Rapid exploration with multi-rotors: A frontier selection method for high speed flight

Exploring and mapping previously unknown environments while avoiding collisions with obstacles is a fundamental task for autonomous robots. In scenarios where this needs to be done rapidly, multi-rotors are a good choice for the task, as they can cover ground at potentially very high velocities. Flying at high velocities, however, implies the ability to rapidly plan trajectories and to react to new information quickly. In this paper, we propose an extension to classical frontier -based exploration that facilitates exploration at high speeds. The extension consists of a reactive mode in which the multi-rotor rapidly selects a goal frontier from its field of view. The goal frontier is selected in a way that minimizes the change in velocity necessary to reach it. While this approach can increase the total path length, it significantly reduces the exploration time, since the multi-rotor can fly at consistently higher speeds

Is it appropriate for Korean women to adopt the 2009 Institute of Medicine recommendations for gestational weight gain?

<div><p>Background</p><p>The 2009 Institute of Medicine (IOM) guidelines for gestational weight gain (GWG) are intended for use among women in the United States. Little data are available on whether the 2009 IOM recommendations can be applied to Asian women. This study aimed to evaluate whether the recommendations are related to adverse pregnancy outcomes in Korean pregnant women.</p><p>Methods and findings</p><p>A retrospective cohort study was conducted for all singleton-pregnant women at a university hospital in Korea. After classifying the enrolled women into four Korean pre-pregnancy body mass index (BMI) categories, the risk of adverse pregnancy outcomes were analyzed for women who gained inadequate or excessive GWG based on 2009 IOM recommendations. Of 7,843 pregnancies, 64.0% of women had normal pre-pregnancy BMI and 42.7% achieved optimal GWG. Across all BMI categories, adverse pregnancies outcomes such as small for gestational age (SGA), large for gestational age (LGA), preterm birth, preeclampsia, and cesarean due to dystocia were significantly associated with GWG (all <i>P</i> ≤ 0.001).Women with normal BMI who gained inadequate weight were more likely to develop SGA and preterm birth and less likely to develop LGA (adjusted odds ratio (aOR) 2.21, 1.33, and 0.54, respectively). Whereas, women with normal BMI who gained excessive weight were more likely to develop LGA, preterm birth, preeclampsia, and cesarean section due to dystocia (aOR 2.10, 1.33, 1.37, and 1.37, respectively) and less likely to develop SGA (aOR 0.60).</p><p>Conclusions</p><p>It is tolerable for Korean women to follow recommended GWG from the 2009 IOM guidelines to decrease adverse pregnancy outcomes. This will be helpful for antenatal care on GWG not only for Korean pregnant women, but also other Asian women who have lower BMI criteria than Caucasian women.</p></div

Baseline characteristics and pregnancy outcomes by pre-pregnancy body mass index category.

<p>Baseline characteristics and pregnancy outcomes by pre-pregnancy body mass index category.</p

Flow diagram of study inclusion.

<p>Flow diagram of study inclusion.</p

Pregnancy outcomes by gestational weight gain among all women.

<p>Pregnancy outcomes by gestational weight gain among all women.</p

Multivariate analysis of pregnancy outcomes by pre-pregnancy body mass index category among women who gained inadequate weight during pregnancy.

<p>Multivariate analysis of pregnancy outcomes by pre-pregnancy body mass index category among women who gained inadequate weight during pregnancy.</p

Gestational weight gain according to pre-pregnancy body mass index category.

<p>Gestational weight gain according to pre-pregnancy body mass index category.</p

Analysis of Sequence Variation and Risk Association of Human Papillomavirus 52 Variants Circulating in Korea

<div><p>Introduction</p><p>Human papillomavirus (HPV) 52 is a carcinogenic, high-risk genotype frequently detected in cervical cancer cases from East Asia, including Korea.</p><p>Materials and Methods</p><p>Sequences of HPV52 detected in 91 cervical samples collected from women attending Seoul St. Mary’s Hospital were analyzed. HPV52 genomic sequences were obtained by polymerase chain reaction (PCR)-based sequencing and analyzed using Seq-Scape software, and phylogenetic trees were constructed using MEGA6 software.</p><p>Results</p><p>Of the 91 cervical samples, 40 were normal, 22 were low-grade lesions, 21 were high-grade lesions and 7 were squamous cell carcinomas. Four HPV52 variant lineages (A, B, C and D) were identified. Lineage B was the most frequently detected lineage, followed by lineage C. By analyzing the two most frequently detected lineages (B and C), we found that distinct variations existed in each lineage. We also found that a lineage B-specific mutation K93R (A379G) was associated with an increased risk of cervical neoplasia.</p><p>Conclusions</p><p>To our knowledge, we are the first to reveal the predominance of the HPV52 lineages, B and C, in Korea. We also found these lineages harbored distinct genetic alterations that may affect oncogenicity. Our findings increase our understanding on the heterogeneity of HPV52 variants, and may be useful for the development of new diagnostic assays and therapeutic vaccines.</p></div

HPV52 variant lineage distribution of study samples.

<p>(A) Lineages A (sublineages: A1 and A2), B (sublineage: B2), C (sublineage: C2) and D were detected. (B) A phylogenetic tree was constructed from 57 HPV52 variants using concatenated L1, LCR, E6 and E7. A maximum-likelihood tree was constructed using the program, MEGA6. Bootstrap values of key nodes generated by 1,000 resamplings are shown. The length of the scale bar represents 0.005 substitutions per nucleotide position. To root the tree, HPV67 prototype sequences (NCBI accession no. NC_004710) were set as outgroup. The GenBank accession no. of study samples are KY077824-KY077901.</p