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Search Results: 1 - 10 of 8194 matches for " JOSE; PAINEMAL "
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SECONDARY METABOLITES FROM MARINE PENICILLIUM BREVICOMPACTUM
JUANA ROVIROSA,ANA DIAZ-MARRERO,JOSE DARIAS,KARIN PAINEMAL
Journal of the Chilean Chemical Society , 2006,
Abstract: In a screening of Basidiomycete cultures isolated from marine invertebrates collected along the Chilean coastline for the production of antibiotics we identified a Penicillium brevicompactum strain as a producer of metabolites inhibiting the growth of bacteria and fungi. Bioactivity guided purification resulted in the isolation of four known metabolites. Their structures were elucidated by spectroscopic methods
SECONDARY METABOLITES FROM MARINE PENICILLIUM BREVICOMPACTUM
ROVIROSA,JUANA; DIAZ-MARRERO,ANA; DARIAS,JOSE; PAINEMAL,KARIN; SAN MARTIN,AURELIO;
Journal of the Chilean Chemical Society , 2006, DOI: 10.4067/S0717-97072006000100004
Abstract: in a screening of basidiomycete cultures isolated from marine invertebrates collected along the chilean coastline for the production of antibiotics we identified a penicillium brevicompactum strain as a producer of metabolites inhibiting the growth of bacteria and fungi. bioactivity guided purification resulted in the isolation of four known metabolites. their structures were elucidated by spectroscopic methods
Cancer patients in ICU
Claudio Painemal
Medwave , 2011,
Abstract:
The first aerosol indirect effect quantified through airborne remote sensing during VOCALS-REx
D. Painemal,P. Zuidema
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2013,
Abstract: The first aerosol indirect effect (1AIE) is investigated using a combination of in situ and remotely-sensed aircraft (NCAR C-130) observations acquired during VOCALS-REx over the southeast Pacific stratocumulus cloud regime. Satellite analyses have previously identified a high albedo susceptibitility to changes in cloud microphysics and aerosols over this region. The 1AIE was broken down into the product of two independently-estimated terms: the cloud aerosol interaction metric ACIτ =dlnτ/dlnNa|LWP , and the relative albedo (A) susceptibility SR-τ =dA/3dlnτ|LWP, with τ and Na denoting retrieved cloud optical thickness and in situ aerosol concentration respectively and calculated for fixed intervals of liquid water path (LWP). ACIτ was estimated by combining in situ Na sampled below the cloud, with τ and LWP derived from, respectively, simultaneous upward-looking broadband irradiance and narrow field-of-view millimeter-wave radiometer measurements, collected at 1 Hz during four eight-hour daytime flights by the C-130 aircraft. ACIτ values were typically large, close to the physical upper limit (0.33), with a modest increase with LWP. The high ACIτ values slightly exceed values reported from many previous in situ airborne studies in pristine marine stratocumulus and reflect the imposition of a LWP constraint and simultaneity of aerosol and cloud measurements. SR-τ increased with LWP and τ, reached a maximum SR-τ (0.086) for LWP (τ) of 58 g m 2 (~14), and decreased slightly thereafter. The 1AIE thus increased with LWP and is comparable to a radiative forcing of 3.2– 3.8 W m 2 for a 10% increase in Na, exceeding previously-reported global-range values. The aircraft-derived values are consistent with satellite estimates derived from instantaneous, collocated Clouds and the Earth's Radiant Energy System (CERES) albedo and MOderate resolution Imaging Spectroradiometer (MODIS)-retrieved droplet number concentrations at 50 km resolution. The consistency of the airborne and satellite estimates, despite their independent approaches, differences in observational scales, and retrieval assumptions, is hypothesized to reflect the ideal remote sensing conditions for these homogeneous clouds. We recommend the southeast Pacific for regional model assessments of the first aerosol indirect effect on this basis. This airborne remotely-sensed approach towards quantifying 1AIE should in theory be more robust than in situ calculations because of increased sampling. However, although the technique does not explicitly depend on a remotely-derived cloud droplet number concentration (Nd), the at-times unrealistically-high Nd values suggest more emphasis on accurate airborne radiometric measurements is needed to refine this approach.
