Showing 2081 - 2090 of 5708 Items
Date: 2020-02-11
Creator: Elizabeth A. Hoge, Hannah E. Reese, Isabelle A. Oliva, Caroline D. Gabriel, Brittany M., Guidos, Eric Bui, Naomi M. Simon, Mary Ann Dutton
Access: Open access
- Although mindfulness-based interventions (MBIs) have garnered empirical support for a wide range of psychological conditions, the psychological processes that mediate the relationship between MBIs and subsequent symptomatic improvement are less well-understood. In the present study we sought to examine, for the first time, the relationship between mindfulness, negative interpretation bias as measured by the homophone task, and anxiety among adults with Generalized Anxiety Disorder (GAD). Forty-two individuals with GAD completed measures of mindfulness, interpretation bias, and anxiety before and after treatment with Mindfulness-based Stress Reduction (MBSR). Contrary to prior research, we did not find evidence of an indirect relationship between baseline levels of mindfulness and anxiety via negative interpretation bias. MBSR did result in significant reductions in negative interpretation bias from baseline to post-treatment; however, we did not find evidence of an indirect relationship between changes in mindfulness and changes in anxiety via changes in interpretation bias. Taken together, these results provide minimal support for the hypothesized relationship between mindfulness, negative interpretation bias, and anxiety among adults with GAD. Limitations and specific suggestions for further inquiry are discussed.
Date: 2005-01-01
Creator: Anja Forche, Georgiana May, P. T. Magee
Access: Open access
- Candida albicans is a diploid yeast with a predominantly clonal mode of reproduction, and no complete sexual cycle is known. As a commensal organism, it inhabits a variety of niches in humans. It becomes an opportunistic pathogen in immunocompromised patients and can cause both superficial and disseminated infections. It has been demonstrated that genome rearrangement and genetic variation in isolates of C. albicans are quite common. One possible mechanism for generating genome-level variation among individuals of this primarily clonal fungus is mutation and mitotic recombination leading to loss of heterozygosity (LOH). Taking advantage of a recently published genome-wide single-nucleotide polymorphism (SNP) map (A. Forche, P. T. Magee, B. B. Magee, and G. May, Eukaryot. Cell 3:705-714, 2004), an SNP microarray was developed for 23 SNP loci residing on chromosomes 5, 6, and 7. It was used to examine 21 strains previously shown to have undergone mitotic recombination at the GAL1 locus on chromosome 1 during infection in mice. In addition, karyotypes and morphological properties of these strains were evaluated. Our results show that during in vivo passaging, LOH events occur at observable frequencies, that such mitotic recombination events occur independently in different loci across the genome, and that changes in karyotypes and alterations of phenotypic characteristics can be observed alone, in combination, or together with LOH.
Date: 2010-06-01
Creator: Erika Nyhus, Tim Curran
Access: Open access
- The primary aim of this review is to examine evidence for a functional role of gamma and theta oscillations in human episodic memory. It is proposed here that gamma and theta oscillations allow for the transient interaction between cortical structures and the hippocampus for the encoding and retrieval of episodic memories as described by the hippocampal memory indexing theory (Teyler and DiScenna, 1986). Gamma rhythms can act in the cortex to bind perceptual features and in the hippocampus to bind the rich perceptual and contextual information from diverse brain regions into episodic representations. Theta oscillations act to temporally order these individual episodic memory representations. Through feedback projections from the hippocampus to the cortex these gamma and theta patterns could cause the reinstatement of the entire episodic memory representation in the cortex. In addition, theta oscillations could allow for top-down control from the frontal cortex to the hippocampus modulating the encoding and retrieval of episodic memories. © 2009.
Date: 2000-05-01
Creator: Michael M. Franz
Access: Open access
- Interest groups now play a prominent role in the air war. Their collective investment in election campaigns has skyrocketed in the aftermath of Citizens United. Yet questions remain about whether interest group advertising affects the content of the specific issues being discussed. Do groups enter campaigns and engage voters on the same issues as their candidate allies? Or does the presence of more advertisers introduce competitive issue streams? This paper examines ad buys in Senate elections between 2008 and 2014 and the presidential elections of 2008 and 2012. A primary goal of the paper is to uncover the effect of high and low levels of "issue convergence" on election outcomes. Strategists often express concern that too many voices on behalf of a candidate can weaken the impact of ads. One might expect that as convergence between a candidate and his or her allies goes up (meaning the issue content of the ad buys overlaps across advertisers), the impact of ads on votes will increase. Ad effects should be weaker when a candidate's ads discuss different issues from allied groups and party committees. The results, however, suggest that high rates of issue convergence are only weakly related to election outcomes (and not always in consistent ways).
