Quantitative acoustic models for superfluid circuits

We experimentally realize a highly tunable superfluid oscillator circuit in a quantum gas of ultracold atoms and develop and verify a simple lumped-element description of this circuit. At low oscillator currents, we demonstrate that the circuit is accurately described as a Helmholtz resonator, a fundamental element of acoustic circuits. At larger currents, the breakdown of the Helmholtz regime is heralded by a turbulent shedding of vortices and density waves. Although a simple phase-slip model offers qualitative insights into the circuit's resistive behavior, our results indicate deviations from the phase-slip model. A full understanding of the dissipation in superfluid circuits will thus require the development of empirical models of the turbulent dynamics in this system, as have been developed for classical acoustic systems.Comment: 12 pages, 9 figure

Nurse-patient communication on the south Texas border: Negotiating language and cultural discordance during the COVID-19 pandemic

Throughout the COVID-19 pandemic, medical professionals have experienced unforeseen and often under-discussed hurdles to meeting the surging demand for patient care. In particular, practitioners in under-resourced areas have faced enormous barriers when attempting to adequately address the swell in demand. Analyzing these tensions through the growing body of literature on patient communication during the COVID-19 pandemic, this article centers the work experiences of registered nurses serving on the frontlines of the South Texas-Mexico border of Laredo, Texas. Using a qualitative method of semi-structured and in-depth interviews with nurses working inside two COVID-19 hospital units, our thematic analysis reveals the work challenges generated by language discordance and cultural differences experienced between travel nurses, patients, and their families. Our findings further exposed the added workload and work strain generated from the language and cultural barriers experienced by local bilingual nurses, tracking how during a global pandemic such barriers place material strain on nurses' workload

A persistent, TTX-sensitive sodium current in an invertebrate neuron with neurosecretory ultrastructure

In the CNS of the giant barnacle (Balanus nubilus) a single pair of large neuronal somata (cross-commissural, or CC, cells), located near the entry of the median ocellar nerve, occasionally displays a prominent whitish luster. These somata have ultrastructure typical of neurosecretory cells: numerous Golgi complexes and abundant, large dense-cored vesicles (DCVs; size range, 75-275 nm). Injection of a CC cell with cobalt tracer shows that it arborizes over a 7 mm length of the contralateral peripheral nerve out of which it projects. The processes of the arbor are profuse and varicose; the varicosities are packed with DCVs similar to those in the soma. Stimulation of a single CC cell causes a substantial decrease in the number of DCVs and increases the incidence of clusters of small electron-lucent vesicles, as well as the occurrence of large electron-lucent vesicles and membrane-bound cisternae. We studied ionic currents flowing across this cell's somatic membrane with a single-electrode voltage clamp. Unusual among these currents is an inward current that is blocked by TTX but is essentially noninactivating. In current clamp, this "persistent" current causes the action potential to be prolonged (seconds) if opposing outward current is blocked with 4-aminopyridine. The inward current is carried by Na. Its amplitude depends on the external Na concentration, it is blockable by TTX, and it persists when the cell is bathed in Ca-free saline and/or Co. Other currents present in this cell include an outward current similar to molluscan A-current and a Ca current that contributes to the action potential (Stockbridge and Ross, 1986). The persistent Na current is partially activated at the cell's resting potential and, thus, may participate in determining the frequency of its impulse activity

Environmental Reporting by the Fortune 50 Firms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42398/1/267-21-6-865_21n6p865.pd

Damping device for a stationary labyrinth seal

A stationary labyrinth seal system includes a seal housing having an annular cavity, a plurality of damping devices, and a retaining ring. The damping devices are positioned within the annular cavity and are maintained within the annular cavity by the retaining ring

