2,483 research outputs found

    Multi-Disciplinary Capstone Project on Self-Replicating 3-D Printer

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    This paper explores the dynamics of a multi-semester multi-disciplinary team approach applied within a traditional senior capstone project that involves strong design and manufacturing components. In addition, the logistics of running a successful senior project will be discussed along with the associated problems of organization within a multi-program environment. The key drivers and motivators behind this paper are, most importantly, that multi-disciplinary teams are very common in industry and that our industrial advisory boards for Electrical Engineering Technology (EET) and Mechanical Engineering Technology (MET) suggested that we do more multi-disciplinary projects. Furthermore, this multi-disciplinary team approach will satisfy the proposed ABET/ETAC outcomes for 2016. The Proposed Revisions to the Program Criteria for Mechanical Engineering Technology and Similarly Named Programs ABET/ETAC outcomes say “The capstone experience, ideally multidisciplinary in nature, must be project based and include formal design, implementation and test processes.” (emphasis added) Faculty searched for a technology that would allow both EET and MET students to contribute equally to the success of the project, and decided upon additive manufacturing. Students have been exposed extensively through formal course material covering 3D printing technology and would be familiar with the operation of 3D printers in general. Therefore, it was reasoned a familiarity with the project goal of designing and constructing a self-replicating 3D printer would give students more confidence in tackling the difficult task of managing an extended project over both the design and manufacture phases, and mastering effective communicate across disciplines. The student team organization mirrors current industry standard operating procedures. First, the team is multidisciplinary, including EET students with programing and circuits skills and MET students with CAD, design, mechanical analysis skills. All students must demonstrate project process skills, utilizing current design for six-sigma procedures. The students learn a standard set of tools to manage the project, as well as synthesize those tools with their discipline specific knowledge. Because of the program curriculum plans, the EET students are involved in the project for two semesters. The MET students have a one semester project course; this enables one group of MET students to design the mechanical system, document their work, and pass it on to a second team for implementation. This was considered a positive based on what is typical in industry, where engineering groups are constantly interfacing. Results include observations of group member dynamics, quality of work, timeliness, budget management, and communication across disciplines. Rubrics to document student achievement of outcomes are used

    Optimality of mutation and selection in germinal centers

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    The population dynamics theory of B cells in a typical germinal center could play an important role in revealing how affinity maturation is achieved. However, the existing models encountered some conflicts with experiments. To resolve these conflicts, we present a coarse-grained model to calculate the B cell population development in affinity maturation, which allows a comprehensive analysis of its parameter space to look for optimal values of mutation rate, selection strength, and initial antibody-antigen binding level that maximize the affinity improvement. With these optimized parameters, the model is compatible with the experimental observations such as the ~100-fold affinity improvements, the number of mutations, the hypermutation rate, and the "all or none" phenomenon. Moreover, we study the reasons behind the optimal parameters. The optimal mutation rate, in agreement with the hypermutation rate in vivo, results from a tradeoff between accumulating enough beneficial mutations and avoiding too many deleterious or lethal mutations. The optimal selection strength evolves as a balance between the need for affinity improvement and the requirement to pass the population bottleneck. These findings point to the conclusion that germinal centers have been optimized by evolution to generate strong affinity antibodies effectively and rapidly. In addition, we study the enhancement of affinity improvement due to B cell migration between germinal centers. These results could enhance our understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio

    Abnormal IgD and IgA1 O-glycosylation in hyperimmunoglobulinaemia D and periodic fever syndrome

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    In order to determine the glycosylation pattern for IgD, and to examine whether there are changes in the pattern of IgD and IgA1 O-glycosylation in patients with hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) during acute febrile attacks and during periods of quiescence, serum was obtained from 20 patients with HIDS and 20 control subjects. In the HIDS group, serum was obtained either during an acute febrile episode (n = 9) or during a period of quiescence (n = 11). The O-glycosylation profiles of native and desialylated IgA1 and IgD were measured in an ELISA-type system using the lectins Helix aspersa and peanut agglutinin, which bind to alternative forms of O-glycan moieties. IgD is more heavily O-galactosylated and less O-sialylated than IgA1 in healthy subjects. HIDS is associated with more extensive O-galactosylation of IgD and a reduction in O-sialylation of both IgD and IgA1. These changes are present both during acute febrile attacks and periods of quiescence. The T cell IgD receptor is a lectin with binding affinity for the O-glycans of both IgD and IgA1. The observed changes in IgD and IgA1 O-glycosylation are likely to have a significant effect on IgD/IgA1–T cell IgD receptor interactions including basal immunoglobulin synthesis, and possibly myeloid IgD receptor-mediated cytokine release

