Improvement of three dimensional acoustic field estimation using tomographic reconstructions of the ocean

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1988In order to determine the efficacy of tomographic reconstructions of the ocean sound speed structure in improving acoustic field predictions for source localization, a 150 km by 350 km volume of ocean 3000 meters deep was synthetically modeled to be similar to the Gulf Stream system, including an eddy and a front. The features were Gaussian, with the eddy's maximum sound speed perturbation being 10ms-1 and the front's maximum perturbation 15ms-1. Two vertical slices through this system were inverted in a synthetic tomography experiment using linear optimal estimation theory. Inversions were also performed using XSV and satellite sea surface temperature data. Gaussian fits to the reconstructed features were constructed for use with a three dimensional raytrace program (HARPO). Three dimensional rays were propagated both through the reconstructions and the original model. Travel time versus intensity (transmission loss) for the eigenrays was used as a basis for intercomparison. Tomographic results showed good reconstruction for a first iteration of the inversion, but inadequate vertical resolution. Iterations and the use of more refractive eigenrays are needed for improvement of the reconstruction, especially for the front. Reconstructed results for the acoustic field should improve conventional beamforming, but are probably inadequate for matched field processing

The Effect of Repeated Opioid Dosing on the Gut Microbiome

Opioids are prescribed to millions of people each year, especially to help patients cope with chronic pain, something from which more than a fifth of U.S. adults suffer (CDC). Unfortunately, opioid use and abuse has become a national emergency as the number of opioid prescriptions, opioid misuse, and opioid-related drug overdoses and death have drastically increased in the last twenty years (HHS). Because of the emergent state surrounding opioid use and misuse, the effects of opioids on all aspects of the human body has been an increasingly large focus of research scientists. This study focuses on the possible effect of repeated opioid administration on the gut microbiome. The human gut microbiome has also been a significant focus for researchers recently as more evidence is unveiling the effects of the gut microbiome on several organs of the body, especially the brain (Galland). It remains unclear the mechanism by which opioids affect humans beyond pain management, particularly cognitive function, mood and behavior. Given the similarities of side effects between gut microbial dysbiosis and chronic opioid use, including decreased gut motility, increased inflammation, altered cognitive function, and behavioral changes, it is possible that some of the effects of opioids on the brain’s cognitive functions are mediated through microbial effectors due to alterations in gut microbial composition upon prolonged usage of opioids. Therefore, our lab took special interest in the possible link between opioids, the gut, and the brain. It was our aim to provide evidence that repeated Buprenorphine, a partial µ-opioid receptor agonist, dosing alters gut microbial composition. By first isolating DNA from non-human primate fecal samples and analyzing DNA quality we were able to prepare DNA libraries and perform DNA Illumina Next-Generation shotgun sequencing. At the phylum level we observed a fairly common trend in treated subjects of increased Firmicutes during dosing followed by a decrease toward baseline after one week post-dosing. We also observed increases and decreases in the sub-dominant phylum in treated subjects at two weeks of dosing followed by a respective decrease or increase toward baseline after one week post-dosing; however, these trends were less consistent. At the genus level we were unable to observe any trends as a result of opioid administration. Upon performing a non-parametric Wilcoxin Signed-Rank Test, it was determined that there was no significant differential abundance between time points in treated subjects. Quantitative PCR was also performed to validate our sequencing results, but considering the lack of trends we observed, it proved to be difficult to validate anything. In the end, we were unable to provide significant evidence for our hypothesis. The gut microbiome varies so greatly among and within individuals that finding a significant and consistent alteration in bacterial abundance across all treated subjects proved nearly impossible. What we were able to take away from the study was the observation of some alteration in the microbiome which will need to be studied further by incorporating predicted experimental improvements gleaned from our pilot studies. Despite our results, it is still our hypothesis that opioids affect the microbiome and we encourage future researchers to use our findings as a guide for their experimental design

A Meta-Analysis of Self-Regulated Learning Interventions and Learning Outcomes in Higher Education E-Learning Environments

Through a systematic review of the literature, 36 empirical studies regarding self-regulated learning (SRL) interventions and learning outcomes in higher education e-learning environments were identified and meta-analyzed using15 years of data. Frequently studied interventions included providing SRL scaffolding, SRL training, or SRL training and scaffolding either as a precursor or as part of the learning environment or both. Scaffolding interventions were embedded as part of the learning environment and designed to guide learners to perform cognitive and metacognitive strategies such as task analysis, goal setting, and reflection during a learning activity. Training interventions, by contrast, involved instruction in the use of SRL strategies prior to beginning a learning activity, course or program. In some studies, both training and scaffolding SRL interventions were implemented. Information about the types of SRLinterventions including the means of measuring learning outcomes (more or less complex), instructional design characteristics and learning outcomes data for calculating effect sizes were extracted for the purposes of conducting this meta-analysis

Plasmodium falciparum:Rosettes do not protect merozoites from invasion-inhibitory antibodies

Rosetting is a parasite adhesion phenotype associated with severe malaria in African children. Why parasites form rosettes is unknown, although enhanced invasion or immune evasion have been suggested as possible functions. Previous work showed that rosetting does not enhance parasite invasion under standard in vitro conditions. We hypothesised that rosetting might promote invasion in the presence of host invasion-inhibitory antibodies, by allowing merozoites direct entry into the erythrocytes in the rosette and so minimising exposure to plasma antibodies. We therefore investigated whether rosetting influences invasion in the presence of invasion-inhibitory antibodies to MSP-1. We found no difference in invasion rates between isogenic rosetting and non-rosetting lines from two parasite strains, R29 and TM284, in the presence of MSP-1 antibodies (P=0.62 and P=0.63, Student's t test, TM284 and R29, respectively). These results do not support the hypothesis that rosettes protect merozoites from inhibitory antibodies during invasion. The biological function of rosetting remains unknown

