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The IUPAC–IUGS joint Task Group “Isotopes in Geosciences” (TGIG) has evaluated the published literature on the half-lives of six long-lived, geologically relevant radioactive nuclides. Where conflicting literature estimates are present, it is necessary to first identify any systematic bias in accordance with metrological traceability and to exclude the biased estimates from further consideration. The TGIG recommends three robust half-life estimates: 49.61 ± 0.16 Ga for 87Rb, corresponding to a decay constant λ(87Rb) = (1.3972 ± 0.0045) × 10−11 a−1; 106.25 ± 0.38 Ga for 147Sm, and a corresponding decay constant λ(147Sm) = (6.524 ± 0.024) × 10−12 a−1; 4.4683 ± 0.0096 Ga for 238U, i.e. a decay constant λ(238U) = (1.55125 ± 0.00333) × 10−10 a−1. All cited uncertainties have a coverage factor k = 2. For other radionuclides of Sm and U, no unambiguous consensus value can be endorsed at present by TGIG, which limits its evaluation to a status report highlighting unaccounted-for potential sources of bias. The improved repeatability of mass spectrometric measurements has revealed systematic bias effects that had been dismissed as subordinate in the past. These issues can only be resolved by future dedicated investigations.

In this paper, we study the long-time dynamics of a Timoshenko system modeling vibrations of beams with non-linear localized damping mechanisms acting on both displacement and angular rotation and subjected to non-linear source terms. Using recent quasi-stability methods, we prove the existence of smooth finite dimensional global attractor, which is characterized as unstable manifold of the set of stationary solutions. Moreover, the existence of exponential attractors is shown. These aspects were not previously considered for the Timoshenko system with localized damping.

The objective of the present study was to evaluate the effect of anthropometric variables and flexibility on the performance of women aged 55+ years on abdominal test protocols. The sample was composed by 20 physically active volunteers, aged 55 years (median 61), who were participants in gymnastic activities program. Each volunteer performed two abdominal tests: partial trunk flexion with a 7.6 cm sliding of the hands (P1) and partial flexion of the trunk with the hands on the thighs (P2), both executed with the feet resting on the ground. For analysis, the number of correct executions (final position) was considered in each test, as recommended by the authors. Measurements of body mass, flexibility, height, waist and hip perimeters, subjective perception of exertion, and calculations of body mass index and waist-hip ratio were performed. The perception of abdominal effort, and discomfort or pain in the cervical and lumbar region were also evaluated. The results showed that there were no statistically significant associations between the analyzed indicators (Age: P1: rs = -0.024, p = 0.916; P2: rs = -0.194, p = 0.407; BMI: P1: rs =-0.064, p = 0.792; P2: rs = -0.235, p= 0.327; Waist Circumference: P1: rs = -0.143, p = 0.563; P2: rs = 0.027, p = 0.908; Flexibility: r s= -0.327, p = 0.169; P2: rs = 0.0009, p = 0.991; Hip waist ratio: P1: rs = -0.209, p = 0.371; P2: rs = 0.217, p = 0.353) and the performance on the tests. In addition, 35% of the participants made valid attempts on P1 while 45% produced at least one valid attempt on P2. It was concluded that both abdominal tests were adequate for the studied sample and they can be applied to adult and elderly women to assess their abdominal musculature.