    A Novel Application of Amniotic Membrane in Patients with Bullous Keratopathy

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    To evaluate the efficacy of amniotic membrane in the management of painful bullous keratopathy secondary to the intractable glaucoma and in preventing exposure of drainage devices, we inserted Ahmed valve with amniotic membrane patch graft over the implant itself, and debrided corneal epithelium with amniotic membrane graft over the exposed stroma as a single operation. During the follow-up periods, we monitored vision, intraocular pressure (IOP), presence of ocular pain, and postoperative complications associated with the implants. The mean follow up period was 8.4±3.2 months. IOP was well controlled after the intervention. The preoperative mean IOP was measured as 43.9±9.0 mmHg and lowered to 16.1±1.8 mmHg at the last visit and no complications associated with the implants were noted. Even though the improvement in vision was not prominent, the ocular surface stabilized rapidly and ocular pain associated with bullous keratopathy disappeared soon after surgery. Conclusively the use of amniotic membrane in conjunction with Ahmed valve implantation is an effective way to relieve ocular pain and lessen the chances of complications associated with the implant in patients with intractable glaucoma and bullous keratopathy

    Fruit and vegetable intake and non-communicable diseases among adults aged ≥50 years in low- and middle-income countries

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    OBJECTIVES: The relationship between consuming ≥2 servings of fruits and ≥3 servings of vegetables a day, which has been identified as optimal for health (i.e., adequate fruit/vegetable consumption), and non-communicable diseases (NCDs) in low- and middle-income countries (LMICs) is largely unknown. Therefore, using data from six LMICs, we investigated the independent association between inadequate fruit/vegetable consumption and 12 NCDs, and estimated the prevalence of inadequate fruit/vegetable consumption among people with NCDs. DESIGN AND SETTING: Cross-sectional, nationally representative data from the WHO Study on global AGEing and adult health (SAGE) were analyzed. PARTICIPANTS: Data on 34129 individuals aged ≥50 years were analyzed [mean (SD) age 62.4 (16.0); maximum age 114 years; 52.1% females]. MEASUREMENTS: Information on the number of servings of fruits and vegetables consumed on a typical day was self-reported. Twelve NCDs were assessed. Multivariable logistic regression analysis was conducted. RESULTS: Overall, 67.2% had inadequate fruit/vegetable consumption. Inadequate fruit/vegetable consumption was independently associated with significantly higher odds for chronic lung disease (OR=1.25), diabetes (OR=1.45), hearing problems (OR=1.75), and visual impairment (OR=2.50). The prevalence of inadequate fruit/vegetable consumption was particularly high among people with visual impairment (92.5%), depression (90.5%), asthma (79.8%), and hearing problems (78.4%). CONCLUSION: Promotion of fruit and vegetable consumption (≥2 servings of fruits and ≥3 servings of vegetables a day) in LMICs may lead to prevention of some NCDs (e.g., diabetes, chronic lung disease). Furthermore, people with certain NCDs (e.g., visual impairment, depression) had particularly high prevalence of inadequate fruit/vegetable consumption, and it is thus important to target this population to increase fruit/vegetable consumptio

    Data Assimilation Enhancements to Air Force Weathers Land Information System

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    The United States Air Force (USAF) has a proud and storied tradition of enabling significant advancements in the area of characterizing and modeling land state information. 557th Weather Wing (557 WW; DoDs Executive Agent for Land Information) provides routine geospatial intelligence information to warfighters, planners, and decision makers at all echelons and services of the U.S. military, government and intelligence community. 557 WW and its predecessors have been home to the DoDs only operational regional and global land data analysis systems since January 1958. As a trusted partner since 2005, Air Force Weather (AFW) has relied on the Hydrological Sciences Laboratory at NASA/GSFC to lead the interagency scientific collaboration known as the Land Information System (LIS). LIS is an advanced software framework for high performance land surface modeling and data assimilation of geospatial intelligence (GEOINT) information