Chimpanzees demonstrate individual differences in social information use

Studies of transmission biases in social learning have greatly informed our understanding of how behaviour patterns may diffuse through animal populations, yet within-species inter-individual variation in social information use has received little attention and remains poorly understood. We have addressed this question by examining individual performances across multiple experiments with the same population of primates. We compiled a dataset spanning 16 social learning studies (26 experimental conditions) carried out at the same study site over a 12-year period, incorporating a total of 167 chimpanzees. We applied a binary scoring system to code each participant’s performance in each study according to whether they demonstrated evidence of using social information from conspecifics to solve the experimental task or not (Social Information Score—‘SIS’). Bayesian binomial mixed effects models were then used to estimate the extent to which individual differences influenced SIS, together with any effects of sex, rearing history, age, prior involvement in research and task type on SIS. An estimate of repeatability found that approximately half of the variance in SIS was accounted for by individual identity, indicating that individual differences play a critical role in the social learning behaviour of chimpanzees. According to the model that best fit the data, females were, depending on their rearing history, 15–24% more likely to use social information to solve experimental tasks than males. However, there was no strong evidence of an effect of age or research experience, and pedigree records indicated that SIS was not a strongly heritable trait. Our study offers a novel, transferable method for the study of individual differences in social learning

High Performance Accountable Care: Building on Success and Learning From Experience

Presents the rationale for creating accountable care organizations, promising models, and the Commonwealth Fund Commission on a High Performance Health System's recommendations for implementing ACOs widely to achieve improved quality and efficiency

A human embryonic kidney 293T cell line mutated at the Golgi -mannosidase II locus

Disruption of Golgi -mannosidase II activity can result in type II congenital dyserythropoietic anemia and can induce lupus-like autoimmunity in mice. Here, we isolate a mutant human embryonic kidney (HEK) 293T cell line, called Lec36, that displays sensitivity to ricin that lies between the parental HEK 293T cells, whose secreted and membrane-expressed proteins are dominated by complex-type glycosylation, and 293S Lec1 cells, which only produce oligomannose-type N-linked glycans. The stem cell marker, 19A, was transiently expressed in the HEK 293T Lec36 cells, and in parental HEK 293T cells with and without the potent Golgi -mannosidase II inhibitor, swainsonine. Negative-ion nano-electrospray ionization mass spectra of the 19A N-linked glycans from HEK 293T Lec36 and swainsonine-treated HEK 293T cells were qualitatively indistinguishable and, as shown by collision-induced dissociation spectra, dominated by hybrid-type glycosylation. Nucleotide sequencing revealed mutations in each allele of MAN2A1, the gene encoding Golgi -mannosidase II: a point mutation in one allele mapping to the active site and an in-frame deletion of twelve-nucleotides in the other. Expression of wild-type but not the mutant MAN2A1 alleles in Lec36 cells restored processing of the 19A reporter glycoprotein to complex-type glycosylation. The Lec36 cell line will be useful for expressing therapeutic glycoproteins with hybrid-type glycans and provides a sensitive host for detecting mutations in human MAN2A1 causing type II congenital dyserythropoietic anemia

The evolution of substructure II: linking dynamics to environment

We present results from a series of high-resolution N-body simulations that focus on the formation and evolution of eight dark matter halos, each of order a million particles within the virial radius. We follow the time evolution of hundreds of satellite galaxies with unprecedented time resolution, relating their physical properties to the differing halo environmental conditions. The self-consistent cosmological framework in which our analysis was undertaken allows us to explore satellite disruption within live host potentials, a natural complement to earlier work conducted within static potentials. Our host halos were chosen to sample a variety of formation histories, ages, and triaxialities; despite their obvious differences, we find striking similarities within the associated substructure populations. Namely, all satellite orbits follow nearly the same eccentricity distribution with a correlation between eccentricity and pericentre. We also find that the destruction rate of the substructure population is nearly independent of the mass, age, and triaxiality of the host halo. There are, however, subtle differences in the velocity anisotropy of the satellite distribution. We find that the local velocity bias at all radii is greater than unity for all halos and this increases as we move closer to the halo centre, where it varies from 1.1 to 1.4. For the global velocity bias we find a small but slightly positive bias, although when we restrict the global velocity bias calculation to satellites that have had at least one orbit, the bias is essentially removed.Comment: 14 pages, 14 figures, MNRAS in pres