194 research outputs found
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My artwork is about the impact of the digital revolution on every aspect of life, such as relationships, war, and self image. I explore this in the creation of sculptures that represent abstracted globes or video game worlds, digital animations concerning the virtual and simulated, and prints as allegories for embodied post-human experience. The visual themes of my work are bitmapped patterns, early computer graphics, and twenty-sided dice
DNA Repair Excision Nuclease Attacks Undamaged DNA: A POTENTIAL SOURCE OF SPONTANEOUS MUTATIONS
Nucleotide excision repair is a general repair system that eliminates many dissimilar lesions from DNA. In an effort to understand substrate determinants of this repair system, we tested DNAs with minor backbone modifications using the ultrasensitive excision assay. We found that a phosphorothioate and a methylphosphonate were excised with low efficiency. Surprisingly, we also found that fragments of 23-28 nucleotides and of 12-13 nucleotides characteristic of human and Escherichia coli excision repair, respectively, were removed from undamaged DNA at a significant rate. Considering the relative abundance of undamaged DNA in comparison to damaged DNA in the course of the life of an organism, we conclude that, in general, excision from and resynthesis of undamaged DNA may exceed the excision and resynthesis caused by DNA damage. As resynthesis is invariably associated with mutations, we propose that gratuitous repair may be an important source of spontaneous mutations
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A smart control system for electric vehicle batteries
A smart control system for electric vehicle (EV) batteries was designed and its performance was evaluated. The hardware for the system was based on the Motorola MC68HC11ENB micro controller. A zinc bromide (Zn/Br{sub 2}) battery was chosen since it is a good candidate as an EV battery and has a large number of user variable parameters that affect its performance. The flexibility of the system arises from the fact that the system can be programmed to do a wide variety of jobs. The use of real time interrupts and other features makes the system safe for use along with the battery systems. Test data indicates that real time control of the different parameters can increase the performance of the battery by 15%. In addition to optimizing the performance of the battery the control system incorporates essential safety features
An Item Response Curves Analysis of the Force Concept Inventory
Several years ago, we introduced the idea of item response curves (IRC), a simplistic form of item response theory (IRT), to the physics education research community as a way to examine item performance on diagnostic instruments such as the Force Concept Inventory (FCI). We noted that a full-blown analysis using IRT would be a next logical step, which several authors have since taken. In this paper, we show that our simple approach not only yields similar conclusions in the analysis of the performance of items on the FCI to the more sophisticated and complex IRT analyses but also permits additional insights by characterizing both the correct and incorrect answer choices. Our IRC approach can be applied to a variety of multiple-choice assessments but, as applied to a carefully designed instrument such as the FCI, allows us to probe student understanding as a function of ability level through an examination of each answer choice. We imagine that physics teachers could use IRC analysis to identify prominent misconceptions and tailor their instruction to combat those misconceptions, fulfilling the FCI authors\u27 original intentions for its use. Furthermore, the IRC analysis can assist test designers to improve their assessments by identifying nonfunctioning distractors that can be replaced with distractors attractive to students at various ability levels
Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants.
Dietary intervention with extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG (EHCF+LGG) accelerates tolerance acquisition in infants with cow's milk allergy (CMA). We examined whether this effect is attributable, at least in part, to an influence on the gut microbiota. Fecal samples from healthy controls (n=20) and from CMA infants (n=19) before and after treatment with EHCF with (n=12) and without (n=7) supplementation with LGG were compared by 16S rRNA-based operational taxonomic unit clustering and oligotyping. Differential feature selection and generalized linear model fitting revealed that the CMA infants have a diverse gut microbial community structure dominated by Lachnospiraceae (20.5±9.7%) and Ruminococcaceae (16.2±9.1%). Blautia, Roseburia and Coprococcus were significantly enriched following treatment with EHCF and LGG, but only one genus, Oscillospira, was significantly different between infants that became tolerant and those that remained allergic. However, most tolerant infants showed a significant increase in fecal butyrate levels, and those taxa that were significantly enriched in these samples, Blautia and Roseburia, exhibited specific strain-level demarcations between tolerant and allergic infants. Our data suggest that EHCF+LGG promotes tolerance in infants with CMA, in part, by influencing the strain-level bacterial community structure of the infant gut
The Impacts of Reduced Access to Abortion and Family Planning Services: Evidence from Texas
Between 2011 and 2014, Texas enacted three pieces of legislation that significantly reduced funding for family planning services and increased restrictions on abortion clinic operations. Together this legislation creates cross-county variation in access to abortion and family planning services, which we leverage to understand the impact of family planning and abortion clinic access on abortions, births, and contraceptive purchases. In-state abortions fell 20% and births rose 3% in counties that no longer had an abortion provider within 50 miles. Births increased 1% and contraceptive purchases rose 8% in counties without a publicly-funded family planning clinic within 25 miles
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