Reactive Quenching Of Od A (2)Σ(+) By H-2: Translational Energy Distributions For H- And D-Atom Product Channels

The H- and D-atom products from collisional quenching of OD A (2)Sigma(+) by H-2 are characterized through Doppler spectroscopy using two-photon (2 S-2 \u3c-\u3c- 1 S-2) laser-induced fluorescence. Partial deuteration enables separation of the channel forming H + HOD products, which accounts for 75% of reactive quenching events, from the D + H2O product channel. The Doppler profiles, along with those reported previously for other isotopic variants, are transformed into product translational energy distributions using a robust fitting procedure based on discrete velocity basis functions. The product translational energy distribution for the H- atom channel is strongly peaked at low energy (below 0.5 eV) with a long tail extending to the energetic limit. By contrast, the D-atom channel exhibits a small peak at low translational energy with a distinctive secondary peak at higher translational energy (approximately 1.8 eV) before falling off to higher energy. In both cases, most of the available energy flows into internal excitation of the water products. Similar distributions are obtained upon reanalysis of D- and H- atom Doppler profiles, respectively, from reactive quenching of OH A (2)Sigma(+) by D-2. The sum of the translational energy distributions for H- and D- atom channels is remarkably similar to that obtained for OH A (2)Sigma(+) + H-2, where the two channels cannot be distinguished from one another. The product translational energy distributions from reactive quenching are compared with those obtained from a previous experiment performed at higher collision energy, quasiclassical trajectory calculations of the post-quenching dynamics, and a statistical model. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3644763

Application of a Theory-Driven Approach to Detect Cognitively Disengaged Test-Taker Behavior

Bottom-up, data-driven response filtering methods that exclude unrealistically fast responses from calculating test scores have been successfully applied to improve test validity. We introduce a top-down, theory-driven method to detect cognitively disengaged behavior, compare it with a data-driven method using data from a nationally representative reading assessment, and discuss its potential and limitations

Source Expertise and Question Type Effects in Conversation-Based Assessment

Conversational discourse is a cognitive and social process influenced by both discourse content and pragmaticfactors, such as the participants’ prior knowledge; these factors may also affect how simulated conversations with virtual agentsunfold, with implications for design. This study explored effects of question content and perceived expertise of a virtual agenton students’ interactions with a conversation-based assessment (CBA) measuring science inquiry skills. Twenty-four middleschool students were randomly assigned to work with a High- or Low-Knowledge virtual peer to collect data and generateweather predictions. Students evaluated their own data relative to the peer’s; they could either ”Choose” which note to keep, orto ”Agree/Disagree” with the peer’s suggested choice of note. Students rated the peer as more expert in the High-Knowledgecondition, but peer expertise did not affect performance. However, the Agree/Disagree condition improved students’ accuracyin their note choice, and yielded marginally higher pre-post learning gains

RIP kinase 1-dependent endothelial necroptosis underlies systemic inflammatory response syndrome

Receptor interacting protein kinase 1 (RIPK1) has important kinase-dependent and kinase-independent scaffolding functions that activate or prevent apoptosis or necroptosis in a cell context-dependent manner. The kinase activity of RIPK1 mediates hypothermia and lethality in a mouse model of TNF-induced shock, reflecting the hyperinflammatory state of systemic inflammatory response syndrome (SIRS), where the proinflammatory cytokine storm has long been viewed as detrimental. Here, we demonstrate that cytokine and chemokine levels did not predict survival and, importantly, that kinase-inactive Ripk1D138N/D138N hematopoietic cells afforded little protection from TNF- or TNF/zVAD-induced shock in reconstituted mice. Unexpectedly, RIPK1 kinase-inactive mice transplanted with WT hematopoietic cells remained resistant to TNF-induced shock, revealing that a nonhematopoietic lineage mediated protection. TNF-treated Ripk1D138N/D138N mice exhibited no significant increases in intestinal or vascular permeability, nor did they activate the clotting cascade. We show that TNF administration damaged the liver vascular endothelium and induced phosphorylated mixed lineage kinase domain-like (phospho-MLKL) reactivity in endothelial cells isolated from TNF/zVAD-treated WT, but not Ripk1D138N/D138N, mice. These data reveal that the tissue damage present in this SIRS model is reflected, in part, by breaks in the vasculature due to endothelial cell necroptosis and thereby predict that RIPK1 kinase inhibitors may provide clinical benefit to shock and/or sepsis patients

Pesticides & Pollinators: Assessing the Impact of Chronic Sublethal Neonicotinoid Exposure on Behavioral Flexibility in Native Bumblebee Species

Neonicotinoid pesticides are widely thought to be a major contributing factor in the recent worldwide decline of insect pollinators, yet mechanisms involved are poorly understood. I examined sublethal effects of chronic oral Clothianidin exposure on the behavior of bumblebees (Bombus impatiens). Foragers exposed to field-realistic doses showed a significantly reduced ability to flexibly switch between different floral resources. Pesticide-exposed foragers also showed a strong bias for selected flowers based on color rather than odor. These results suggest that chronic neonicotinoid exposure can impair neural functions required for foragers to effectively collect floral resources. Future work will determine if these behavioral changes in foragers are sufficient to cause population decline

Fighting the Freshman Fifteen

Every year a new freshman class comes to WPI and battles the stress of rigorous academics and a new style of life with an all you can eat buffet. This leads to WPI students gaining the notorious freshman fifteen, which can easily be prevented. Poor eating habits in college can be the start of lifelong problems such as Obesity or Diabetes

A Species at Risk: Raising Awareness About the Critically Endangered Maui’s Dolphin

The New Zealand Department of Conservation’s protection of the critically endangered Maui’s dolphin (Cephalorhynchus hectori maui) depends heavily upon citizens reporting sightings. Our surveys established that lack of knowledge about the dolphin prevents all but 5% of residents from reporting sightings. To correct this deficiency, we drew on those findings to design improved educational materials and a conceptual smartphone application design. We produced two posters, a bumper sticker, and a tackle box sticker promoting the Maui’s dolphin and DOC’s reporting services. We evaluated them at Seaweek in Auckland