1,296 research outputs found

    Detecting the phase transition in a strongly-interacting Fermi gas by unsupervised machine learning

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    We study the critical temperature of the superfluid phase transition of strongly-interacting fermions in the crossover regime between a Bardeen-Cooper-Schrieffer (BCS) superconductor and a Bose-Einstein condensate (BEC) of dimers. To this end, we employ the technique of unsupervised machine learning using an autoencoder neural network which we directly apply to time-of-flight images of the fermions. We extract the critical temperature of the phase transition from trend changes in the data distribution revealed in the latent space of the autoencoder bottleneck.Comment: PRA, in pres

    Machine-learning the phase diagram of a strongly-interacting Fermi gas

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    We determine the phase diagram of strongly correlated fermions in the crossover from Bose-Einstein condensates of molecules (BEC) to Cooper pairs of fermions (BCS) utilizing an artificial neural network. By applying advanced image recognition techniques to the momentum distribution of the fermions, a quantity which has been widely considered as featureless for providing information about the condensed state, we measure the critical temperature and show that it exhibits a maximum on the bosonic side of the crossover. Additionally, we back-analyze the trained neural network and demonstrate that it interprets physically relevant quantities

    Cloning and expression of the rabbit prostaglandin EP2 receptor

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    BACKGROUND: Prostaglandin E(2) (PGE(2)) has multiple physiologic roles mediated by G protein coupled receptors designated E-prostanoid, or "EP" receptors. Evidence supports an important role for the EP(2) receptor in regulating fertility, vascular tone and renal function. RESULTS: The full-length rabbit EP(2) receptor cDNA was cloned. The encoded polypeptide contains 361 amino acid residues with seven hydrophobic domains. COS-1 cells expressing the cloned rabbit EP(2) exhibited specific [(3)H]PGE(2) binding with a K(d) of 19.1± 1.7 nM. [(3)H]PGE(2) was displaced by unlabeled ligands in the following order: PGE(2)>>PGD(2)=PGF(2α)=iloprost. Binding of [(3)H]PGE(2) was also displaced by EP receptor subtype selective agonists with a rank order of affinity consistent with the EP2 receptor (butaprost>AH13205>misoprostol>sulprostone). Butaprost free acid produced a concentration-dependent increase in cAMP accumulation in rabbit EP(2) transfected COS-1 cells with a half-maximal effective concentration of 480 nM. RNase protection assay revealed high expression in the ileum, spleen, and liver with lower expression in the kidney, lung, heart, uterus, adrenal gland and skeletal muscle. In situ hybridization localized EP(2) mRNA to the uterine endometrium, but showed no distinct localization in the kidney. EP2 mRNA expression along the nephron was determined by RT-PCR and its expression was present in glomeruli, MCD, tDL and CCD. In cultured cells EP2 receptor was not detected in collecting ducts but was detected in renal interstitial cells and vascular smooth muscle cells. EP2 mRNA was also detected in arteries, veins, and preglomerular vessels of the kidney. CONCLUSION: EP2 expression pattern is consistent with the known functional roles for cAMP coupled PGE(2) effects in reproductive and vascular tissues and renal interstitial cells. It remains uncertain whether it is also expressed in renal tubules

    Pathological and Transcriptome Changes in the ReninAAV db/db uNx Model of Advanced Diabetic Kidney Disease Exhibit Features of Human Disease

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    The ReninAAV db/db uNx model of diabetic kidney disease (DKD) exhibits hallmarks of advanced human disease, including progressive elevations in albuminuria and serum creatinine, loss of glomerular filtration rate, and pathological changes. Microarray analysis of renal transcriptome changes were more similar to human DKD when compared to db/db eNOS−/− model. The model responds to treatment with arterial pressure lowering (lisinopril) or glycemic control (rosiglitazone) at early stages of disease. We hypothesized the ReninAAV db/db uNx model with advanced disease would have residual disease after treatment with lisinopril, rosiglitazone, or combination of both. To test this, ReninAAV db/db uNx mice with advanced disease were treated with lisinopril, rosiglitazone, or combination of both for 10 weeks. All treatment groups showed significant lowering of urinary albumin to creatinine ratio compared to baseline; however, only combination group exhibited lowering of serum creatinine. Treatment improved renal pathological scores compared to baseline values with residual disease evident in all treatment groups when compared to db/m controls. Gene expression analysis by TaqMan supported pathological changes with increased fibrotic and inflammatory markers. The results further validate this model of DKD in which residual disease is present when treated with agents to lower arterial pressure and glycemic control

