (3m) OS rate as a secondary endpoint. The model was validated in an internal cohort after temporal data splitting and represented as a web application.
Results
We recruited 799 patients (training and validation sets, 558 and 241, respectively). Median follow-up was 21.2 months (m), mOS was 10.2 m (95% CI, 9.3–12.7) for ICIs cohort and 7.7 m (95% CI, 6.6–8.6) for TAs cohort. In the multivariable analysis, six prognostic variables were independently associated with OS – ECOG, number of metastatic sites, presence of liver metastases, derived neutrophils/(leukocytes minus neutrophils) ratio [dNLR], albumin and lactate dehydrogenase (LDH) levels. The phase 1 prognostic online (PIPO) calculator showed adequate discrimination and calibration performance for OS, with C-statistics of 0.71 (95% CI 0.64–0.78) in the validation set. The overall accuracy of the model for 3m OS prediction was 87.2% (95% CI 85%–90%).
Conclusions
PIPO is a user-friendly objective and interactive tool to calculate specific survival probabilities for each patient before enrolment in a Ph1t. The tool is available at https://pipo.vhio.net/.The research leading to these results has received funding from “la Caixa” Foundation (LCF/PR/CE07/50610001). Cellex Foundation for providing research facilities and equipment. This work was supported by the Accelerator Award (UpSMART) from Fundacion Científica – Asociacion Espanola Contra el Cancer (FC -AECC)/ Associazione Italiana per la Ricerca sul Cancro (AIRC) /Cancer Research United Kingdom (CRUK)
Menstrual and Reproductive Factors and Risk of Gastric and Colorectal Cancer in Spain
BACKGROUND:
Sex hormones play a role in gastric cancer and colorectal cancer etiology, however, epidemiological evidence is inconsistent. This study examines the influence of menstrual and reproductive factors over the risk of both tumors.
METHODS:
In this case-control study 128 women with gastric cancer and 1293 controls, as well as 562 female and colorectal cancer cases and 1605 controls were recruited in 9 and 11 Spanish provinces, respectively. Population controls were frequency matched to cases by age and province. Demographic and reproductive data were directly surveyed by trained staff. The association with gastric, colon and rectal cancer was assessed using logistic and multinomial mixed regression models.
RESULTS:
Our results show an inverse association of age at first birth with gastric cancer risk (five-year trend: OR = 0.69; p-value = 0.006). Ever users of hormonal contraception presented a decreased risk of gastric (OR = 0.42; 95%CI = 0.26-0.69), colon (OR = 0.64; 95%CI = 0.48-0.86) and rectal cancer (OR = 0.61; 95%CI = 0.43-0.88). Postmenopausal women who used hormone replacement therapy showed a decreased risk of colon and rectal tumors. A significant interaction of educational level with parity and months of first child lactation was also observed.
CONCLUSION:
These findings suggest a protective role of exogenous hormones in gastric and colorectal cancer risk. The role of endogenous hormones remains unclear
ECS Un gen de respuesta inmediata a la ecdisona, imprescindible para la ecdisis pupal en 'Drosophila melanogaster'
Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai
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