Design and testing of the LITE Variable Field Stop mechanism

The Variable Field Stop (VFS) is a rotary mechanism that reliably positions any of four aperture plates in the optical path of a spaceflight experiment, limiting the amount of light reaching the detectors. This paper discusses the design, operation, and testing of the VFS

Design Effects in the Transition to Web-Based Surveys

Innovation within survey modes should always be mitigated by concerns about survey quality and in particular sampling, coverage, nonresponse, and measurement error. This is as true today with the development of web surveying as it was in the 1970s when telephone surveying was being developed. This paper focuses on measurement error in web surveys. Although Internet technology provides significant opportunities for innovation in survey design, systematic research has yet to be conducted on how most of the possible innovations might affect measurement error, leaving many survey designers “out in the cold.” This paper summarizes recent research to provide an overview of how choosing the web mode affects the asking and answering of questions. It starts with examples of how question formats used in other survey modes perform differently in the web mode. It then provides examples of how the visual design of web surveys can influence answers in unexpected ways and how researchers can strategically use visual design to get respondents to provide their answers in a desired format. Finally, the paper concludes with suggested guidelines for web survey design

The Case of the Missing Music: An Outreach Activity Sparks Interest in Science and Density

From Scooby Doo and Nancy Drew to the countless other detectives that fill children’s bookshelves and television programs, it is clear that children are fascinated with solving crimes. As a result, a chemistry professor who performs outreach activities at local elementary schools exploited this interest in mysteries as a method to spark curiosity in science. This was accomplished through the development of an outreach activity in which students solve a mystery using density and fingerprint analysis

The Design and Synthesis of Novel Goniothalamin Analogues

Every two minues a woman in the United States is diagnosed with breast cancer. In recent years, one method to identify potential chemotherapeutic agents has been the mass screening of natural products of cytotoxicity. One compound discovered in this manner was goniothalamin. Gonothalamin was isolated from the dried stem bark of the plant Goniothalamus sesuipedalis and exhibits cell specific anticancer activity against breast cancer. Goniothalamin has been extensively studies and a large number of synthetic analogues have been prepared in an attempt to determine the structural features necessary for bioactivity. These studies have focused primarily on the manipulation of goniothalmin\u27s styryl substituent. The focus of this research is on the lactone core of goniothalamin. Analogues have been prepared that replace the lactone ring with lactam. It is anticipated that alteration of the lactam nitrogen substituent will potentially lead to analogues with better bioavailability and reactivity than the natural product

Autologous Peripheral Blood Mononuclear Cell Recognition of Autologous Proliferating Tumor Cells in the Context of a Patient-Specific Vaccine Trial

Metastatic melanoma patients who were treated with patient-specific vaccines consisting of dendritic cells loaded with autologous tumor cells had a 5-year survival of over 50%. Enzyme-linked immunospot (ELISPOT) has been used to detect antigen reactive T cells as a means of determining immune response. We wished to determine whether IFN-gamma secretion in an ELISPOT assay was prognostic or predictive for survival following treatment. Peripheral blood mononuclear cells (PBMCs) collected at weeks 0 and 4 were evaluated by ELISPOT assay for response to autologous tumor cells. Overall, there was slight increase in the number of tumor reactive lymphocytes from week 0 to week 4. Using >5 spots/100 K PBMC as the cutoff, a log-rank analysis revealed only a slight statistical significance in overall survival for patients who lacked tumor reactive PBMCs at week 4. The sensitivity of ELISPOT in the context of patient-specific cellular vaccines is unclear

An Entomopathogenic Nematode by Any Other Name

Among the diversity of insect-parasitic nematodes, entomopathogenic nematodes (EPNs) are distinct, cooperating with insect-pathogenic bacteria to kill insect hosts. EPNs have adapted specific mechanisms to associate with and transmit bacteria to insect hosts. New discoveries have expanded this guild of nematodes and refine our understanding of the nature and evolution of insect–nematode associations. Here, we clarify the meaning of “entomopathogenic” in nematology and argue that EPNs must rapidly kill their hosts with the aid of bacterial partners and must pass on the associated bacteria to future generations

Temperature-dependent changes in the host-seeking behaviors of parasitic nematodes

Olfactory plasticity occurs in individual infective juveniles (IJs), is not affected by cultivation density, and occurs in multiple strains of Steinernema carpocapsae. A. Temperature-induced changes in sensory valence occur in individual IJs. 25 °C IJs that were repelled by 2-propanone on day 0 were collected and cultured at either 15 °C or 25 °C for 2 weeks, and then re-tested on day 14 using a modified scoring method (left). The IJs that were temperature-swapped from 25 °C to 15 °C showed opposite olfactory preferences compared to those maintained at 25 °C. *** P < 0.001, unpaired t-test; n = 6 trials for each condition. Red bar = 1 cm. B. Cultivation density does not affect temperature-induced sensory valence changes; 25 °C day 0 Ste. carpocapsae IJs were collected and stored at 15 °C at low density (1 IJ/μL), medium density (6 IJ/μL), or high density (25 IJ/μL) and tested for their response to 2-propanone and 1-hexanol after 2 weeks of storage. No significant effects of cultivation density (F 2,62 = 0.2586, P = 0.7730) or interaction (F 2,62 = 1.912, P = 0.1565) were observed in a two-way ANOVA; n = 8–18 trials for each condition. C. Multiple strains of Ste. carpocapsae exhibit temperature-dependent olfactory plasticity. In addition to the standard All strain, the DD136 and Sal strains [101] also exhibited temperature-induced sensory valence changes. A comparison of day 0 IJs that were cultured at 25 °C, day 14 IJs that were temperature-swapped from 25 °C to 15 °C on day 0, and day 14 IJs that were cultured at 25 °C revealed both temperature- and age-dependent changes in olfactory responses. ** P < 0.01; *** P < 0.001 relative to 25 °C day 0 IJs, two-way ANOVA with Dunnett’s post-test; n = 6–16 trials for each condition. For all graphs, error bars represent standard error of the mean (SEM). Mean, n, and SEM values for each assay are listed in Additional file 7: Dataset S1. (PDF 529 kb

Competency-Based Education: A Framework for a More Efficient and Safer Aviation Industry

Aircraft design and reliability as well as pilots’ education and training have steadily and significantly improved in the last 20 years. Nevertheless, high-profile accidents still occur, even when the aircraft and related systems are operating adequately. Controlled flight into terrain, runway incursion accidents, and loss of control in flight are examples of mishaps in which inadequate decision-making, poor leadership, and ineffective communication are frequently cited as contributing factors. Conversely, the investigation of accidents (e.g., US Airways Flight 1549, in the U.S. on Jan. 15, 2009) and serious incidents (e.g., TAM Linhas Aereas Flight 3756 in Brazil on June 17, 2011) have shown that flight crews must be flexible and adaptable, think outside the box, and communicate effectively to cope with situations well beyond their individual expertise

The Role of Email Communications in Determining Response Rates and Mode of Participation in a Mixed-mode Design

This article is concerned with the extent to which the propensity to participate in a web-face-to-face sequential mixed-mode survey is influenced by the ability to communicate with sample members by email in addition to mail. Researchers may be able to collect email addresses for sample members and to use them subsequently to send survey invitations and reminders. However, there is little evidence regarding the value of doing so. This makes it difficult to decide what efforts should be made to collect such information and how to subsequently use it efficiently. Using evidence from a randomized experiment within a large mixed-mode national survey, we find that using a respondent-supplied email address to send additional survey invites and reminders does not affect survey response rate but is associated with an increased proportion of responses by web rather than face to face and, hence, lower survey costs