Thais RD Paini,1 Joana YT Uchimura,1 Francielle Sato,2 Antonio Medina Neto,2 Eliana LT Shimauti,3 Mauro L Baesso,2 Mirian M Hidalgo,1 Marcia LA dos Santos,4 Isolde TS Previdelli,4 Renata C Pascotto1 1Department of Dentistry, State University of Maringa, Maringá, PR, Brazil; 2Department of Physics, State University of Maringa, Maringá, PR, Brazil; 3Department of Clinical Analysis and Biomedical Science, State University of Maringa, Maringá, PR, Brazil; 4Department of Statistics, State University of Maringa, Maringá, PR, BrazilCorrespondence: Renata C Pascotto, Department of Dentistry, State University of Maringa, Av. Mandacaru 1.550, Maringá, PR, 87080-000, Brazil, Tel +55 44 99820215, Fax +55 44 30319051, Email renatapascotto@gmail.comBackground: The use of discolored teeth is required to test whitening products, and it is difficult to obtain them, given their scarcity.Objective: To present a technique for in vitro darkening of extracted teeth simulating pulpal necrosis discoloration.Materials and Methods: Hemolysates I and II from human blood were subjected or not to laser irradiation (442 nm) for 1 h. The concentration of oxyhemoglobin (O2Hb) was analyzed by ultraviolet/visible spectroscopy, and the conversion of O2Hb to methemoglobin (MetHb) by transmission spectroscopy was assessed immediately and after 3 and 40 days. For darkening evaluation, bovine incisors were divided into two groups (n = 25), and their pulp chambers were filled with hemolysate solution II (HSII) and hemolysate II solution + laser (HSII+L). After storage in artificial saliva for 40 days at 37°C, color changes were measured by a colorimeter and ΔE was compared with the NBS parameters. Data were analyzed using a mixed linear model (α=5%).Results: HSII+L presented the lowest O2Hb and higher MetHb. The conversion of O2Hb to MetHb in HSII+L was 42% higher than in HSII. Both groups were effective in darkening the teeth, according to the NBS. Darkening stabilized from day 35. HSII promoted a marked color difference.Conclusion: The proposed technique was effective in darkening the extracted teeth simulating necrosis discoloration for in vitro models.Graphical Abstract: Keywords: teeth, blood, colorimetry, hemoglobin, spectroscopy

The preponderance of Intrinsically Disordered Proteins (IDPs) in the eukaryotic proteome, and their ability to interact with each other, proteins, RNA, and DNA for functional purposes have made it important to quantitatively characterize their biophysical properties. Towards this end, we developed the transferable Self-Organized Polymer (SOP-IDP) model in order to calculate the properties of a number of IDPs. The calculated and measured radius of gyration values (Rgs) are in excellent agreement, with a correlation coefficient of 0.96. For AP180 and Epsin, the predicted and values obtained using Fluorescence Correlation Spectroscopy for the hydrodynamic radii (Rhs) are also in quantitative agreement. Strikingly, the calculated SAXS profiles for thirty six IDPs also nearly match the experiments. The dependence ofRg, the mean end-to-end distance (Re), andRhobey the Flory scaling law,Rα≈aαN0.59(α=g, e, andh), suggesting that globally IDPs behave as polymers in a good solvent. The values ofag,ae, andahare 0.21 nm, 0.53 nm, and 0.16 nm, respectively. Surprisingly, finite size corrections to scaling, expected on theoretical grounds, for all the three quantities are negligible. Sequence dependencies, masked in ensemble properties, emerge through a fine structure analyses of the conformational ensembles using a hierarchical clustering method. Typically, the ensemble of conformations partition into three distinct clusters, with differing extent of population and structural properties. The subpopulations could dictate phase separation tendencies and association with ligands. Without any adjustments to the three parameters in the SOP-IDP model, we obtained excellent agreement with paramagnetic relaxation enhancement (PRE) measurements forα-synuclein. The transferable SOP-IDP model sets the stage for a number of promising applications, including the study of phase separation in IDPs and interactions with nucleic acids.

This paper is devoted to study the asymptotic behavior of a binary mixture problem of solids with fractional damping and sources terms. We prove the existence of global attractors with finite fractal dimension and the existence of exponential attractors. Moreover, we prove the upper-semicontinuity of global attractors as the fractional exponent tend to zero.