    Cyclooxygenase-2 expression is associated with the renal macula densa of patients with Bartter-like syndrome

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    Cyclooxygenase-2 expression is associated with the renal macula densa of patients with Bartter-like syndrome.BackgroundBartter-like syndrome (BLS) is a heterogeneous set of congenital tubular disorders that is associated with significant renal salt and water loss. The syndrome is also marked by increased urinary prostaglandin E2 (PGE2) excretion. In rodents, salt and volume depletion are associated with increased renal macula densa cyclooxygenase-2 (COX-2) expression. The expression of COX-2 in human macula densa has not been demonstrated. The present studies examined whether COX-2 can be detected in macula densa from children with salt-wasting BLS versus control tissues.MethodsThe intrarenal distribution of COX-2 protein and mRNA was analyzed by immunohistochemistry and in situ hybridization in 12 patients with clinically and/or genetically confirmed BLS. Renal tissue rejected for transplantation, from six adult patients not affected by BLS, was also examined.ResultsThe expression of COX-2 immunoreactive protein was observed in cells of the macula densa in 8 out 11 patients with BLS. In situ hybridization confirmed the expression of COX-2 mRNA in the macula densa in 6 out of 10 cases. COX-2 protein was also detected in the macula densa in a patient with congestive heart failure. The expression of COX-2 immunoreactive protein was not observed in cells associated with the macula densa in kidneys from patients without disorders associated with hyper-reninemia.ConclusionThese studies demonstrate that COX-2 may be detected in the macula densa of humans. Since macula densa COX-2 was detected in cases of BLS, renal COX-2 expression may be linked to volume and renin status in humans, as well as in animals

    Precautionary Regulation in Europe and the United States: A Quantitative Comparison

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    Much attention has been addressed to the question of whether Europe or the United States adopts a more precautionary stance to the regulation of potential environmental, health, and safety risks. Some commentators suggest that Europe is more risk-averse and precautionary, whereas the US is seen as more risk-taking and optimistic about the prospects for new technology. Others suggest that the US is more precautionary because its regulatory process is more legalistic and adversarial, while Europe is more lax and corporatist in its regulations. The flip-flop hypothesis claims that the US was more precautionary than Europe in the 1970s and early 1980s, and that Europe has become more precautionary since then. We examine the levels and trends in regulation of environmental, health, and safety risks since 1970. Unlike previous research, which has studied only a small set of prominent cases selected non-randomly, we develop a comprehensive list of almost 3,000 risks and code the relative stringency of regulation in Europe and the US for each of 100 risks randomly selected from that list for each year from 1970 through 2004. Our results suggest that: (a) averaging over risks, there is no significant difference in relative precaution over the period, (b) weakly consistent with the flip-flop hypothesis, there is some evidence of a modest shift toward greater relative precaution of European regulation since about 1990, although (c) there is a diversity of trends across risks, of which the most common is no change in relative precaution (including cases where Europe and the US are equally precautionary and where Europe or the US has been consistently more precautionary). The overall finding is of a mixed and diverse pattern of relative transatlantic precaution over the period

    A simple framework for analysing the impact of economic growth on non-communicable diseases

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    YesNon-communicable diseases (NCDs) are currently the leading cause of death worldwide. In this paper, we examine the channels through which economic growth affects NCDs’ epidemiology. Following a production function approach, we develop a basic technique to break up the impact of economic growth on NCDs into three fundamental components: (1) a resource effect; (2) a behaviour effect; and (3) a knowledge effect. We demonstrate that each of these effects can be measured as the product of two elasticities, the output and income elasticity of the three leading factors influencing the frequency of NCDs in any population: health care, healthrelated behaviours and lifestyle, and medical knowledge
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