439 research outputs found

    Progress towards Bose-Einstein condensation on an atom chip as a functional testbed for experiments aboard the orbital NASA Cold Atom Laboratory

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    Since their initial production in 1995, the study of Bose-Einstein Condensates (BECs) has offered exciting new insights into many fields including quantum mechanics and solid state physics. Atom chips, non-conducting surfaces with conducting lithographic traces printed on them, have proven successful in generating lower power magnetic traps for the formation of BECs. The combination of their lower power consumption, small form factor, and dense traps makes atom chips a promising way to face a ubiquitous challenge in the study of BECs: the effect of the earth’s gravitational field. To avoid these effects the NASA Cold Atom Laboratory aims to create BECs aboard the International Space Station (ISS) using an atom chip. This thesis presents the development of a similar atom chip based BEC experiment at Bates College, which will serve as a functional testbed for future research aboard the ISS. Both a theoretical background and a description of the experimental process by which a BEC is formed on an atom chip are provided. This process is primarily driven by laser cooling and magnetic trapping techniques. A 2D+ Magneto-Optical Trap (MOT), loaded from vapor pressure, is used as a slowed source of 87Rb in order to create a 3D MOT. We present measurements of the performance of both MOTs, and outline a path forward to condensation on the chip-based magnetic trap through use of radiofrequency evaporative cooling

    Chapter 12: Public Housing

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    Investigating Moderation in the Prospective Relationship of Marijuana Use to Subsequent Illicit Substance Use: Evidence from Add Health

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    While socially normalized substances (e.g., marijuana) may increase the probability of subsequent progression to more harmful illicit substances, previous empirical research on the topic has yielded inconsistent results. Few studies have prospectively examined whether age of first documented current marijuana use is related to later harmful illicit substance use over multiple life course stages, or considered potential moderation of the process by age of first documented current marijuana use, gender, or race/ethnicity. To investigate this topic, data from five waves the National Longitudinal Study of Adolescent to Adult (N=20,774), spanning ages 12-42, were used to analyze the prospective association of current marijuana use at any of the five waves to current illicit substances in early middle adulthood (i.e., Wave 5), conditional on sociodemographic controls. Moderation in the effect of first documented current marijuana use on later illicit substance use was tested for three putative moderators, gender, race/ethnicity, and age of first reported current marijuana use, using interaction effects. Multiple imputation was used to address a modest amount of missing data. Results indicate that current marijuana use at any wave was strongly associated with documented current illicit substance use in early middle adulthood (OR=4.506, p

    Early Life Depression: Social Moderation of the Influences of Neurotransmitter Candidate Genes and Physical Attractiveness

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    Understanding the social determinants of depression has remained a primary concern in the mental health literature for decades. Investigation into the topic has been productive, yielding a number of robust empirical findings and organizing theoretical frameworks. Thus, social scientists have made substantial progress in elucidating how social factors including stressful events, social support and socio-economic status influence depression over the life course. However, it is also clear that there are considerable individual differences in the impact of social factors, with some individuals showing greater vulnerability than others. This fact suggests that much of the variance in depression is due to interactions between social factors and personal characteristics not typically examined in social science research. This dissertation elaborates this line of reasoning, investigating social moderation of the influence of five neurotransmitter candidate genes and physical attractiveness on depression using data from the National Longitudinal Study of Adolescent Health. In the first empirical chapter, the direct and interactive influences of candidate genes and various dimensions of social environmental risk on depression are examined. Using false discovery rate (FDR) methods to account for multiple testing, evidence suggests possible interactions between the MAOA VNTR promoter polymorphism, particularly the 2 repeat and 3.5/4 repeat variants, and social support among females. In the second empirical chapter, temporal variation in the influence of neurotransmitter candidate genes across early life is examined. Again using FDR methods to account for multiple testing, results indicate temporal variation in the effects of the DRD4 dopamine receptor gene (5 repeat variant) for the full sample, and the MAOA VNTR promoter polymorphism (3.5 repeat) among males. The final substantive chapter examines the depressogenic influence of another source of individual differences rarely considered by social scientists--physical attractiveness. Results indicate that attractiveness becomes increasingly influential on depression as individuals age through adolescence and young adulthood, and that less attractive individuals are more resilient to the effects of eventful stress than their more attractive counterparts. Overall, this research demonstrates that, in addition to their main effects on depression, social factors represent important moderators of the influence of genetic variation and physical attractiveness

    Improving Access to Quality Health Information in Rural Communities through Little Free Libraries