Microphysical variability in southeast Pacific Stratocumulus clouds: synoptic conditions and radiative response
D. Painemal ,P. Zuidema
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2010,
Abstract: Synoptic and satellite-derived cloud property variations for the southeast Pacific stratocumulus region associated with changes in coastal satellite-derived cloud droplet number concentrations (Nd) are explored. MAX and MIN Nd composites are defined by the top and bottom terciles of daily area-mean Nd values over the Arica Bight, the region with the largest mean oceanic Nd, for the five October months of 2001, 2005, 2006, 2007 and 2008. The ability of the satellite retrievals to capture composite differences is assessed with ship-based data. Nd and ship-based accumulation mode aerosol concentrations (Na) correlate well (r = 0.65), with a best-fit aerosol activation value dln Nddln Na of 0.56 for pixels with Nd>50 cm 3. The adiabatically-derived MODIS cloud depths also correlate well with the ship-based cloud depths (r=0.7), though are consistently higher (mean bias of almost 60 m). The MAX-Nd composite is characterized by a weaker subtropical anticyclone and weaker winds both at the surface and the lower free troposphere than the MIN-Nd composite. The MAX-Nd composite clouds over the Arica Bight are thinner than the MIN-Nd composite clouds, have lower cloud tops, lower near-coastal cloud albedos, and occur below warmer and drier free tropospheres (as deduced from radiosondes and NCEP Reanalysis). CloudSat radar reflectivities indicate little near-coastal precipitation. The co-occurrence of more boundary-layer aerosol/higher Nd within a more stable atmosphere suggests a boundary layer source for the aerosol, rather than the free troposphere. The MAX-Nd composite cloud thinning extends offshore to 80° W, with lower cloud top heights out to 95° W. At 85° W, the top-of-atmosphere shortwave fluxes are significantly higher (~50%) for the MAX-Nd composite, with thicker, lower clouds and higher cloud fractions than for the MIN-Nd composite. The change in Nd at this location is small (though positive), suggesting that the MAX-MIN Nd composite differences in radiative properties primarily reflects synoptic changes. Circulation anomalies and a one-point spatial correlation map reveal a weakening of the 850 hPa southerly winds decreases the free tropospheric cold temperature advection. The resulting increase in the static stability along 85° W is highly correlated to the increased cloud fraction, despite accompanying weaker free tropospheric subsidence.
Synoptically-induced variability in the microphysical properties of the South East Pacific stratocumulus deck
D. Painemal,P. Zuidema
Atmospheric Chemistry and Physics Discussions , 2009,
Abstract: Synoptic variations associated with changes in satellite-derived cloud droplet number concentrations (Nd) for the southeast Pacific stratocumulus deck were examined using a composite analysis applied to daily values from the five October months of 2001, 2005, 2006, 2007 and 2008. MAX and MIN Nd composites were defined by the top and bottom terciles of daily area-mean Nd values over the Arica Bight, the region with the largest mean oceanic Nd. Nd and ship-based accumulation mode aerosol concentrations (Na) correlate well (r=0.65), with a best-fit aerosol activation value dln Nddln Na of 0.53 for pixels with Nd>50 cm 3. The adiabatically-derived MODIS cloud depths also correlate well with the ship-based cloud depths (r=0.7), though are consistently higher (mean bias of almost 60 m). The MAX-Nd composite is characterized by a weaker subtropical anticyclone and weaker winds both at the surface and the lower free troposphere than the MIN-Nd composite. The MAX-Nd composite clouds over the Arica Bight are thinner than the MIN-Nd composite clouds, have lower cloud tops, and occur within warmer, drier free tropospheres (as deduced from radiosondes) that imply greater coastal subsidence. The cloud thinning compensates radiatively for increased reflectance from increases in Nd, most apparent near the coast. CloudSat radar reflectivities do not imply significant aerosol scavenging by precipitation near the coast, indicating that variability in wind transport contributes to the aerosol variability. The co-occurrence of more boundary-layer aerosol/higher Nd within a more stable atmosphere suggests a boundary layer source for the aerosol, rather than the free troposphere. Along 85° W, the top-of-atmosphere shortwave fluxes are significantly higher (~50%) for the MAX-Nd composite than for the MIN-Nd composite, with thicker clouds and higher cloud fractions. The change in Nd at this location is small (though positive), so that the composite difference primarily reflects synoptic changes. A one-point spatial correlation map reveals anomalous northerly winds at 850 hPa account for an anomalous warm temperature advection. The increase in the static stability along 85° W is highly correlated to the increased cloud fraction, despite accompanying weaker free tropospheric subsidence. This synoptic impact on offshore cloud properties is arguably our most radiatively important finding, and draws attention to the free tropospheric meridional flow as a meteorological control.
