890 research outputs found
Programming DNA-Based Systems through Effective Molarity Enforced by Biomolecular Confinement
The fundamental concept of effective molarity is observed in a variety of biological processes, such as protein compartmentalization within organelles, membrane localization and signaling paths. To control molecular encountering and promote effective interactions, nature places biomolecules in specific sites inside the cell in order to generate a high, localized concentration different from the bulk concentration. Inspired by this mechanism, scientists have artificially recreated in the lab the same strategy to actuate and control artificial DNA-based functional systems. Here, it is discussed how harnessing effective molarity has led to the development of a number of proximity-induced strategies, with applications ranging from DNA-templated organic chemistry and catalysis, to biosensing and protein-supported DNA assembly
Learning Based on Problems (ABP), Impact of RAEE: A Case Study
Using a case of research as a methodological tool, applied in the research lab with students of the ninth semester of the academic program of chemical engineering (IQ) of the Faculty of chemical sciences and engineering (FCQeI) of the Autonomous University of the State of Morelos (UAEM), analyzed competition to students include scientific concepts acquired, where education is a human process more than verify that cognitive skills according to the approach [1], are developed during the resolution of the case. The results showed that students managed to explain the concepts involved, reflected on his own work and realized what had to be improved. For that, students employed higher order cognitive skills, such as explain, investigate, conclude, argue, make decisions and cognitive skills of low order, such as describing, enunciating, memorize and reproduce
Coffee Production: An Analysis of Opportunities for Competitiveness
This study involved rural properties of the Brazilian Cerrado, which are necessarily consistent with the requirements of good agricultural practices for quality, innovation, and technology in the production and management of properties. Based on the knowledge and information as value-added production factors, we sought to highlight the opportunities for improving competitiveness, and thus a review of the literature on competitiveness, knowledge, and information as a differential factor for production with added value, innovation, and territorial technology as well as entrepreneurship. With the data from the field study, the objective was to show how knowledge and information, applied in production and social capital, can leverage competitiveness. The analyzes carried out using AHP indicate that some initiatives already aid in the promotion of innovation and technology applied to production, making it necessary, however, to encourage knowledge and information among producers and other stakeholders collectively, for the best costs and results. They also point to the low concern of producers with training and other productivity improvement techniques, such as selective harvesting. Authenticated that the producers opt for the sale of their production via commodity, aiming to profit quickly. Reasons for this are, in the non-perception of value added (sales in commodity); in the absence of rural structure for the processing and harvesting of the coffee required for special sale; in the precariousness of collective export agents (cooperatives are dependent on traders) and deficiencies in management for positioning in the properties (most work in scale)
Assessment of Endocrine and Gonadal Condition of Male Largemouth Bass from Lake Mead, Nevada
Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown gonads. Mean fish lengths and weights did not vary between sites or sampling times. Pre-spawn LVB males had lower plasma 11-ketotestosterone (KT), higher estradiol-17β (E2), higher E2/KT ratio, higher hepatosomatic index (ratio of liver to body weight), higher hematocrit values, and higher condition factor compared to OA males. However, no significant differences were evident in the gonadosomatic index (ratio of testes to body weight) of either pre-or post-spawn males from the two sites. In post-spawn males, no significant site-associated differences were detected for any of the parameters measured. Overall, these results suggest the existence of site-specific environmental influences on several indices of endocrine condition and health of pre-spawn male largemouth bass in Lake Mead, and are generally consistent with outcomes from previous studies that suggested the occurrence of altered endocrine and reproductive condition in male common carp from LVB
Stuck in the Past? Rumination-Related Memory Integration
Memories connected to ruminative concerns repetitively capture attention, even in situations designed to alter them. However, recent research on memory updating suggests that memory for benign substitutes (e.g., reinterpretations) might be facilitated by integration with the ruminative memories. As a first approach, two experiments (Ns = 72) mimicked rumination-related memories with rumination-themed stimuli and an imagery task. College undergraduates screened for ruminative status first studied and imaged ruminative cue-target word pairs, and then in a second phase they studied the same cues re-paired with benign targets (along with new and repeated pairs). On the test of cued recall of benign targets, they judged whether each recalled word had been repeated or changed across the two phases (or was new in the second phase). When target changes were not remembered, recall of benign targets revealed proactive interference that was insensitive to ruminative status. However, when participants remembered change and the ruminative targets, their recall of benign targets was facilitated, particularly if they identified as ruminators (Experiment 1). When the test simply asked for recall of either or both targets (Experiment 2), ruminators recalled both targets more frequently than did others. These outcomes suggest that ruminative memories might provide bridges to remembering associated benign memories, such as reinterpretations, under conditions consistent with everyday ruminative retrieval
Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties
We investigate a long-term (26 years, from 1987 to 2013) variability in the
broad spectral line properties of the radio galaxy Arp 102B, an active galaxy
with broad double-peaked emission lines. We use observations presented in Paper
I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of
observations performed in 2012--2013. To explore the BLR geometry, and clarify
some contradictions about the nature of the BLR in Arp 102B we explore
variations in the H and H line parameters during the monitored
period. We fit the broad lines with three broad Gaussian functions finding the
positions and intensities of the blue and red peaks in H and H.
Additionally we fit averaged line profiles with the disc model. We find that
the broad line profiles are double-peaked and have not been changed
significantly in shapes, beside an additional small peak that, from time to
time can be seen in the blue part of the H line. The positions of the
blue and red peaks { have not changed significantly during the monitored
period. The H line is broader than H line in the monitored
period. The disc model is able to reproduce the H and H broad
line profiles, however, observed variability in the line parameters are not in
a good agreement with the emission disc hypothesis. It seems that the BLR of
Arp 102B has a disc-like geometry, but the role of an outflow can also play an
important role in observed variation of the broad line properties.Comment: 17 pages, Accepted for publication in A&
Framework for classroom student grading with open-ended questions: A text-mining approach
The purpose of this paper is to present a framework based on text-mining techniques to support teachers in their tasks of grading texts, compositions, or essays, which form the answers to open-ended questions (OEQ). The approach assumes that OEQ must be used as a learning and evaluation instrument with increasing frequency. Given the time-consuming grading process for those questions, their large-scale use is only possible when computational tools can help the teacher. This work assumes that the grading decision is entirely a teacher’s task responsibility, not the result of an automatic grading process. In this context, the teacher is the author of questions to be included in the tests, administration and results assessment, the entire cycle for this process being noticeably short: a few days at most. An attempt is made to address this problem. The method is entirely exploratory, descriptive and data-driven, the only data assumed as inputs being the texts of essays and compositions created by the students when answering OEQ for a single test on a specific occasion. Typically, the process involves exceedingly small data volumes measured by the power of current home computers, but big data when compared with human capabilities. The general idea is to use software to extract useful features from texts, perform lengthy and complex statistical analyses and present the results to the teacher, who, it is believed, will combine this information with his or her knowledge and experience to make decisions on mark allocation. A generic path model is formulated to represent that specific context and the kind of decisions and tasks a teacher should perform, the estimated results being synthesised using graphic displays. The method is illustrated by analysing three corpora of 126 texts originating in three different real learning contexts, time periods, educational levels and disciplines.info:eu-repo/semantics/publishedVersio
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