3,323 research outputs found

    A perception and manipulation system for collecting rock samples

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    An important part of a planetary exploration mission is to collect and analyze surface samples. As part of the Carnegie Mellon University Ambler Project, researchers are investigating techniques for collecting samples using a robot arm and a range sensor. The aim of this work is to make the sample collection operation fully autonomous. Described here are the components of the experimental system, including a perception module that extracts objects of interest from range images and produces models of their shapes, and a manipulation module that enables the system to pick up the objects identified by the perception module. The system was tested on a small testbed using natural terrain

    Injection of hydrogen and vacancy-type defects during dissolution of aluminum

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    Formation of interfacial nanoscale voids in Al during room-temperature caustic corrosion was characterized by positron annihilation spectroscopy (PAS) and compared with measurements of deuterium absorption using secondary ion mass spectrometry (SIMS). The hypothesis was investigated that voids are created from vacancy-hydrogen (Vac-H) defects introduced during corrosion. Evidence for both mobile and immobile forms of absorbed hydrogen was obtained, the latter present within distances of 50 nm from the metal-oxide interface, where voids were also found. During corrosion, the immobile hydrogen was found only during discrete 1-2 min intervals of time separated by periods of 1-2 min when it was not present. Model calculations suggested that this transient behavior is consistent with repeated nucleation and dissolution of clusters of Vac-H defects. Only some aspects of the time-dependence of the void concentration from PAS corresponded with that of absorbed hydrogen; the former is believed to be influenced by metallic impurities

    A study of 2 GHz electromagnetic wave propagation over optical paths in three geographical regions of the United States

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    Statistical correlation between optical microwave propagation reliability, fade margin, path length, and geographic locatio

    The Civic Functionality of Campaigns: Voter Competence, Mobilization, and Salience

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    Leading to an election, television screens are consumed by the faces of candidates; radio shows are teeming with voices of campaign professionals; analysts and voters are being endlessly presented with new information, policy standpoints, and poll numbers. In this busy day and age it can be difficult, inconvenient, and time consuming for voters to seek out political knowledge for themselves. Campaigns can be seemingly interminable and it is far easier for a voter to take their information from these ongoing campaigns than to pursue the information from various sources on their own. Campaigns supply voters with data, analyses, and platforms that can aid them in mobilizing and casting an informed vote. Our question is do campaigns really matter and do they actually affect the amount of knowledge that a voter. We also look to see if campaigns encourage voter mobilization through various forms of media like social media and news or if they have no effect on voter turnout at the polls

    Identification of Birds through DNA Barcodes

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    Short DNA sequences from a standardized region of the genome provide a DNA barcode for identifying species. Compiling a public library of DNA barcodes linked to named specimens could provide a new master key for identifying species, one whose power will rise with increased taxon coverage and with faster, cheaper sequencing. Recent work suggests that sequence diversity in a 648-bp region of the mitochondrial gene, cytochrome c oxidase I (COI), might serve as a DNA barcode for the identification of animal species. This study tested the effectiveness of a COI barcode in discriminating bird species, one of the largest and best-studied vertebrate groups. We determined COI barcodes for 260 species of North American birds and found that distinguishing species was generally straightforward. All species had a different COI barcode(s), and the differences between closely related species were, on average, 18 times higher than the differences within species. Our results identified four probable new species of North American birds, suggesting that a global survey will lead to the recognition of many additional bird species. The finding of large COI sequence differences between, as compared to small differences within, species confirms the effectiveness of COI barcodes for the identification of bird species. This result plus those from other groups of animals imply that a standard screening threshold of sequence difference (10× average intraspecific difference) could speed the discovery of new animal species. The growing evidence for the effectiveness of DNA barcodes as a basis for species identification supports an international exercise that has recently begun to assemble a comprehensive library of COI sequences linked to named specimens

    What about the partner? -factors associated with patient-perceived partner dyspareunia in men with Peyronie\u27s disease

