The Icelandic Low as a predictor of the Gulf Stream north wall position

The Gulf Stream’s Northwall east of Cape Hatteras marks the abrupt change in velocity and water properties between Slope Sea to the north and Gulf Stream itself. An index of the Northwall position constructed by Taylor and Stephens (1998), called GSNW, is analyzed in terms of interannual changes in the Icelandic Low (IL) pressure anomaly and longitudinal displacement. Sea Surface Temperature (SST) composites suggest that when IL pressure is anomalously low, there are lower temperatures in the Labrador Sea and south of the Grand Banks. Two years later, warm SST anomalies are seen over the Northern Recirculation Gyre and a northward shift in the GSNW occurs. Similar changes in SSTs occur during winters in which the IL is anomalously west resulting in a northward displacement of the GSNW 3 years later. Although time lags of 2 and 3 years between the IL and the GSNW are used in the calculations, it is shown that lags with respect to each atmospheric variable are statistically significant at 5% level over a range of years. Utilizing the appropriate time lags between the GSNW index and the IL pressure and longitude, as well as the Southern Oscillation index, a regression-prediction scheme is developed for forecasting the GSNW with a lead-time of 1 year. This scheme, which uses only prior information, was used to forecast the GSNW from 1994 to 2015. The correlation between the observed and forecasted values for 1994-2014 was 0.60, significant at the 1% level. The predicted value for 2015 indicates a small northward shift of GSNW from its 2014 position

The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors

We present experimental evidences for a ferro-electric transition in the family of quasi one- dimensional conductors (TMTTF)2X. We interpret this new transition in the frame of the combined Mott-Hubbard state taking into account the double action of the spontaneous charge disproportionation on the TMTTF molecular stacks and of the X anionic potentials

A Winogradsky-based culture system shows an association between microbial fermentation and cystic fibrosis exacerbation.

There is a poor understanding of how the physiology of polymicrobial communities in cystic fibrosis (CF) lungs contributes to pulmonary exacerbations and lung function decline. In this study, a microbial culture system based on the principles of the Winogradsky column (WinCF system) was developed to study the physiology of CF microbes. The system used glass capillary tubes filled with artificial sputum medium to mimic a clogged airway bronchiole. Chemical indicators were added to observe microbial physiology within the tubes. Characterization of sputum samples from seven patients showed variation in pH, respiration, biofilm formation and gas production, indicating that the physiology of CF microbial communities varied among patients. Incubation of homogenized tissues from an explant CF lung mirrored responses of a Pseudomonas aeruginosa pure culture, supporting evidence that end-stage lungs are dominated by this pathogen. Longitudinal sputum samples taken through two exacerbation events in a single patient showed that a two-unit drop in pH and a 30% increase in gas production occurred in the tubes prior to exacerbation, which was reversed with antibiotic treatment. Microbial community profiles obtained through amplification and sequencing of the 16S rRNA gene showed that fermentative anaerobes became more abundant during exacerbation and were then reduced during treatment where P. aeruginosa became the dominant bacterium. Results from the WinCF experiments support the model where two functionally different CF microbial communities exist, the persistent Climax Community and the acute Attack Community. Fermentative anaerobes are hypothesized to be the core members of the Attack Community and production of acidic and gaseous products from fermentation may drive developing exacerbations. Treatment targeting the Attack Community may better resolve exacerbations and resulting lung damage

Role of osmolality in blood pressure stability after dialysis and ultrafiltration

