1,434 research outputs found
Distribution of sea-air CO 2 fluxes in the Patagonian Sea: Seasonal, biological and thermal effects
Sea-air CO2 fluxes (FCO2) in the Patagonian Sea (PS) were studied using observations collected in 2000-2006. Based on the PS frontal structures and the thermal and biological contributions to FCO2 we present a regional subdivision between distinct regimes that provide new insights on the processes that control these fluxes. The coastal regime (CR) is a net source of atmospheric CO2 (4.9 x 10-3mol.m-2.d-1) while the open shelf regime (SHR) is a net CO2 sink (-6.0 x 10-3mol.m-2.d-1). The interface between these two regions closely follows the location of along-shore fronts. In addition, based on the nature of the processes that drive the FCO2, the PS is subdivided between northern (NR) and southern (SR) regions. Both, NR and SR are CO2 sinks, but the CO2 uptake is significantly higher in NR (-6.4 x 10-3mol.m-2.d-1) than in SR (-0.5 x 10-3mol.m-2.d-1). The data reveal a strong seasonality in FCO2. The mean CO2 capture throughout the PS in austral spring is -5.8 x 10-3mol.m-2.d-1, reaching values lower than -50 x 10-3mol.m-2.d-1 in NR, while in winter FCO2 is close to equilibrium in SR. The analysis of the biological and thermal effects (BE and TE, respectively) on seasonal pCO2 variability indicates that regions of CO2 emission are dominated by the TE while regions of CO2 uptake are dominated by the BE. Our results indicate that the biological pump is the dominant process determining the sea-air CO2 flux in the PS.Fil: Kahl, LucĂa Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la AtmĂłsfera y los OcĂ©anos; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de HidrografĂa Naval. Departamento OceanografĂa; ArgentinaFil: Bianchi, Alejandro A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la AtmĂłsfera y los OcĂ©anos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de HidrografĂa Naval. Departamento OceanografĂa; ArgentinaFil: Osiroff, Ana Paula. Ministerio de Defensa. Armada Argentina. Servicio de HidrografĂa Naval. Departamento OceanografĂa; ArgentinaFil: Pino, Diana Ruiz. Universite Pierre et Marie Curie; FranciaFil: Piola, Alberto Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la AtmĂłsfera y los OcĂ©anos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de HidrografĂa Naval. Departamento OceanografĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
The role of aliphatic alcohols on the stability of collagen and tropocollagen.
Abstract The role of aliphatic alcohols on the temperatures of the helix-coil (Tii) and of the melting transformation (Ti) for collagen in water solutions was investigated. Alcohols used were CH3OH, C2H5OH, and C3H7OH and the role of chloroethanol was also investigated. The results indicate that on increasing alcohol concentration both Ti and Tii are initially depressed (i.e. the random coil form is favored with respect to both the helical and the crystalline form) the order for increasing alcohol effectiveness being C2H4ClOH g C3H7OH g C2H5OH g CH3OH. In the case of the melting transition a subsequent reincrease of Ti with further increase of alcohol content was observed, and in this region the order for increasing effectiveness for depressing the melting temperature was CH3OH g C2H5OH g C3H7OH. Measurements of the equilibrium degree of swelling for cross-linked collagen membranes indicates that the over-all degree of swelling decreases with increasing alcohol concentration. However, measurements of the selective absorption of the alcohols by the membrane reveal a behavior which can be correlated to the melting behavior; i.e. the absorption goes through a maximum on increasing alcohol content and the order for increasing absorption is C3H7OH g C2H5OH g CH3OH below the maximum and CH3OH g C2H5OH g C3H7OH above the maximum. The depressing effect on Ti and Tii observed in diluted alcohol solutions is attributed to a solvation of the side chain apolar groups which become exposed during the transitions
Towards a phenotype of the amphibious company:an illustrative case from the chemical industry
The paper explores the phenotype of the amphibious company, which is intended as the fittest economic species in today’s hypercompetitive business arenas and hence the most likely to survive and prosper. Four behavioral traits are proposed and discussed as distinctive of amphibious companies: doing different jobs good, diversifying in multiple market arenas, brokering and bridging across business networks and absorbing knowledge from the outside. The paper illustrates these arguments through a paradigmatic case study of an Italian firm operating in the chemical industry, which has been able to survive a challenging crisis by adopting an amphibious behavior.<br
Detection strategies for scalar gravitational waves with interferometers and resonant spheres
We compute the response and the angular pattern function of an interferometer
for a scalar component of gravitational radiation in Brans-Dicke theory. We
examine the problem of detecting a stochastic background of scalar GWs and
compute the scalar overlap reduction function in the correlation between an
interferometer and the monopole mode of a resonant sphere. While the
correlation between two interferometers is maximized taking them as close as
possible, the interferometer-sphere correlation is maximized at a finite value
of f*d, where `f' is the resonance frequency of the sphere and `d' the distance
between the detectors. This defines an optimal resonance frequency of the
sphere as a function of the distance. For the correlation between the Virgo