Metabolites From The Marine Fungus Cladosporium Cladosporioides
San-Martín,A.; Painemal,K.; Díaz,Y.; Martínez,C.; Rovirosa,J.;
Anales de la Asociaci?3n Qu?-mica Argentina , 2005,
Abstract: p-methylbenzoic acid and peroxyergosterol were isolated and identified by spectroscopic methods from cultures of the fungus cladosporium cladosporioides isolated from a marine sponge. to the best of our knowledge, this is the first time that p-methylbenzoic acid had been isolated as a natural product.
Revisiting the Classics to Recover the Physical Sense in Electrical Noise  [PDF]
Jose-Ignacio Izpura
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.26055
Abstract: This paper shows a physically cogent model for electrical noise in resistors that has been obtained from Thermodynamical reasons. This new model derived from the works of Johnson and Nyquist also agrees with the Quantum model for noisy systems handled by Callen and Welton in 1951, thus unifying these two Physical viewpoints. This new model is a Complex or 2-D noise model based on an Admittance that considers both Fluctuation and Dissipation of electrical energy to excel the Real or 1-D model in use that only considers Dissipation. By the two orthogonal currents linked with a common voltage noise by an Admittance function, the new model is shown in frequency domain. Its use in time domain allows to see the pitfall behind a paradox of Statistical Mechanics about systems considered as energy-conserving and deterministic on the microscale that are dissipative and unpredictable on the macroscale and also shows how to use properly the Fluctuation-Dissipation Theorem.
Parallel Evaluation of a Spatial Traversability Cost Function on GPU for Efficient Path Planning  [PDF]
Stephen Cossell, Jose Guivant
Journal of Intelligent Learning Systems and Applications (JILSA) , 2011, DOI: 10.4236/jilsa.2011.34022
Abstract: A parallel version of the traditional grid based cost-to-go function generation algorithm used in robot path planning is introduced. The process takes advantage of the spatial layout of an occupancy grid by concurrently calculating the next wave front of grid cells usually evaluated sequentially in traditional dynamic programming algorithms. The algorithm offers an order of magnitude increase in run time for highly obstacle dense worst-case environments. Efficient path planning of real world agents can greatly increase their accuracy and responsiveness. The process and theoretical analysis are covered before the results of practical testing are discussed.
On the Absence of Carrier Drift in Two-Terminal Devices and the Origin of Their Lowest Resistance Per Carrier Rk=h/Q2  [PDF]
Jose Ignacio Izpura
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.38100
Abstract: After a criticism on today’s model for electrical noise in resistors, we pass to use a Quantum-compliant model based on the discreteness of electrical charge in a complex Admittance. From this new model we show that carrier drift viewed as charged particle motion in response to an electric field is unlike to occur in bulk regions of Solid-State devices where carriers react as dipoles against this field. The absence of the shot noise that charges drifting in resistors should produce and the evolution of the Phase Noise with the active power existing in the resonators of L-C oscillators, are two effects added in proof for this conduction model without carrier drift where the resistance of any two-terminal device becomes discrete and has a minimum value per carrier that is the Quantum Hall resistance Rk=h/q2 Ω
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