Spectroscopic Constants and Vibrational Frequencies for l-C3H+ and Isotopologues from Highly-Accurate Quartic Force Fields: The Detection of l-C3H+ in the Horsehead Nebula PDR Questioned

Very recently, molecular rotational transitions observed in the photon-dominated region of the Horsehead nebula have been attributed to l-C3H+. In an effort to corroborate this finding, we employed state-of-the art and proven high-accuracy quantum chemical techniques to compute spectroscopic constants for this cation and its isotopologues. Even though the B rotational constant from the fit of the observed spectrum and our computations agree to within 20 MHz, a typical level of accuracy, the D rotational constant differs by more than 40%, while the H rotational constant differs by three orders of magnitude. With the likely errors in the rotational transition energies resulting from this difference in D on the order of 1 MHz for the lowest observed transition (J = 4 <- 3) and growing as J increases, the assignment of the observed rotational lines from the Horsehead nebula to l-C3H+ is questionable

Effects of Fluid Shear on Endothelial Cell Response to Inflammation.

The endothelium is a thin monolayer of cells that regulates several important processes including maintaining blood pressure, clotting, angiogenesis, barrier function, and inflammation. Inflammation, a natural process by which foreign particles are eliminated from vascular tissue, is of considerable importance due its prevalent role in a number of disease pathologies. Endothelial response to inflammation results in differential expression of cell adhesion molecules, such as E-selectin, on the apical surface facing the bloodstream. Patterns and duration of adhesion molecule expression is critical to the balance between healthy and pathogenic inflammatory response. Chronic inflammation, due to endothelial dysfunction leads to a number of diseases, including neurological disorders, cancers and metastatic tumor growths, and cardiovascular diseases. Despite its prominent roles in disease pathogenesis, endothelial response has yet to be fully understood due to current in vitro models failing to fully replicate relevant endothelial inflammatory response under human physiological conditions. The influence of fluid shear on E-selectin expression due to inflammatory activation is investigated through simultaneous co-stimulation with fluid shear and interleukin-1β of naïve and preconditioned ECs using a novel laminar flow apparatus designed to study the broader time frame over which chronic inflammation is relevant. Naïve cells exposed to shear-cytokine activation display high E-selectin expression for up to 24 hr with peak expression occurring after 8-12 hr of activation contrary to the commonly observed 4-6 hr peak in statically activated cells. High shear preconditioned cells exhibited either elevated or muted E-selectin expression during acute and chronic time frames, respectively, depending on the preconditioning and subsequent shear-cytokine activation durations. The 8-12 hr peak E-selectin expression time in shear-cytokine activated cells coincides with the time frame observed for shear-exposed ECs to shift from a cobblestone to elongated morphology, highlighting a role for cell morphology determining EC response. Overall, the presented data suggest that high laminar shear enhances acute EC response to interleukin-1ß in naïve ECs as may be found in the pathological setting of ischemia/reperfusion injury while in preconditioned ECs, high laminar shear confers rapid E-selectin downregulation to protect against chronic inflammation. However, high laminar shear is protective against TNFα-induced acute and chronic inflammatory response.Ph.D.Chemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91577/1/rbhuang_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91577/2/rbhuang_2.pd

Quantum magnetism with multicomponent polar molecules in an optical lattice

We consider bosonic dipolar molecules in an optical lattice prepared in a mixture of different rotational states. The 1/r^3 interaction between molecules for this system is produced by exchanging a quantum of angular momentum between two molecules. We show that the Mott states of such systems have a large variety of non-trivial spin orderings including a state with ordering wave vector that can be changed by tilting the lattice. As the Mott insulating phase is melted, we also describe several exotic superfluid phases that will occur

Active microscope stabilization in three dimensions using image correlation

BACKGROUND: Super-resolution microscopy techniques are often extremely susceptible to sample drift due to their high spatial resolution and the long time needed for data acquisition. While several techniques for stabilizing against drift exist, many require complicated additional hardware or intrusive sample preparations. We introduce a method that requires no additional sample preparation, is simple to implement and simultaneously corrects for x, y and z drift. RESULTS: We use bright-field images of the specimen itself to calculate drift in all three dimensions: x, y and z. Bright-field images are acquired on an inexpensive CCD. By correlating each acquired bright-field image with an in-focus and two out-of-focus reference images we determine and actively correct for drift at rates of a few Hertz. This method can maintain stability to within 10 nm for x and y and 20 nm for z over several minutes. CONCLUSION: Our active drift stabilization system is capable of simultaneously compensating x, y and z drift through an image-based correlation method that requires no special sample treatment or extensive microscope modifications. While other techniques may provide better stability, especially for higher frequency drift, our method is easy to implement and widely applicable in terms of both sample type and microscopy technique

Discovering the Hidden Facts of User-Dispatcher Interactions via Text-based Reporting Systems for Community Safety

Recently, an increasing number of safety organizations in the U.S. have incorporated text-based risk reporting systems to respond to safety incident reports from their community members. To gain a better understanding of the interaction between community members and dispatchers using text-based risk reporting systems, this study conducts a system log analysis of LiveSafe, a community safety reporting system, to provide empirical evidence of the conversational patterns between users and dispatchers using both quantitative and qualitative methods. We created an ontology to capture information (e.g., location, attacker, target, weapon, start-time, and end-time, etc.) that dispatchers often collected from users regarding their incident tips. Applying the proposed ontology, we found that dispatchers often asked users for different information across varied event types (e.g., Attacker for Abuse and Attack events, Target for Harassment events). Additionally, using emotion detection and regression analysis, we found an inconsistency in dispatchers' emotional support and responsiveness to users' messages between different organizations and between incident categories. The results also showed that users had a higher response rate and responded quicker when dispatchers provided emotional support. These novel findings brought significant insights to both practitioners and system designers, e.g., AI-based solutions to augment human agents' skills for improved service quality