Date: 2021-01-01
Creator: Emily M. Peterman, Michael J. Jercinovic, Rachel J. Beane, Cameron B. de Wet
Access: Open access
- Cathodoluminescence (CL) images of kyanite reveal several internal textures, including sector zoning, oscillatory zoning, and cross-cutting relationships among different domains. Many textures observed in kyanite correspond to discrete events, thereby connecting kyanite textures to the pressure–temperature (P–T) history of the rock. To evaluate the record of metamorphism preserved by kyanite, metapelites were selected from three different orogens that reflect P–T conditions ranging from amphibolite to ultrahigh-pressure (UHP) facies. Cross-correlation of variations in CL intensity, chemistry, and crystal orientation within kyanite indicate the following findings. First, the preservation of original growth zones in kyanite from poly-metamorphic rocks demonstrates that growth zoning in kyanite persists through metamorphic events and is not erased by diffusion or complete recrystallization. In some samples, kyanite retains evidence of its reaction history during growth. Second, measured changes in absolute crystallographic orientation do not correspond with changes in CL intensity in any of the measured samples, including kyanite twins. Third, both kink banding and undulatory extinction are present across all samples, consistent with rotation about in the (100)[001] slip system. Kyanite from (U)HP samples exhibits higher amplitude undulations than kyanite from lower-grade lithologies, suggesting that crystallographic orientation data may provide complementary insight about deformation along the P–T path. Fourth, specific CL and trace element signatures in kyanite can be correlated with discrete metamorphic histories; yet, CL intensity and colour are affected by multiple elements, not a single controlling element. In sum, multiple generations of kyanite can be identified by careful cross-correlation of CL and geochemical data, and when combined with crystal orientation data, kyanite provides a robust record of a rock's P–T evolution.
Date: 2018-07-01
Creator: Danielle H. Dube
Access: Open access
- “Drug Discovery” is a 13-week lecture and laboratory-based course that was developed to introduce non-science majors to foundational chemistry and biochemistry concepts as they relate to the unifying theme of drug discovery. The first part of this course strives to build students' understanding of molecules, their properties, the differences that enable them to be separated from one another, and their abilities to bind to biological receptors and elicit physiological effects. After building students' molecular worldview, the course then focuses on four classes of drugs: antimicrobials, drugs that affect the mind, steroid-based drugs, and anti-cancer drugs. During each of these modules, an emphasis is placed on how understanding the basis of disease and molecular-level interactions empowers us to identify novel medicinal compounds. Periodic in class discussions based on articles pertinent to class topics ranging from the spread of antibiotic resistance, to the molecular basis of addiction, to rational drug design, are held to enable students to relate course material to pressing problems of national and daily concern. In addition to class time, weekly inquiry-based laboratories allow students to critically analyze data related to course concepts, and later in the semester give students an opportunity to design and implement their own experiments to screen for antimicrobial activity. This course provides students with an understanding of the importance of chemistry and biochemistry to human health while emphasizing the process, strategies, and challenges related to drug discovery. © 2018 by The International Union of Biochemistry and Molecular Biology, 46:327–335, 2018.
Date: 2015-03-01
Creator: Aidan W. Short, David B. Carlon
Access: Open access
- A new wave of green crabs Carcinus maenus is sweeping through the Gulf of Maine (GOM). While first reports of green crabs in the GOM date from the early 1900s, populations in southern GOM have exploded in the last five years. In the Casco Bay region, this unusually high abundance is associated with poor commercial shellfish landings and the decline of eel grass habitat (Zostera marina). To determine the mechanistic roles green crabs play in direct and indirect ecological interactions, it is important to understand diet breadth, and how feeding preferences change in response to ecological context. Since green crabs are omnivorous, traditional approaches to diet analysis via hard parts suffer from substantial bias. We are using DNA barcoding and next generation sequencing (NGS) to analyze green crab diets from a longitudinal sampling design in Casco Bay. In addition to a temporal dimension, our design includes two habitats: clam flats and eel grass beds. We have now sampled ~ 1000 crabs and have processed 460 individual stomachs from a range of sizes and both sexes. Here we will present: our sampling design, our NGS pipeline, and preliminary analysis from a lobster-specific (Homarus americanus) probe. Presenting author status: Undergraduate Preferred presentation type: Poster Preferred topics: 3. Biological invasions; 18. Molecular ecology Benthic Ecology Meeting, 2015 Quebec City, Canada Aidan Short was an undergraduate student at Bowdoin College when this research was conducted.
Date: 2016-04-15
Creator: Michèle LaVigne, Andréa G. Grottoli, James E. Palardy, Robert M. Sherrell
Access: Open access
- The coral skeleton barium to calcium ratio (Ba/Ca ), a proxy for seawater barium concentrations (Ba ), has been interpreted as a tracer of upwelling based on the characteristic "nutrient like" depth profile of Ba . However, in some tropical regions, such as the Gulf of Panamá, substantial influence of terrestrial runoff inputs and differences between the vertical distribution of Ba and that of the major nutrients (nitrate and phosphate) in the upper water column can complicate the interpretation of Ba/Ca as an upwelled nutrient proxy. In the Gulf of Panamá, contemporaneous Ba/Ca records from multiple colonies of Porites lobata, Pavona gigantea, and Pavona clavus corals record a nearly twofold change in surface water Ba as a 20-70% increase in skeletal Ba/Ca with excellent correlation among Ba/Ca records from co-located colonies (r = 0.86-0.99). These results provide, for the first time, an absolute calibration of the coral Ba proxy with a contemporaneous Ba record. Compiling the Ba/Ca records from three co-located colonies of each species into taxon-specific composite regressions reveals strong statistically significant correlations with the Ba time-series record (p < 0.001). Differences among taxa in regression slope, y-intercept, and average distribution coefficient, as well as a demonstration of the application of the P. clavus calibration to a previously published Ba/Ca record, emphasize the necessity of using taxon-specific calibrations to reconstruct changes in Ba with accuracy. These results support the application of Ba/Ca to reconstruct past changes in absolute Ba concentrations, adding an important tool to the collection of geochemical proxies for reconstructing surface ocean biogeochemical processes in the past. coral SW SW SW coral coral SW SW coral SW coral SW coral SW
Date: 1960-01-01
Creator: Kevin Herbert
Access: Open access
- Bulletin / Bowdoin College ; no. 335