Decay of a superfluid current of ultra-cold atoms in a toroidal trap

Using a numerical implementation of the truncated Wigner approximation, we simulate the experiment reported by Ramanathan et al. in Phys. Rev. Lett. 106, 130401 (2011), in which a Bose-Einstein condensate is created in a toroidal trap and set into rotation via a phase imprinting technique. A potential barrier is then placed in the trap to study the decay of the superflow. We find that the current decays via thermally activated phase slips, which can also be visualized as vortices crossing the barrier region in the radial direction. Adopting the notion of critical velocity used in the experiment, we determine it to be lower than the local speed of sound at the barrier, in contradiction to the predictions of the zero-temperature Gross-Pitaevskii equation. We map out the superfluid decay rate and critical velocity as a function of temperature and observe a strong dependence. Thermal fluctuations offer a partial explanation of the experimentally observed reduction of the critical velocity from the phonon velocity.Comment: 15 pages. 11 figure

Teacher Use of Diagnostic Score Reports for Instructional Decision-Making in the Subsequent Academic Year

Large-scale summative assessment results are typically used for program-evaluation and resource-allocation purposes; however, stakeholders increasingly desire results from large-scale K–12 assessments that inform instruction. Because large-scale summative results are usually delivered after the end of the school year, teacher use of results is reserved for the subsequent academic year. To evaluate use of summative score reports to inform instruction, we conducted a series of teacher interviews and focus groups with 17 teachers in three states. Teachers were asked to describe how they used summative results from the previous administration of a large-scale alternate assessment system in the subsequent academic year. Interview and focus-group transcripts were coded and identified themes related to when and how score reports are delivered; how teachers use results to plan instruction, formulate goals for individualized education programs (IEPs), and create instructional groupings; how teachers talk to parents about results; and what resources best support their use of score reports. Findings demonstrate preliminary support for diagnostic score report use

Developing and Refining a Model for Measuring Implementation Fidelity for an Instructionally Embedded Assessment System

We developed a six-step iterative process for developing and evaluating a model of implementation fidelity appropriate for use in an instructionally embedded assessment system. Our work explicitly connects the literature on theories of actions for assessment systems with the implementation fidelity literature originating from the program evaluation field. The steps include (a) developing a logic model identifying critical and optional implementation components; (b) identifying process data and indicators from the assessment system to represent each component; (c) developing hypotheses about expected patterns in the indicators representing different levels of implementation fidelity and identifying criteria for defining implementation levels; (d) conducting analyses to test the hypotheses; (e) using the results to refine the indicators and criteria; and (f) evaluating strength of the evidence and identifying gaps. This process facilitates measuring action mechanisms and making and testing hypotheses about how critical implementation components are related to intended outcomes of an assessment. Studying implementation fidelity for assessment systems can help us better understand how teachers use assessment results and where additional support may be needed. This work can also help evaluate the extent to which instructionally embedded or formative assessments are implemented as intended and that all students are provided with sufficient opportunity to demonstrate what they have learned

Targeting cellular calcium homeostasis to prevent cytokine-mediated beta cell death

AbstractPro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.</jats:p

Comparison of Short Chain Volatile Fatty Acids in the Breastmilk of Normal and Overweight/Obese Mothers

