Adaption of evolutionary programming to the prediction of solar flares

Adapting evolutionary programming to prediction of solar flare

Pigment production and isotopic fractionations in continuous culture: okenone producing purple sulfur bacteria Part II

Okenone is a carotenoid pigment unique to certain members of Chromatiaceae, the dominant family of purple sulfur bacteria (PSB) found in euxinic photic zones. Diagenetic alteration of okenone produces okenane, the only recognized molecular fossil unique to PSB. The in vivo concentrations of okenone and bacteriochlorophyll a (Bchl a) on a per cell basis were monitored and quantified as a function of light intensity in continuous cultures of the purple sulfur bacterium Marichromatium purpuratum (Mpurp1591). We show that okenone-producing PSB have constant bacteriochlorophyll to carotenoid ratios in light-harvesting antenna complexes. The in vivo concentrations of Bchl a, 0.151 ± 0.012 fmol cell^(−1), and okenone, 0.103 ± 0.012 fmol cell^(−1), were not dependent on average light intensity (10–225 Lux) at both steady and non-steady states. This observation revealed that in autotrophic continuous cultures of Mpurp1591, there was a constant ratio for okenone to Bchl a of 1:1.5. Okenone was therefore constitutively produced in planktonic cultures of PSB, regardless of light intensity. This confirms the legitimacy of okenone as a signature for autotrophic planktonic PSB and by extrapolation water column euxinia. We measured the δ^(13)C, δ^(15)N, and δ^(34)S bulk biomass values from cells collected daily and determined the isotopic fractionations of Mpurp1591. There was no statistical relationship in the bulk isotope measurements or stable isotope fractionations to light intensity or cell density under steady and non-steady-state conditions. The carbon isotope fractionation between okenone and Bchl a with respect to overall bulk biomass (^(13)ε_pigment – biomass) was 2.2 ± 0.4‰ and −4.1 ± 0.9‰, respectively. The carbon isotopic fractionation (^(13)ε_pigment-CO_2) for the production of pigments in PSB is more variable than previously thought with our reported values for okenone at −15.5 ± 1.2‰ and −21.8 ± 1.7‰ for Bchl a

Toward autonomous spacecraft

Ways in which autonomous behavior of spacecraft can be extended to treat situations wherein a closed loop control by a human may not be appropriate or even possible are explored. Predictive models that minimize mean least squared error and arbitrary cost functions are discussed. A methodology for extracting cyclic components for an arbitrary environment with respect to usual and arbitrary criteria is developed. An approach to prediction and control based on evolutionary programming is outlined. A computer program capable of predicting time series is presented. A design of a control system for a robotic dense with partially unknown physical properties is presented

Ecologically and geologically relevant isotope signatures of C, N, and S: okenone producing purple sulfur bacteria part I

Purple sulfur bacteria (PSB) are known to couple the carbon, nitrogen, and sulfur cycling in euxinic environments. This is the first study with multiple strains and species of okenone-producing PSB to examine the carbon (C), nitrogen (N), and sulfur (S) metabolisms and isotopic signatures in controlled laboratory conditions, investigating what isotopic fractionations might be recorded in modern environments and the geologic record. PSB play an integral role in the ecology of euxinic environments and produce the unique molecular fossil okenane, derived from the diagenetic alteration of the carotenoid pigment okenone. Cultures of Marichromatium purpuratum 1591 (Mpurp1591) were observed to have carbon isotope fractionations (13_ε_biomass – CO_2), via RuBisCO, ranging from −16.1 to −23.2‰ during exponential and stationary phases of growth. Cultures of Thiocapsa marina 5653 (Tmar5653) and Mpurp1591 had a nitrogen isotope fractionation (15_ε_biomass – NH4) of −15‰, via glutamate dehydrogenase, measured and recorded for the first time in PSB. The δ^(34)S_VCDT values and amount of stored elemental sulfur for Mpurp1591 cells grown autotrophically and photoheterotrophically were dependent upon their carbon metabolic pathways. We show that PSB may contribute to the isotopic enrichments observed in modern and ancient anoxic basins. In a photoheterotrophic culture of Mpurp1591 that switched to autotrophy once the organic substrate was consumed, there were bulk biomass δ13C values that span a broader range than recorded across the Late Devonian, Permian–Triassic, Triassic–Jurassic, and OAE2 mass extinction boundaries. This finding stresses the complexities in interpreting and assigning δ13C values to bulk organic matter preserved in the geologic record

Annular pancreas: endoscopic and pancreatographic findings from a tertiary referral ERCP center

