6,173 research outputs found

    Adding Value: Certified Coffee Trade in North America

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    Coffee is the leading agricultural sector in terms of both the number and frequent use of social and environmental certification. This fast-growing category of certified sustainable coffees has emerged from almost negligible quantities in the late 1990s to approximately 4% of global green coffee exports in 2006 making it a multi-billion dollar segment of the industry. The US and Canada account for over one quarter of global coffee imports in value. Their consumers are increasingly attentive to the social, economic, and environmental aspects of coffee production as evidenced by the significant expansion of certified coffees into both gourmet and mass market channels. This chapter covers the market development and current statistics of all the certified sustainable coffees in North America including volumes, value, premiums, and their general trends at the global level.organic; fair trade; eco-friendly; Rainforest Alliance; Utz; certified; coffee; commodities; supply chain; sustainable; markets

    Classification of Intensity-Modulated Proton Therapy Plans

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    Abstract Title: Classification of IMPT Plans Purpose: Create a method to aid physicists and dosimetrists in the classification of Intensity Modulated Proton Therapy treatment plans. Method: A Python program was developed to read structure sets and dose grids from radiation treatment plans. The program outputs field-specific histograms of the number of voxels within the planning target volume that received dose and normalizes each histogram to the percent volume of the target that received each field’s contribution of the total dose. It then determines the number of Gaussian distributions in each histogram, which serves as an initial classification metric, and calculates additional metrics, including the width and maximum dose in each distribution, and the rate at which the number of voxels decrease per change in dose. 49 patients were analyzed, and compared to data from a standard Single-Field Uniform Dose (SFUD) treatment plan and assessed for similarity. Results: The program can classify hybrid treatment plans by assigning them a score based on calculated metrics that represent their correlation with a standard SFUD treatment plan. Conclusions: The program and its outputs can aid in improved classification and differentiation of hybrid treatment plans to facilitate the precision of patient and target volume positioning

    Infection of human cytomegalovirus in cultured human gingival tissue.

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    BackgroundHuman cytomegalovirus (HCMV) infection in the oral cavity plays an important role in its horizontal transmission and in causing viral-associated oral diseases such as gingivitis. However, little is currently known about HCMV pathogenesis in oral mucosa, partially because HCMV infection is primarily limited to human cells and few cultured tissue or animal models are available for studying HCMV infection.ResultsIn this report, we studied the infection of HCMV in a cultured gingival tissue model (EpiGingival, MatTek Co.) and investigated whether the cultured tissue can be used to study HCMV infection in the oral mucosa. HCMV replicated in tissues that were infected through the apical surface, achieving a titer of at least 300-fold at 10 days postinfection. Moreover, the virus spread from the apical surface to the basal region and reduced the thickness of the stratum coreum at the apical region. Viral proteins IE1, UL44, and UL99 were expressed in infected tissues, a characteristic of HCMV lytic replication in vivo. Studies of a collection of eight viral mutants provide the first direct evidence that a mutant with a deletion of open reading frame US18 is deficient in growth in the tissues, suggesting that HCMV encodes specific determinants for its infection in oral mucosa. Treatment by ganciclovir abolished viral growth in the infected tissues.ConclusionThese results suggest that the cultured gingival mucosa can be used as a tissue model for studying HCMV infection and for screening antivirals to block viral replication and transmission in the oral cavity

    A Novel Classification Method of Hybrid Proton PBS Plans using DVH based Metrics

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    Proton Pencil-Beam Scanning treatment plans are optimized using Single-Field Uniform Dose (SFUD), Multi-Field Optimization (MFO), or a combination of the two techniques into a Hybrid plan. In this study, we develop a method to evaluate plans using metrics applied to field-specific differential dose volume histograms (DVHs) from various treatment areas. An application was developed to create normalized differential DVHs of the primary target volume for each field in a proton PBS treatment plan, and used five metrics to create a final ranking system for 235 patients plans. The results were then compared to their initially selected optimization technique, compared across treatment locations, and ran through statistical and machine-learning algorithms to test the validity of the ranking criteria. Out of the 235 patient plans, our system reclassified 33 plans as MFO, 57 Hybrid, and 145 SFUD. Statistical analyses using ANOVA and T-test assuming unequal variances showed all values to be significantly different, and various clustering and re-classification methods proved our ranking system to be a more accurate representation of the treatment plans than the initial automatic optimization

    The Use of e-Learning Course during the COVID-19: A Systems Thinking Approach

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    In the era of theInternet, most educators have been supported by powerful tools ranging from e-books and e-learning sites to cloud services, and students’ learning environment has been a mix between traditional study (in class) and e-learning through some kind of online learning platform. Due to the uncertainty of the rapidly changing COVID-19 situation, all colleges and universities have to shutter their physical campuses and move their courses to remote and online formats hastily. This prompted many to wonder if all of the faculty are ready and qualified to teach online courses and/or if all of the students are ready to learn in the comprehensive online environment. If not, what ultimate impact will be to our higher education during this national emergency virus pandemic since there is no choice but depend on where they sit currently, not to mention the negative reviews and concerns regarding the online education. To make this transfer seamlessly and conflict mitigation, this paper applied systems thinking for an e-Learning course and proposed a flexible grading method for an e-learning environment, which will enhance students’ grades by allowing students to control their own study paces and the amount of efforts spent in the course, which can bring a successful online learning experience

    Determining the Student Services which Align with Undergraduate Student Expectations A Study of Student Perceptions and University Service Delivery

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    Extant research demonstrates that student support services are a vital link in the success of students and a major component in student per- sistence to graduation. This paper reports the results of an empirical study examining enrolled undergraduate student attitudes and expec- tations regarding student services at two-similarly-sized universities in a major metropolitan area in the southwestern United States. Using survey data and a sample of several hundred students at each school, it analyzes their knowledge of and attitudes about student services, such as health services, career counseling, computer laboratories, student organizations and clubs, and sporting events. This study compares student perspectives at private versus public universities and further analyzes possible differing student needs and expectations that may occur among various student demographic groups. The results of this study are important for several reasons. First, it compares student and administrator perspectives on university services to see if they are similar or if there are possible differences in their views. Since the data informs universities about student attitudes and expectations, the data can help universities to do a better job in aligning services to student perceived needs. Second, the study tests the view that students at private universities may have higher expectations of services versus public university students, and then we explore possible differences between various student demographic groups, clarifying how the needs and expectations may differ among these demographic groups. Finally, the results can help universities to determine the services that are viewed as most critical and invest in those services which are more successfully attracting and retaining those students
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