A comparison of preschool children's discussions with parents during picture book and chapter book reading

Discussions that occur during book reading between parents and preschool children relate to children’s language development, especially discussions during picture books that include extended discourse, a form of abstract language. While a recent report shows increased chapter book reading among families with preschool children, it is unknown whether chapter books also facilitate these types of conversations. Further, the substantial variation in preschoolers’ language ability raises the question of whether chapter book reading may be beneficial for all children of this age. The current study examined the discussions between five-year-old children (N = 33) and their parents while reading both a picture book and the first chapter of a chapter book. Findings are discussed in terms of the variation observed in the amount and types of discussion, how chapter book discussions compare to picture book discussions, and finally, how children’s narrative skill can serve as an indicator of children’s ability to participate in discussions, especially during chapter book reading

Parks in the Hertfordshire landscape: the wider implications

The history of the Hertfordshire landscape and, in particular, the history of its deer parks has been a primary interest and focus of my research for the past thirty years, resulting in a significant number and range of publications. This commentary sets the findings of that research into the wider historiographical framework of parks scholarship, demonstrating its contribution to our growing understanding of an important aspect of landscape history. Extensive archival research combined with a multi-disciplinary approach have resulted in the most comprehensive analysis of the deer parks of any county between the eleventh and seventeenth centuries, providing new, empirically based evidence of their continuing significance and purpose over many centuries. The Hertfordshire data provides new insights into the relationship between the distribution of early parks and woodland, the continued importance of parks throughout the Middle Ages and into the Early Modern period, the variations in the extent of imparkment over time, both in terms of numbers and acreage, the social status of the park owners, the influence of London and of the hunting monarchs. In addition to providing arenas for elite hunting, parks became increasingly important as ornamental landscapes around major houses and the sixteenth century witnesses the dawning of landscape design in Hertfordshire. Parks provided the settings for some historically important gardens and surviving field archaeology for several of these – from Tudor times to the eighteenth century – has been recorded and published. Further aspects of parkland management have also been explored, including the prevalence of rabbit warrens and the management of parkland trees

08051 Abstracts Collection -- Theory of Evolutionary Algorithms

From Jan. 27, 2008 to Feb. 1, 2008, the Dagstuhl Seminar 08051 ``Theory of Evolutionary Algorithms\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Father Input and Child Vocabulary Development: The Importance of Wh Questions and Clarification Requests

Individual differences in children’s language skills have been shown to stem in part from variations in the quantity and quality of parent speech input. However, most research focuses on mothers’ input whereas less is known about the effects of variability in father input. In this article, we review the relation between parent input and child language development with a focus on low-income families, and review general findings about similarities and differences in mother and father speech. Within this review, we highlight conversation-eliciting speech, such as wh questions and clarification requests, which occur, on average, more frequently in father input than mother input. Conversation-eliciting speech is challenging for 2-year-old children and has been shown in research with mothers to relate to child vocabulary development.We then report a study examining whether fathers’ use of conversation-eliciting speech relates to children’s developing vocabulary skills at 24 months of age within a sample of lowincome African American families. Understanding that speech input varies among fathers, and specific strengths that fathers bring to interactions with their young children can help speech-language pathologists develop and implement more effective interventions

Peer observation of teaching: a decoupled process

This article details the findings of research into the academic teaching staff experience of peer observation of their teaching practice. Peer observation is commonly used as a tool to enhance a teacher's continuing professional development. Research participants acknowledged its ability to help develop their teaching practice, but they also reported that it could operate superficially as a tick box exercise, that its outcomes were frequently decoupled from formal staff development processes, and that its purpose and usefulness therefore seemed unclear. This article argues that the presence of decoupling reinforces the need to account for structural factors that can interact with peer observation of teaching to ensure it is a meaningful exercise for all teaching staff. It concludes that the published academic literature is perhaps guilty of overplaying the role of personal choice and individual tutor characteristics when addressing the complex issue that is staff disengagement with peer observation of teaching. © The Author(s) 2011

Diversity of large woody lignophytes preceding the extinction of Archaeopteris: new data from the middle Tournaisian of Thuringia (Germany)

International audienceAnatomically preserved axes representing three lignophyte species occur in the middle Tournaisian deposit of Kahlleite in Thuringia. One is characterized by a small oval eustele, short uniseriate rays, and alternate distichous phyllotaxy. It is assigned to the progymnosperm genus Protopitys. The two others share a eustelic primary vascular system comprising a parenchymatous pith and numerous xylem strands in a peripheral position. The secondary xylem comprises rays that are mostly uniseriate and rarely exceed 20 cells in height. One is referred to as Eristophyton sp.; the second, characterized by ray cells showing a wide range of sizes and shapes is assigned to Aporoxylon primigenium. These records extend the stratigraphical range of Protopitys and Eristophyton down to the middle Tournaisian and confirm their great longevity through most of the Mississippian. They suggest that the diversity of putative arborescent lignophytes co-occurring with Archaeopteris around the D/C boundary but surviving successfully above this limit has been underestimated