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The Calar Alto Secondary Eclipse study was a program dedicated to observe secondary eclipses in the near-IR of two known close-orbiting exoplanets around K-dwarfs: WASP-10b and Qatar-1b. Such observations reveal hints on the orbital configuration of the system and on the thermal emission of the exoplanet, which allows the study of the brightness temperature of its atmosphere. The observations were performed at the Calar Alto Observatory (Spain). We used the OMEGA2000 instrument (Ks band) at the 3.5m telescope. The data was acquired with the telescope strongly defocused. The differential light curve was corrected from systematic effects using the Principal Component Analysis (PCA) technique. The final light curve was fitted using an occultation model to find the eclipse depth and a possible phase shift by performing a MCMC analysis. The observations have revealed a secondary eclipse of WASP-10b with depth of 0.137%, and a depth of 0.196% for Qatar-1b. The observed phase offset from expected mid-eclipse was of −0.0028 for WASP-10b, and of −0.0079 for Qatar-1b. These measured offsets led to a value for |ecosω| of 0.0044 for the WASP-10b system, leading to a derived eccentricity which was too small to be of any significance. For Qatar-1b, we have derived a |ecosω| of 0.0123, however, this last result needs to be confirmed with more data. The estimated Ks-band brightness temperatures are of 1647 K and 1885 K for WASP-10b and Qatar-1b, respectively. We also found an empirical correlation between the (R′HK) activity index of planet hosts and the Ks-band brightness temperature of exoplanets, considering a small number of systems.
Polymer-clay nanocomposites are compounds in which nanoclay particles are distributed in a polymer matrix. Epoxy-clay nanocomposites have become a very interesting topic among researchers in the past two decades because nanoclays have a positive effect on the mechanical, thermal and especially barrier anticorrosive performance of the polymers. In this study, epoxy-montmorillonite organoclay (OMMT) nanocomposite coatings were prepared and deposited on carbon steel substrates. The coatings were prepared through in situ polymerization and by UV-curing technique. The OMMT was added to epoxy resin at loadings between 0 wt.% and 5 wt.%, the particles of OMMT were dispersed using forced agitation-sonication and deposited on carbon steel coupons. The nanocomposite coatings obtained have been characterized by scanning electron microscopy (SEM), spectroscopy Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and evaluated their corrosion protection effect on cold rolled carbon steel coupons by performing visual analysis. The X-ray analysis showed that exfoliation occurred for the OMMT in the polymer matrix, the SEM analysis showed that OMMT was homogenous dispersed in the polymer matrix and the coatings were uniform. The FTIR analysis showed the characteristic bands of epoxy resin and OMMT in the composite. The results showed that 1 wt.% OMMT coating exhibit better anticorrosive properties than pure epoxy.
Dendrons with a porphyrin core and π-conjugated dendron branches have been synthesized and characterized. The dendrons showed an all trans configuration. Cubic non-linear optical behavior of the styryl and porphyrin-containing dendrimers was tested viaZ-Scan measurements in spin-coated film samples.
Oceanographical processes, such as upwelling, induce variations in nutrient availability in marine ecosystems, and evidence indicates that nutrient input can strongly influence the physiological activities, structure, and dynamics of marine communities. Intertidal organisms have long been considered ideal study units in which to quantify the relationship of physical variations and differential energy allocations in specimens that undergo environmental variations, such as observed with nutrient availability. In habitats with differential nutrient input (upwelling versus non-upwelling), both food availability (algae abundance) and seasonal gonadal and foot weight variations were determined in the keyhole limpet Fissurella crassa. Gonadal weight is used as a measure of reproduction allocation whereas foot weight is an indirect indicator of energy allocation towards survival. RNA:DNA ratio in limpets was used as an indicator of biosynthetic capability. Our results indicate that, in general, algae abundance, muscular foot weight, and gonadal weight were higher in upwelling sites during all seasons studied. The same result was found for RNA:DNA ratios. Energetic allocation in animals that inhabit intertidal upwelling habitats supported a constant allocation towards reproduction and soft tissues. In contrast, animals that inhabit non-upwelling habitats showed important energetic restrictions associated with higher water temperature and lower food availability. Our results clearly show that in the keyhole limpet F. crassa food availability is a more important determinant of an individual's condition than a physical variation such as environment temperature.
Intertidal organisms have long been considered an ideal system to quantify how physical variations determine differential energy allocations in specimens inhabiting environmental gradients such as exposure to wave action. In habitats with differential intertidal wave exposure (sheltered, Sh; and exposed, E) seasonal gonadal and foot weight variations and their associations with exposure and food availability (algae abundance) were determined in the keyhole limpet Fissurella crassa. Gonadal weight is used as a measure of reproduction allocation whereas foot weight is an indirect indicator of energy allocation to survival. RNA:DNA ratio in limpets obtained from Sh and E habitats during the two different seasons was used as an indicator of biosynthetic capability. Our results indicate that algae abundance in E sites was higher in summer and lower in winter compared to Sh sites. In E sites the muscular foot weight of limpet was higher in summer in contrast to Sh sites where F. crassa muscular foot weight of limpet was higher in winter. Gonadal weight in Sh sites was higher in summer and remained constant in winter; whereas in E sites gonadal weight was lower in summer and higher in winter. RNA:DNA ratios indicate that regardless of intertidal wave exposure, F. crassa showed higher biosynthetic capability in summer. Energetic allocation in animals that inhabit sheltered intertidal habitats would support constant allocation towards reproduction. In contrast, animals that inhabit exposed habitats may favour seasonally reproduction allocation at expense of survival.