    Innovative solutions to sticky situations: Antiadhesive strategies for treating bacterial infections

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    ABSTRACT Bacterial adherence to host tissue is an essential process in pathogenesis, necessary for invasion and colonization and often required for the efficient delivery of toxins and other bacterial effectors. As existing treatment options for common bacterial infections dwindle, we find ourselves rapidly approaching a tipping point in our confrontation with antibiotic-resistant strains and in desperate need of new treatment options. Bacterial strains defective in adherence are typically avirulent and unable to cause infection in animal models. The importance of this initial binding event in the pathogenic cascade highlights its potential as a novel therapeutic target. This article seeks to highlight a variety of strategies being employed to treat and prevent infection by targeting the mechanisms of bacterial adhesion. Advancements in this area include the development of novel antivirulence therapies using small molecules, vaccines, and peptides to target a variety of bacterial infections. These therapies target bacterial adhesion through a number of mechanisms, including inhibition of pathogen receptor biogenesis, competition-based strategies with receptor and adhesin analogs, and the inhibition of binding through neutralizing antibodies. While this article is not an exhaustive description of every advancement in the field, we hope it will highlight several promising examples of the therapeutic potential of antiadhesive strategies.</jats:p

    Adjuvant-specific regulation of long-term antibody responses by ZBTB20

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    The duration of antibody production by long-lived plasma cells varies with the type of immunization, but the basis for these differences is unknown. We demonstrate that plasma cells formed in response to the same immunogen engage distinct survival programs depending on the adjuvant. After alum-adjuvanted immunization, antigen-specific bone marrow plasma cells deficient in the transcription factor ZBTB20 failed to accumulate over time, leading to a progressive loss of antibody production relative to wild-type controls. Fetal liver reconstitution experiments demonstrated that the requirement for ZBTB20 was B cell intrinsic. No defects were observed in germinal center numbers, affinity maturation, or plasma cell formation or proliferation in ZBTB20-deficient chimeras. However, ZBTB20-deficient plasma cells expressed reduced levels of MCL1 relative to wild-type controls, and transgenic expression of BCL2 increased serum antibody titers. These data indicate a role for ZBTB20 in promoting survival in plasma cells. Strikingly, adjuvants that activate TLR2 and TLR4 restored long-term antibody production in ZBTB20-deficient chimeras through the induction of compensatory survival programs in plasma cells. Thus, distinct lifespans are imprinted in plasma cells as they are formed, depending on the primary activation conditions. The durability of vaccines may accordingly be improved through the selection of appropriate adjuvants

    Keck Planet Finder: design updates

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    The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer in development at the UC Berkeley Space Sciences Laboratory for the W.M. Keck Observatory. KPF is designed to characterize exoplanets via Doppler spectroscopy with a goal of a single measurement precision of 0.3 m s-1 or better, however its resolution and stability will enable a wide variety of astrophysical pursuits. Here we provide post-preliminary design review design updates for several subsystems, including: the main spectrometer, the fabrication of the Zerodur optical bench; the data reduction pipeline; fiber agitator; fiber cable design; fiber scrambler; VPH testing results and the exposure meter

    Keck Planet Finder: design updates

    Get PDF
    The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer in development at the UC Berkeley Space Sciences Laboratory for the W.M. Keck Observatory. KPF is designed to characterize exoplanets via Doppler spectroscopy with a goal of a single measurement precision of 0.3 m s-1 or better, however its resolution and stability will enable a wide variety of astrophysical pursuits. Here we provide post-preliminary design review design updates for several subsystems, including: the main spectrometer, the fabrication of the Zerodur optical bench; the data reduction pipeline; fiber agitator; fiber cable design; fiber scrambler; VPH testing results and the exposure meter
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