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    Background: Limited data are available on how partners of men with Peyronie\u27s disease (PD) are affected by the disease. We sought to characterize PD patients whose curvatures result in pain for their partners during penetrative intercourse. Methods: We queried a database of all men undergoing initial evaluation for PD at a single clinic between March 2014 and June 2016. Patients were administered a questionnaire regarding sexual health concerns with domains including erectile dysfunction, ejaculatory dysfunction, libido, and penile curvature. In the penile curvature section, patients were specifically asked: Does the curvature cause your partner any pain during penetrative intercourse? (Y/N). Patients\u27 partners were not directly evaluated for conditions associated with dyspareunia. Additionally, patients interested in treatment for PD underwent objective curve assessment after intracavernosal injection of erectogenic medications along with penile duplex Doppler ultrasound. Statistical analysis was performed to identify differences in clinicopathologic variables and patient-responses to questionnaire prompts between patients who did and did not report partner pain with intercourse. Results: A total of 322 patients with information available on partner pain were included in the study. Patients who reported partner pain had significantly higher subjective erectile rigidity (mean 5.9/10 Conclusions: Men with superior erectile function, higher degrees of penile curvature and ventral curvatures were more likely to report partner pain during penetrative intercourse. These specific disease characteristics reported in this series may assist clinicians in identifying men who are more motivated to select more invasive therapies

    jMOTU and Taxonerator: Turning DNA Barcode Sequences into Annotated Operational Taxonomic Units

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    BACKGROUND: DNA barcoding and other DNA sequence-based techniques for investigating and estimating biodiversity require explicit methods for associating individual sequences with taxa, as it is at the taxon level that biodiversity is assessed. For many projects, the bioinformatic analyses required pose problems for laboratories whose prime expertise is not in bioinformatics. User-friendly tools are required for both clustering sequences into molecular operational taxonomic units (MOTU) and for associating these MOTU with known organismal taxonomies. RESULTS: Here we present jMOTU, a Java program for the analysis of DNA barcode datasets that uses an explicit, determinate algorithm to define MOTU. We demonstrate its usefulness for both individual specimen-based Sanger sequencing surveys and bulk-environment metagenetic surveys using long-read next-generation sequencing data. jMOTU is driven through a graphical user interface, and can analyse tens of thousands of sequences in a short time on a desktop computer. A companion program, Taxonerator, that adds traditional taxonomic annotation to MOTU, is also presented. Clustering and taxonomic annotation data are stored in a relational database, and are thus amenable to subsequent data mining and web presentation. CONCLUSIONS: jMOTU efficiently and robustly identifies the molecular taxa present in survey datasets, and Taxonerator decorates the MOTU with putative identifications. jMOTU and Taxonerator are freely available from http://www.nematodes.org/

    Association between the inflammatory potential of diet and stress among female college students

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    A pro-inflammatory diet may have an adverse influence on stress and inflammatory biomarker levels among college students. The dietary inflammatory index (DII®) is a tool used to assess the inflammatory potential of a diet. However, evidence for the association between DII and stress is limited. We examined the association between energy-adjusted DII (E-DIITM), high sensitivity-C-reactive protein [hs-CRP], and stress among female college students. This cross-sectional study included 401 randomly selected female students, aged 19-35 years. Data collection included blood, anthropometric measurements, a healthy-history questionnaire, the perceived stress scale (PSS-10), the Saudi food frequency questionnaire (FFQ), and E-DII. Multiple linear regression analyses were used to examine the association between FFQ-derived E-DII score, hs-CRP, and PSS. A higher E-DII score per 1SD (1.8) was associated with a 2.4-times higher PSS score (95% CI: 1.8, 3.1). Higher hs-CRP per 1SD (3.3 mg/L) was associated with a 0.9 (95% CI: 0.7-1.1) times higher PSS score, independent of lifestyle and dietary factors. Our findings indicate that pro-inflammatory diets were highly prevalent among Saudi college students and were associated with higher stress levels. Consideration of the role of stress and focusing on anti-inflammatory foods may be key for healthier dietary habits
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