interferometer located near Pisa and a sphere located in Frascati, near Rome,
we find an optimal resonance frequency f=590 Hz. We also briefly discuss the
difficulties in applying this analysis to the dilaton and moduli fields
predicted by string theory.Comment: 26 pages, Latex, 4 Postscript figures. Various minor improvements,
misprint in eqs. 42, 127, 138 corrected, references adde
From Correlators to Wilson Loops in Chern-Simons Matter Theories
We study n-point correlation functions for chiral primary operators in three
dimensional supersymmetric Chern-Simons matter theories. Our analysis is
carried on in N=2 superspace and covers N=2,3 supersymmetric CFT's, the N=6
ABJM and the N=8 BLG models. In the limit where the positions of adjacent
operators become light-like, we find that the one-loop n-point correlator
divided by its tree level expression coincides with a light-like n-polygon
Wilson loop. Remarkably, the result can be simply expressed as a linear
combination of five dimensional two-mass easy boxes. We manage to evaluate the
integrals analytically and find a vanishing result, in agreement with previous
findings for Wilson loops.Comment: 32 pages, 6 figures, JHEP
MGMT methylation assessed by methyl-BEAMing technique is a prognostic and predictive biomarker in glioblastoma and metastatic colorectal cancer patients
Stringy instanton corrections to N=2 gauge couplings
We discuss a string model where a conformal four-dimensional N=2 gauge theory
receives corrections to its gauge kinetic functions from "stringy" instantons.
These contributions are explicitly evaluated by exploiting the localization
properties of the integral over the stringy instanton moduli space. The model
we consider corresponds to a setup with D7/D3-branes in type I' theory
compactified on T4/Z2 x T2, and possesses a perturbatively computable heterotic
dual. In the heteoric side the corrections to the quadratic gauge couplings are
provided by a 1-loop threshold computation and, under the duality map, match
precisely the first few stringy instanton effects in the type I' setup. This
agreement represents a very non-trivial test of our approach to the exotic
instanton calculus.Comment: 63 pages, 5 figures. V2: final version with minor corrections
published on JHEP05(2010)10
A novel soft tissue prediction methodology for orthognathic surgery based on probabilistic finite element modelling
Repositioning of the maxilla in orthognathic surgery is carried out for functional and aesthetic
purposes. Pre-surgical planning tools can predict 3D facial appearance by computing the
response of the soft tissue to the changes to the underlying skeleton. The clinical use of
commercial prediction software remains controversial, likely due to the deterministic nature
of these computational predictions. A novel probabilistic finite element model (FEM) for the
prediction of postoperative facial soft tissues is proposed in this paper. A probabilistic FEM
was developed and validated on a cohort of eight patients who underwent maxillary repositioning and had pre- and postoperative cone beam computed tomography (CBCT) scans
taken. Firstly, a variables correlation assessed various modelling parameters. Secondly, a
design of experiments (DOE) provided a range of potential outcomes based on uniformly
distributed input parameters, followed by an optimisation. Lastly, the second DOE iteration
provided optimised predictions with a probability range. A range of 3D predictions was
obtained using the probabilistic FEM and validated using reconstructed soft tissue surfaces
from the postoperative CBCT data. The predictions in the nose and upper lip areas accurately include the true postoperative position, whereas the prediction under-estimates the
position of the cheeks and lower lip. A probabilistic FEM has been developed and validated
for the prediction of the facial appearance following orthognathic surgery. This method
shows how inaccuracies in the modelling and uncertainties in executing surgical planning
influence the soft tissue prediction and it provides a range of predictions including a minimum and maximum, which may be helpful for patients in understanding the impact of surgery on the face
Tumor MGMT promoter hypermethylation changes over time limit temozolomide efficacy in a phase II trial for metastatic colorectal cancer
Radiomics and artificial intelligence in prostate cancer: new tools for molecular hybrid imaging and theragnostics
In prostate cancer (PCa), the use of new radiopharmaceuticals has improved the accuracy of diagnosis and staging, refined surveillance strategies, and introduced specific and personalized radioreceptor therapies. Nuclear medicine, therefore, holds great promise for improving the quality of life of PCa patients, through managing and processing a vast amount of molecular imaging data and beyond, using a multi-omics approach and improving patients' risk-stratification for tailored medicine. Artificial intelligence (AI) and radiomics may allow clinicians to improve the overall efficiency and accuracy of using these "big data" in both the diagnostic and theragnostic field: from technical aspects (such as semi-automatization of tumor segmentation, image reconstruction, and interpretation) to clinical outcomes, improving a deeper understanding of the molecular environment of PCa, refining personalized treatment strategies, and increasing the ability to predict the outcome. This systematic review aims to describe the current literature on AI and radiomics applied to molecular imaging of prostate cancer
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