483 research outputs found

    Useful Water Quality Information Sources: the Farmers\u27 Point of View

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    Since water quality has become a national priority for research and extension, little has been known regarding farmers\u27 use of information sources

    Communicating With Farmers About Environmental Issues

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    Few studies have focused upon Extension\u27s methods of communicating with farmers about specific issues such as the environment

    Effectiveness of Online Videos to Modify Students\u27 Knowledge and Perceived Barriers Regarding Study Abroad Opportunties

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    The need to increase the number of students participating in study abroad is a goal that higher education must recognize. For ten years, the level of participation among students enrolled in colleges of agricultural sciences has remained at constant level. In a society that is globally interconnected, it is imperative that future graduates comprehend various dimensions of culture, agricultural production, and economy to succeed. The purpose of this study was to determine the effectiveness of online videos to modify students’ knowledge and perceived barriers regarding study abroad opportunities. The objectives of this paper are: 1. Describe the amount of learning obtained through watching study abroad videos; 2. Determine changes to students’ perceived barriers regarding their possible participation in study abroad programs. In order to assess students’ perceptions, three online videos were developed. Videos were based on a semester-long study abroad program in Russia and two study tour programs in Puerto Rico and Brazil, respectively. A quasi-experimental research design was used in this study. One hundred fifty six students from nine sections of the first year seminar participated in the study. In this study, the use of online videos was effective in communicating information and diminishing the perceived barriers to study abroad. Other colleges and programs could use this strategy to promote their international programs. In addition, administrators could use the results of this study to develop online videos to teach content and dispel myths regarding study abroad programs

    Kinetic Relationship between the Voltage Sensor and the Activation Gate in spHCN Channels

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    Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are activated by membrane hyperpolarizations that cause an inward movement of the positive charges in the fourth transmembrane domain (S4), which triggers channel opening. The mechanism of how the motion of S4 charges triggers channel opening is unknown. Here, we used voltage clamp fluorometry (VCF) to detect S4 conformational changes and to correlate these to the different activation steps in spHCN channels. We show that S4 undergoes two distinct conformational changes during voltage activation. Analysis of the fluorescence signals suggests that the N-terminal region of S4 undergoes conformational changes during a previously characterized mode shift in HCN channel voltage dependence, while a more C-terminal region undergoes an additional conformational change during gating charge movements. We fit our fluorescence and ionic current data to a previously proposed 10-state allosteric model for HCN channels. Our results are not compatible with a fast S4 motion and rate-limiting channel opening. Instead, our data and modeling suggest that spHCN channels open after only two S4s have moved and that S4 motion is rate limiting during voltage activation of spHCN channels

    Exterior-Interior Duality for Discrete Graphs

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    The Exterior-Interior duality expresses a deep connection between the Laplace spectrum in bounded and connected domains in R2\mathbb{R}^2, and the scattering matrices in the exterior of the domains. Here, this link is extended to the study of the spectrum of the discrete Laplacian on finite graphs. For this purpose, two methods are devised for associating scattering matrices to the graphs. The Exterior -Interior duality is derived for both methods.Comment: 15 pages 1 figur

    Reducing the Attack Surface of Dynamic Binary Instrumentation Frameworks

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    Malicious applications pose as one of the most relevant issues in today’s technology scenario, being considered the root of many Internet security threats. In part, this owes the ability of malware developers to promptly respond to the emergence of new security solutions by developing artifacts to detect and avoid them. In this work, we present three countermeasures to mitigate recent mechanisms used by malware to detect analysis environments. Among these techniques, this work focuses on those that enable a malware to detect dynamic binary instrumentation frameworks, thus increasing their attack surface. To ensure the effectiveness of the proposed countermeasures, proofs of concept were developed and tested in a controlled environment with a set of anti-instrumentation techniques. Finally, we evaluated the performance impact of using such countermeasures

    Development and Validation of Makeup and Sexualized Clothing Questionnaires

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    Background: Body acceptance programs on college campuses indicated that collegiate women often report feeling pressure to dress in a sexualized manner, and use makeup to enhance beauty. Currently, no quantitative measures exist to assess attitudes and daily behaviors that may arise in response to perceived pressure to wear makeup or dress in a provocative manner. The goal of the current studies was to develop brief self-report questionnaires aimed at assessing makeup and sexualized clothing use and attitudes in young women. Methods: An exploratory factor analysis in a sample of 403 undergraduate women was used in Study 1 to create items to measure the pressure women feel to wear makeup and sexualized clothing. A confirmatory factor analysis (N = 153) was used in Study 2 to confirm the factor structure found in Study 1. An incremental validity analysis was also conducted in Study 2. Across both studies, participants completed online questionnaires. Results: In Study 1, items were developed for two questionnaires to assess perceived pressure to wear makeup and discomfort when not wearing makeup, and perceived pressure to wear sexualized clothing, and body image concerns with regards to sexualized clothing. The exploratory factor analyses revealed Unconfident and Unease scales for the Makeup Questionnaire (MUQ) and Body Dissatisfaction and Pressure scales for the Sexualized Clothing Questionnaire (SCQ). In Study 2, the confirmatory factor analyses confirmed the factor structure for the MUQ and SCQ. The incremental validity analysis revealed that these measures can be used to predict self-objectification and shape and weight concern in women. Conclusion: These studies provide preliminary support for the factor structure of two novel questionnaires aimed at assessing perceived pressure to wear makeup and sexualized clothing

    Single copy shRNA configuration for ubiquitous gene knockdown in mice

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    RNA interference through the expression of small hairpin RNA (shRNA) molecules has become a very promising tool in reverse mouse genetics as it may allow inexpensive and rapid gene function analysis in vivo. However, the prerequisites for ubiquitous and reproducible shRNA expression are not well defined. Here we show that a single copy shRNA-transgene can mediate body-wide gene silencing in mice when inserted in a defined locus of the genome. The most commonly used promoters for shRNA expression, H1 and U6, showed a comparably broad activity in this configuration. Taken together, the results define a novel approach for efficient interference with expression of defined genes in vivo. Moreover, we provide a rapid strategy for the production of gene knockdown mice combining recombinase mediated cassette exchange and tetraploid blastocyst complementation approaches
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