Role of osmolality in blood pressure stability after dialysis and ultrafiltration. To clarify the mechanisms involved in the stability of blood pressure during ultrafiltration (UF) alone versus regular dialysis, this study systematically examined the importance of changes in serum potassium, osmolality, and plasma norepinephrine during several dialysis maneuvers. Six stable, normotensive chronic dialysis patients were subjected to a uniform 2 to 3% decrease in body weight during the 2 hours of each dialysis maneuver. Supine to upright mean blood pressure (MBP) decreased (90 to 75 mm Hg, P < 0.05), and three patients became symptomatic after weight loss during regular dialysis, but orthostatic blood pressure was stable (89 to 86 mm Hg, NS) and the patients were asymptomatic after UF and weight loss. Isokalemic regular dialysis did not afford hemodynamic stability, as orthostatic MBP declined (85 to 56 mm Hg, P < 0.02), and four of the patients again were symptomatic after standing. A continuous hypertonic mannitol (25%) infusion during the 2-hour dialysis, however, kept osmolality from decreasing and was associated with a stable orthostatic MBP (89 to 83 mm Hg, NS). A continuous infusion of isotonic mannitol (5%) given in a volume five times that of the hypertonic mannitol failed to prevent orthostatic hypotension (89 to 60 mm Hg, P < 0.005). Plasma norepinephrine concentrations were high in these patients and increased only modestly after weight loss. These results implicate constant plasma osmolality as a critical protective factor of blood pressure during UF and further demonstrate that changes in blood pressure may be dissociated from changes in both serum potassium and plasma norepinephrine concentration.Rôle de l'osmolalité dans la stabilité de la pression artérielle après dialyse et ultrafiltration. Afin de clarifier les mécanismes impliqués dans la stabilité de la pression artérielle au cours de l'ultrafiltration (UF) seule par comparaison avec la dialyse habituelle ce travail évalue systématiquement l'importance des modifications de la kaliémie, de l'osmolalité et de la norépinéphrine plasmatique au cours de plusieurs tactiques de dialyse. Six sujets stables, normotendus, en hémodialyse chronique ont subi une diminution de poids corporel de 2 à 3% au cours des 2 heures de chaque tactique de dialyse. La pression artérielle moyenne a diminué de la position couchée à la position debout (de 90 à 75 mm Hg, P < 0,05) et trois patients sont devenus symptomatiques après la perte de poids au cours de la dialyse habituelle. Par contre la pression artérielle orthostatique a été stable (89 à 86 mm Hg, NS) et les malades ont été asymptomatiques après UF. La dialyse habituelle isokaliémique n'a pas déterminé de stabilité hémodynamique, la pression artérielle moyenne orthostatique a diminué (85 à 56 mm Hg, P < 0,02) et quatre malades ont été à nouveau symptomatiques quand ils se sont levés. Cependant quand une perfusion continue de mannitol hypertonique (25%) pendant les deux heures de la dialyse a empêché la baisse de l'osmolalité la pression artérielle moyenne orthostatique a été stable (89 à 83 mm Hg, NS). Une perfusion continue de mannitol isotonique (5%) apportant un volume cinq fois celui du mannitol hypertonique n'a pas empêché l'hypotention orthostatique (89 à 60 mm Hg, P < 0,005). Les concentrations plasmatiques de norépinéphrine étaient élevées chez ces malades et n'ont que peu augmenté après la perte de poids. Ces résultats impliquent qu'une osmolalité plasmatique constante est un facteur protecteur critique pour la pression artérielle au cours de UF et ils démontrent, de plus, que les modifications de la pression artérielle peuvent être dissociées des modifications du potassium plasmatique et de la concentration de norépinéphrine

A Machine Learning Classifier Trained on Cancer Transcriptomes Detects NF1 Inactivation Signal in Glioblastoma

We have identified molecules that exhibit synthetic lethality in cells with loss of the neurofibromin 1 (NF1) tumor suppressor gene. However, recognizing tumors that have inactivation of the NF1 tumor suppressor function is challenging because the loss may occur via mechanisms that do not involve mutation of the genomic locus. Degradation of the NF1 protein, independent of NF1 mutation status, phenocopies inactivating mutations to drive tumors in human glioma cell lines. NF1 inactivation may alter the transcriptional landscape of a tumor and allow a machine learning classifier to detect which tumors will benefit from synthetic lethal molecules. We developed a strategy to predict tumors with low NF1 activity and hence tumors that may respond to treatments that target cells lacking NF1. Using RNAseq data from The Cancer Genome Atlas (TCGA), we trained an ensemble of 500 logistic regression classifiers that integrates mutation status with whole transcriptomes to predict NF1 inactivation in glioblastoma (GBM)

Three-dimensional localization of ultracold atoms in an optical disordered potential

We report a study of three-dimensional (3D) localization of ultracold atoms suspended against gravity, and released in a 3D optical disordered potential with short correlation lengths in all directions. We observe density profiles composed of a steady localized part and a diffusive part. Our observations are compatible with the self-consistent theory of Anderson localization, taking into account the specific features of the experiment, and in particular the broad energy distribution of the atoms placed in the disordered potential. The localization we observe cannot be interpreted as trapping of particles with energy below the classical percolation threshold.Comment: published in Nature Physics; The present version is the initial manuscript (unchanged compared to version 1); The published version is available online at http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2256.htm

Ambient PM2.5 Exposure Up-regulates the Expression of Costimulatory Receptors on Circulating Monocytes in Diabetic Individuals

BACKGROUND: Exposure of humans to air pollutants such as ozone and particulate matter (PM) may result in airway and systemic inflammation and altered immune function. One putative mechanism may be through modification of cell-surface costimulatory molecules. OBJECTIVES: We examined whether changes in expression of costimulatory molecules on circulating cells are associated with ambient levels of fine PM [aerodynamic diameter ≤ 2.5 μm (PM2.5)] in a susceptible population of diabetic individuals. METHODS: Twenty subjects were studied for 4 consecutive days. Daily measurements of PM2.5 and meteorologic data were acquired on the rooftop of the exam site. Circulating cell-surface markers that mediate innate immune and inflammatory responses were assessed by flow cytometry on each day. Sensitivity analysis was conducted on glutathione S-transferase M1 (GSTM1) genotype, body mass index, and glycosylated hemoglobin A1c (HbA1c) levels to determine their role as effect modifiers. Data were analyzed using random effects models adjusting for season, weekday, and meteorology. RESULTS: We found significantly increased monocyte expression (mean fluorescent intensity) of CD80, CD40, CD86, HLA-DR, and CD23 per 10-μg/m3 increase in PM2.5 at 2- to 4-day lag times after exposure. These findings were significantly higher in obese individuals, in individuals with HbA1c > 7%, and in participants who were GSTM1 null. CONCLUSIONS: Exposure to PM2.5 can enhance antigen-presenting cell phenotypes on circulating cells, which may have consequences in the development of allergic or autoimmune diseases. These effects are amplified in diabetic individuals with characteristics that are associated with insulin resistance or with oxidative stress