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    Objective: Little Free Libraries (LFLs) are neighborhood book-exchange boxes. Okeechobee County Public Library in Florida partnered with the University of Florida Health Science Center Libraries on a grant-funded project to add health education components to 30 new public library-sponsored LFLs built on rural county properties. The objective was to improve rural residents\u27 health literacy and awareness of NIH\u27s All of Us Research Program. Methods: The libraries collaborated to select and purchase 424 consumer health books in English and Spanish. Online consumer health materials were selected and printed. Laptops and Wi-Fi hotspots were also purchased, as the public library will collaborate with their county Health Department to conduct mobile health reference hours at the LFLs when possible. Health librarians conducted a one-day training for county health educators and public library employees on: health reference techniques; evaluating and using online health resources; health literacy; strategies for successful health tabling; and conveying the benefits of All of Us to patrons. The eHEALS eHealth Literacy Scale was administered before and after the training. Results: Nine LFLs have been installed in lower-income neighborhoods; all 30 will be completed by July 2021. To date, the most popular LFL location is at a sports complex with over 600 items circulated since April 2020. The most frequently restocked health resources are related to teaching children healthy habits. The eHEALS results demonstrated that the training day increased participants\u27 perceived ability to navigate health information online. Conclusions: Although not yet complete, this project has already improved rural residents\u27 awareness of and access to authoritative consumer health resources. Overall, the LFLs and the planned health reference sessions will contribute towards reducing health information disparities amongst underserved populations, as county residents are empowered to make effective use of information for health decision-making

    An Investigation Comparing the Efficacy of Topical Ocular Application of Tacrolimus and Cyclosporine in Dogs

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    The purpose of this paper was to determine the efficacy and safety of topical tacrolimus, compared to cyclosporine, for treating keratoconjunctivitis sicca (KCS) in dogs. This study was a two-phase, randomized, controlled, masked clinical trial. Phase 1 evaluated ophthalmic 0.03% tacrolimus in normal dogs. Ocular examinations were performed daily. Phase 2 evaluated the efficacy of tacrolimus in treating KCS. Half the dogs received 2% cyclosporine A; the others received 0.03% tacrolimus, both diluted in olive oil. Four ophthalmic examinations were done over 12 weeks. There was no significant difference between groups in phase I. In phase 2, there was no significant difference in Schirmer tear test I (STT) results between the two groups, and both groups had a significant increase in STT over time. Both drugs were effective in increasing the STT in dogs naĂŻve to lacrimostimulants. Tacrolimus was effective in increasing the STT in 4 dogs currently nonresponsive to cyclosporine

    Risk-stratified patients with resectable soft tissue sarcoma benefit from epirubicin-based adjuvant chemotherapy

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    As adjuvant chemotherapy (AC) for soft tissue sarcomas is controversial, we performed a retrospective analysis of patients seen at Washington University in St. Louis to evaluate whether it benefited our patient population. Patients were risk-assessed using the Memorial Sloan Kettering Predictive Nomogram (MSKPN). We defined high-risk patients by a MSKPN 4-year postoperative probability of sarcoma-specific death of ≥0.3 and investigated if they benefited from AC. Retrospective review was performed on patients seen between 15 February 1996 and 6 February 2010. A propensity score method in the logistic regression framework was used to model the likelihood of receiving AC. To make causal inference on the effect of AC on survival outcomes, a propensity score inverse probability of treatment weighting approach was applied to survival analysis. Overall, 135 high-grade patients were assessed, 33 were treated with Ifosfamide/Epirubicin (I/Epi) and 102 were non AC patients. The stratified MSKPN risk was not significantly associated with any survival endpoint in the whole cohort, but trended for overall survival (OS) when evaluated against non AC patients. After adjustment for MSKPN risk and other variables, patients not receiving chemotherapy had significantly worse OS, recurrent free survival, and disease-specific survival (DSS) with adjusted hazard ratios of 4.18 (95% CI: 2.22–7.90), 8.96 (95% CI: 3.85–20.83), and 5.42 (95% CI: 2.09–14.06), respectively. In retrospective analyses, risk-stratified patients with soft tissue sarcoma benefited from I/Epi-based AC. Randomized I/Epi versus I/Doxorubicin clinical trials may determine the optimal adjuvant treatment

    Deep-sea scleractinian coral age and depth distributions in the northwest Atlantic for the last 225,000 years

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    Author Posting. © University of Miami - Rosenstiel School of Marine and Atmospheric Science, 2007. This article is posted here by permission of University of Miami - Rosenstiel School of Marine and Atmospheric Science for personal use, not for redistribution. The definitive version was published in Bulletin of Marine Science 81 (2007): 371-391.Deep-sea corals have grown for over 200,000 yrs on the New England Seamounts in the northwest Atlantic, and this paper describes their distribution both with respect to depth and time. Many thousands of fossil scleractinian corals were collected on a series of cruises from 2003-2005; by contrast, live ones were scarce. On these seamounts, the depth distribution of fossil Desmophyllum dianthus (Esper, 1794) is markedly different to that of the colonial scleractinian corals, extending 750 m deeper in the water column to a distinct cut-off at 2500 m. This cut-off is likely to be controlled by the maximum depth of a notch-shaped feature in the seamount morphology. The ages of D. dianthus corals as determined by U-series measurements range from modern to older than 200,000 yrs. The age distribution is not constant over time, and most corals have ages from the last glacial period. Within the glacial period, increases in coral population density at Muir and Manning Sea-mounts coincided with times at which large-scale ocean circulation changes have been documented in the deep North Atlantic. Ocean circulation changes have an effect on coral distributions, but the cause of the link is not known.We gratefully acknowledge the support of The Comer Foundation for Abrupt Climate Change, The Henry Luce Foundation, The American Chemical Society Petroleum Research Fund, NSF Grant Numbers OCE-0096373 and OCE-0095331, and NOAA OE Grant Number A05OAR4601054
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