Development of sustainable agricultural production systems in the tropics is challenging in part because the local and external conditions that affect sustainability are constantly in flux. The Quesungual agroforestry system (QSMAS) was developed in response to these changing conditions. The history and potential future of the QSMAS provide an opportunity to consider the factors affecting small-scale agricultural production systems on marginal lands throughout the world. We evaluated the QSMAS in Honduras in the context of the five principles of the Drylands Development Paradigm (DDP) during three periods: pre-QSMAS, QSMAS adoption and the future. The first two periods provided lessons that could be relevant to other regions. The QSMAS system in Honduras must continue to evolve, if long-term benefits are to be realized. We conclude that while the DDP was a useful framework for systematically identifying the critical drivers and processes determining the sustainability of QSMAS in Honduras, it is ultimately no more able to predict the future than the collective knowledge of those who choose to apply it. The DDP, however, can facilitate the integration and application of knowledge.
Despite the important role that total factor productivity (TFP) has played in the growth literature, few attempts have been made to change the methodology to estimate it. This paper proposes a methodology based on a state-space model to estimate TFP and its determinants. With this methodology, it is possible to reduce the measurement of our ignorance. As a by-product, this estimate yields the capital share in output and the long-term growth rate. When applied to Chile, the estimation shows a capital share around 0.5 and long-term growth of TFP around 1%. Capital accumulation tends to explain the growth rate in the fast growth periods under the econometric estimation more than the traditional growth accounting methodology.
During a parasitological survey of the brown mussel Perna perna from highly productive culture fields in the southern sector of Brazil, monstrilloid copepods were discovered in the mantle of this mytilid bivalve. Numerous specimens of endoparasitic copepods were found within nodules in the mantle of the host; they belong to an undetermined species of Monstrilla. Monstrilloid copepods were known to be endoparasitic in polychaetes and in one species of prosobranch mollusc only; their occurrence as parasites of bivalve molluscs has not been previously documented. This is also the first record of these crustaceans infecting commercial molluscs. The prevalence of Monstrilla sp. infecting the brown mussel was 25.6%. At the histological level, it was observed that the larvae induced a strong haemocytic infiltration resulting from the complete larval encapsulation within the host mantle. The effect of this monstrilloid in the cultured populations of P. perna deserves further study.
Although sexual harassment has been extensively studied, empirical research has not led to firm conclusions about its antecedents and consequences, both at the personal and organizational level. An extensive literature search yielded 42 empirical studies with 60 samples. The matrix correlation obtained through meta-analytic techniques was used totest a structural equation model. Results supported the hypotheses regarding organizational environmental factors as main predictors of harassment.
Empirical analyses of annuities markets have been limited to a few developed countries and restricted by data limitations. Chile provides excellent conditions for research on annuities due to the depth of its market and the availability of data. The paper utilizes a panel of life insurance company data to examine econometrically the main determinants of the annuity rate, defined as the internal rate of return on annuities. The results indicate that the annuity rate is determined by the risk-free interest rate, the share of privately issued higher yield securities in the portfolio of providers, as a proxy for the spread over the risk-free rate, the leverage of providers, the level of broker's commissions, the market share of individual providers, the level of the premium, and the degree of market competition. The results also show that efforts to improve market transparency produced structural shifts in the parameters of the annuity rate equation. The results are consistent with separate research on money's worth ratios, and indicate the need to develop appropriate financial instruments, allowing providers to hedge their risks while extracting higher returns, and also to ensure competition and transparency in annuities markets, in order to ensure good outcomes for annuitants.
Empirical analyses of annuities markets have been limited to a few developed countries and restricted by data limitations. Chile provides excellent conditions for research on annuities due to the depth of its market and the availability of data. The paper utilizes an extensive dataset on individual annuities to examine econometrically a measure of market performance – money's worth ratios (MWRs), or the ratio of the expected present value of annuity payments to the premium. The results show that annuitants in Chile have generally got a good deal for their premiums, as indicated by MWRs higher than one and also higher than those estimated for other countries. The difference between Chile and other countries is striking considering that annuities in Chile are indexed to prices. The wide range of indexed instruments in Chile, allowing providers to hedge their risks while extracting higher returns, helps explain the difference. The high degree of market competition has also contributed to this outcome. Efforts to improve market transparency through a new electronic quotation system have decreased the dispersion of MWRs. Finally, MWRs tend to decrease for contracts with longer durations, reflecting pricing for higher longevity and reinvestment risks. These results are consistent with separate research on the annuity rate, and indicate the need to ensure competition and market transparency, as well as to develop appropriate financial instruments for providers in order to ensure good outcomes for annuitants.
The effectiveness of association mapping (AM) based on linkage disequilibrium (LD) is currently being tested in a number of crops. An important prerequisite for the application of AM is the availability of collections of accessions with a suitable level of genetic variation for target traits and with limited spurious LD due to the presence of population structure. Herein, the results of a genome-wide molecular characterization of a collection of elite durum wheat accessions well-adapted to Mediterranean environments are presented. Ninety-seven highly polymorphic simple sequence repeats and 166 amplified fragment length polymorphism markers were used to characterize 189 durum accessions, mainly cultivars and advanced breeding lines. Genome-wide significant and sizeable LD indices at a centimorgan scale were observed, while LD mainly decayed within 10 cM. On the other hand, effects due to spurious LD were notably lower than those previously observed in a durum wheat collection sampling durum gene pools of more diverse origin. These results, coupled with the high level of genetic variability detected for a number of important morpho-physiological traits and their high heritability, indicate the suitability of this collection for AM studies targeting agronomically important traits.
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