Background and Aims Annular pancreas is a congenital anomaly whereby pancreatic tissue encircles the duodenum. Current knowledge of endoscopic findings of annular pancreas is limited to small case series. The aim of this study was to describe the endoscopic and pancreatographic findings of patients with annular pancreas at a large tertiary care ERCP center. Methods This is a retrospective observational study. Our Institutional Review Board–approved, prospectively collected ERCP database was queried for cases of annular pancreas. The electronic medical records were searched for patient and procedure-related data. Results From January 1, 1994, to December 31, 2016, 46 patients with annular pancreas underwent ERCP at our institution. Index ERCP was technically successful in 42 patients (91.3%), and technical success was achieved in all 46 patients (100%) after 2 attempts, when required. A duodenal narrowing or ring was found in most patients (n = 39, 84.8%), yet only 2 (4.3%) had retained gastric contents. Pancreas divisum was found in 21 patients (45.7%), 18 of which were complete divisum. Pancreatobiliary neoplasia was the indication for ERCP in 7 patients (15.2%). Pancreatographic findings consistent with chronic pancreatitis were noted in 15 patients (32.6%) at the index ERCP. Conclusion This is the largest series describing the endoscopic and pancreatographic findings of patients with annular pancreas. We found that 45.7% of patients had concurrent pancreas divisum. Endoscopic therapy was successful in most patients at our institution after 1 ERCP, and in all patients after a second ERCP. Nearly one-third of patients had findings consistent with chronic pancreatitis at the time of index ERCP. It is unclear whether this may be a feature of the natural history of annular pancreas

Optimizing the Stark-decelerator beamline for the trapping of cold molecules using evolutionary strategies

We demonstrate feedback control optimization for the Stark deceleration and trapping of neutral polar molecules using evolutionary strategies. In a Stark-decelerator beamline pulsed electric fields are used to decelerate OH radicals and subsequently store them in an electrostatic trap. The efficiency of the deceleration and trapping process is determined by the exact timings of the applied electric field pulses. Automated optimization of these timings yields an increase of 40 % of the number of trapped OH radicals.Comment: 7 pages, 4 figures (RevTeX) (v2) minor corrections (v3) no changes to manuscript, but fix author list in arXiv abstrac

Prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis with rectal non-steroidal anti-inflammatory drugs

Acute pancreatitis is the most common and feared adverse event associated with performance of endoscopic retrograde cholangiopancreatography (ERCP). Unremitting effort has been made for over 40 years to minimize the frequency and severity of this complication. Recently, the use of rectal non-steroidal anti-inflammatory drugs (NSAIDs) have opened a new era for its prevention. This review focuses on the role of NSAIDs in pancreatitis, the pharmacokinetics of these agents, and summarizes the results of clinical trials with rectal NSAIDs alone and combination regimens in the prevention of post-ERCP pancreatitis

Characterization of pysio-chemical properties of novel one stop chemical method in preparations of copper nanofluids and possible explanations

Nanofluid is a dilute suspension containing particles in nanometer sized which are dispersed in the base fluid like ethylene glycol or water. Nanofluid is one of the crucial discovery in modern science which found to be having better thermal properties compared with conventional fluids like water or ethylene glycol thus makes it ideal to be applied and utilized in many areas in heat transfer area such as cooling, utilized as fluid for heat echangers and etc. Besides, the nanofluid with the improved thermal properties could solve the problem faced by various industries in the area of heat transfer. For example, in the semiconductor industry, the needs of superior cooling coolant are very crucialJn this paper, presents about preparation of copper nanofluid using novel one stop chemical method by reducing copper sulphate pentahydrate using reduction agent which is sodium hypophosphite in ethylene glycol as base fluids. The obtained nanofluid by using this novel one stop method is more stable besides cheaper and faster compared with two stop method whereby in the two step method, the production of the nanoparticles and the nanofluids are isolated. The process of drying, storage and transportation of the nanoparticles that takes place in two step method have cause the agglomeration and sedimentation of the nanofluids. As the result, the agglomeration could cause the settlement and clogging in the microchannel besides reduce the thermal conductivity. Therefore in the novel one stop method the production of the nanoparticles and the nanofluids are combined and not separated to avoid the process of drying, storage and transportation of nanoparticles. Meanwhile the nanofluid that obtained were analyzed using Transmission Electron Microscopy (TEM), UV-Vis Spectrophotometer, Viscometer and Fourier Transform Infared Spectroscopy (FTIR). The effect and influences of pH and dilution to the reaction rate and properties of nanofluid were also investigated