INTRODUCTION: Health professionals emphasize the importance of breastfeeding in the development of children up to 6-months of age. It is known that short chain volatile fatty acids (SCVFAs) are a byproduct of nutrient fermentation by gut microbiome. These SCVFAs interact with the gut/brain axis and are known to influence infant development. Therefore, a reflection of maternal gut microbiome could likely be found in breastmilk (BM) due to diffusion of SCVFAs across the gut wall into the blood. Previous research in our laboratory has shown differences in the SCVFA fecal fermentation profile between individuals with normal (N) versus overweight/obese (OWOB) body mass index (BMI). Therefore, our research question is: Is there a difference in the relative amount and diversity of SCVFAs in the BM of N compared to OWOB women? We hypothesized that women of N will have a more diverse SCVFA profile than OWOB women in their BM. BM samples (200 ml) were collected from 44 women (22 N (BMI 22.0) and 22 OWOB (BMI 33.7) p2 while OWOB participants had a pre-gravid BMI of greater than 25.0 kg/m2. To our knowledge, this is the first time that SCVFAs have been quantified in the milk of lactating women using GC with an FID detector. This data supports the argument that the pre-gravid BMI of a mother can correlate to the SCVFA profile of her BM. It is unknown if the concentration observed in the mother’s BM in this study has an influence on the neonate’s gut/brain axis and neurological signals, however, we have demonstrated that the SCVFA profile is more diverse in the N BMI mother. Further research is warranted on the influence of maternal BM SCVFA composition on the growth and neurological development of her infant

Verification Testing To Confirm VO2max Attainment in Inactive Women With Obesity

International Journal of Exercise Science 13(4): 1448-1458, 2020. Incidence of obesity is increasing worldwide which is deleterious to health due to its association with increased risk of cardiovascular disease, diabetes, and some cancers. Completion of regular physical activity in individuals with obesity increases maximal oxygen uptake (VO2max). However, whether individuals with obesity can exhibit ‘true’ VO2max is unresolved. This study examined efficacy of verification testing (VER) to identify ‘true’ VO2max in 17 inactive women with obesity (age, body fat, and VO2max = 37 ± 10 yr, 48.7 ± 3.5 %, and 19.4 ± 3.0 mL/kg/min, respectively). They performed ramp exercise (RAMP) to volitional fatigue followed by VER at 105 percent peak power output (%PPO) at baseline and after 3 and 6 wk of high intensity interval training. Results showed no difference in ramp and verification-derived VO2max (1.99 ± 0.37 L/min vs. 1.98 ± 0.32 L/min, 2.00 ± 0.40 L/min vs. 2.04 ± 0.38 L/min, and 2.08 ± 0.34 L/min vs. 2.08 ± 0.32 L/min at 0, 3 and 6 wk of training), although in 40 % of VER tests, VO2max was greater than the RAMP value. Overall, verification testing may be adopted as an additional approach to confirm ‘true’ VO2max attainment in obese women as ramp exercise frequently underestimates VO2max in this population

Variation in Attitudes toward Being a Mother by Race/Ethnicity and Education among Women in the United States

Do differences in experiences of motherhood (e.g., number of children, age at first child, and relationship type) by race/ethnicity and social class mean that attitudes toward motherhood also vary by social location? We examine attitudes toward being a mother among black, Hispanic, Asian, and white women of higher and lower socioeconomic status (SES, as measured by education). Results using the National Survey of Fertility Barriers (N = 4,796) indicate that, despite fertility differences, attitudes toward being a mother differ little between groups. White and Asian women have higher positive attitudes toward being a mother than black and Hispanic women. Only black women appear to distinguish between having and raising children; surprisingly, lower educated Hispanic women are less likely to think that they would be a mother, see motherhood as fulfilling, and think that it is important to have and to raise children compared with higher educated, white women

Electrophysiological properties of human beta-cell lines EndoC-βH1 and -βH2 conform with human beta-cells

© The Author(s) 2018Limited access to human islets has prompted the development of human beta cell models. The human beta cell lines EndoC-βH1 and EndoC-βH2 are increasingly used by the research community. However, little is known of their electrophysiological and secretory properties. Here, we monitored parameters that constitute the glucose-triggering pathway of insulin release. Both cell lines respond to glucose (6 and 20 mM) with 2- to 3-fold stimulation of insulin secretion which correlated with an elevation of [Ca2+]i, membrane depolarisation and increased action potential firing. Similar to human primary beta cells, KATP channel activity is low at 1 mM glucose and is further reduced upon increasing glucose concentration; an effect that was mimicked by the KATP channel blocker tolbutamide. The upstroke of the action potentials reflects the activation of Ca2+ channels with some small contribution of TTX-sensitive Na+ channels. The repolarisation involves activation of voltage-gated Kv2.2 channels and large-conductance Ca2+-activated K+ channels. Exocytosis presented a similar kinetics to human primary beta cells. The ultrastructure of these cells shows insulin vesicles composed of an electron-dense core surrounded by a thin clear halo. We conclude that the EndoC-βH1 and -βH2 cells share many features of primary human β-cells and thus represent a useful experimental model.Peer reviewedFinal Published versio

A multicenter experience using adipose-derived mesenchymal stem cell therapy for cats with chronic, non-responsive gingivostomatitis.

BackgroundThe ability of mesenchymal stem cells (MSCs) to modulate immune responses inspired a series of clinical trials addressing oral mucosal inflammation. We previously reported on the safety and efficacy of fresh, allogeneic and autologous, adipose-derived mesenchymal stem cells (ASCs) to treat feline gingivostomatitis (FCGS), an oral mucosal inflammatory disease that shares similarities with human oral lichen planus.MethodsTo meet clinical demand and goals for future commercialization, we determined the feasibility of shipping fresh ASCs to distant clinics and extended our pilot studies to expand safety and efficacy data for shipped and non-shipped ASCs in a cohort of 18 FCGS cats enrolled locally and at a few different locations within the USA.ResultsWe found that ASCs retained their viability, phenotype, and function after shipment. ASCs administered systemically resulted in a 72% positive response rate, identical to that noted in our previous studies. Cats that responded to ASC therapy had a significant decrease in circulating globulin concentration and histological evidence of decreased CD3+ T cells and CD20+ B cells in the oral mucosa. Responder cats also had significantly decreased percentages of CD8lo cells in blood prior to and at 3 months post-ASC therapy. CD8lo cells may serve as a potential "predictor" for response to systemic ASC therapy.ConclusionFresh feline ASCs can be successfully shipped and administered to cats with FCGS. ASCs modulate the immune response and demonstrate efficacy for chronic oral mucosal inflammatory lesions that are characterized by CD8+ T cell inflammation and T cell activation. FCGS is a potentially useful naturally occurring large animal model of human oral inflammatory diseases

Intersection of two signalling pathways: extracellular nucleotides regulate pollen germination and pollen tube growth via nitric oxide

Plant and animal cells release or secrete ATP by various mechanisms, and this activity allows extracellular ATP to serve as a signalling molecule. Recent reports suggest that extracellular ATP induces plant responses ranging from increased cytosolic calcium to changes in auxin transport, xenobiotic resistance, pollen germination, and growth. Although calcium has been identified as a secondary messenger for the extracellular ATP signal, other parts of this signal transduction chain remain unknown. Increasing the extracellular concentration of ATPγS, a poorly-hydrolysable ATP analogue, inhibited both pollen germination and pollen tube elongation, while the addition of AMPS had no effect. Because pollen tube elongation is also sensitive to nitric oxide, this raised the possibility that a connection exists between the two pathways. Four approaches were used to test whether the germination and growth effects of extracellular ATPγS were transduced via nitric oxide. The results showed that increases in extracellular ATPγS induced increases in cellular nitric oxide, chemical agonists of the nitric oxide signalling pathway lowered the threshold of extracellular ATPγS that inhibits pollen germination, an antagonist of guanylate cyclase, which can inhibit some nitric oxide signalling pathways, blocked the ATPγS-induced inhibition of both pollen germination and pollen tube elongation, and the effects of applied ATPγS were blocked in nia1nia2 mutants, which have diminished NO production. The concurrence of these four data sets support the conclusion that the suppression of pollen germination and pollen tube elongation by extracellular nucleotides is mediated in part via the nitric oxide signalling pathway