We develop a theory to probe the effect of nonequilibrium fluctuation-induced forces on the size of a polymer confined between two horizontal, thermally conductive plates subject to a constant temperature gradient, ∇ T. We assume that (a) the solvent is good and (b) the distance between the plates is large so that in the absence of a thermal gradient the polymer is a coil, whose size scales with the number of monomers as Nν, with ν ≈ 0.6. We find that above a critical temperature gradient, ∇ Tc ≈ N-5/4, a favorable attractive monomer-monomer interaction due to the giant Casimir force (GCF) overcomes the chain conformational entropy, resulting in a coil-globule transition. Our predictions can be verified using light-scattering experiments with polymers, such as polystyrene or polyisoprene in organic solvents in which the GCF is attractive.

We present a theoretical method to study how changes in pH shape the heterogeneous conformational ensemble explored by intrinsically disordered proteins (IDPs). The theory is developed in the context of coarse-grained models, which enable a fast, accurate, and extensive exploration of conformational space at a given protonation state. In order to account for pH effects, we generalize the Molecular Transfer Model (MTM), in which conformations are re-weighted using the transfer free energy, which is the free energy necessary for bringing to equilibrium in a new environment a “frozen” conformation of the system. Using the semi-grand ensemble, we derive an exact expression of the transfer free energy, which amounts to the appropriate summation over all the protonation states. Because the exact result is computationally too demanding to be useful for large polyelectrolytes or IDPs, we introduce a mean-field (MF) approximation of the transfer free energy. Using a lattice model, we compare the exact and MF results for the transfer free energy and a variety of observables associated with the model IDP. We find that the precise location of the charged groups (the sequence), and not merely the net charge, determines the structural properties. We demonstrate that some of the limitations previously noted for MF theory in the context of globular proteins are mitigated when disordered polymers are studied. The excellent agreement between the exact and MF results poises us to use the method presented here as a computational tool to study the properties of IDPs and other biological systems as a function of pH.

Substantial increase in the temporal resolution of the stepping of dimeric molec- ular motors is possible by tracking the position of a large gold nanoparticle (GNP) attached to a labeled site on one of the heads. This technique was used to measure the stepping trajectories of conventional kinesin (Kin1) using the time dependent position of the GNP as a proxy. The trajectories revealed that the detached head always passes to the right of the head that is tightly bound to the microtubule (MT) during a step. In interpreting the results of such experiments, it is implicitly assumed that the GNP does not significantly alter the diffusive motion of the detached head. We used coarse-grained simulations of a system consisting of the MT-Kin1 complex with and without attached GNP to investigate how the stepping trajectories are affected. The two significant findings are: (1) The GNP does not faithfully track the position of the stepping head. (2) The rightward bias is typically exaggerated by the GNP. Both these findings depend on the precise residue position to which the GNP is attached. Surprisingly, we predict that the stepping trajectories of kinesin are not significantly affected if, in addition to the GNP, a 1 μm diameter cargo is attached to the coiled coil. Our simulations suggest the effects of the large probe have to be considered when inferring the stepping mechanisms using GNP tracking experiments.

Reconstructing coral reef histories provides a window of understanding into reef response to changing environmental and climatic conditions over various temporal scales. Here we present the results of 117 U-Th dates from emergent reef flat and slope cores and surface death assemblages, combined with previously published fossil microatoll data, to capture the entire sequence of reef growth at Mazie Bay, inshore Southern Great Barrier Reef (GBR). Coral U-Th dates indicate that Mazie Bay reef initiated ~6,900 years before present (yr. BP) quickly filling accommodation space. While rates of vertical reef accretion (5.3 ± 1.0 mm year⁻¹) were comparable to the GBR average during the mid-Holocene (~5.0 mm year⁻¹), reef flat progradation occurred at a rate 1.5- to 6-fold previous GBR rates until 5,100 yr. BP (~70.4 cm year⁻¹). Average progradation slowed to ~7.1 cm year⁻¹ in the subsequent ~4,000 years and reef slope cores indicate this reef had largely "turned-off" by 400 yr. BP, with modern coral communities existing as a veneer over the largely senescent framework. Death assemblage dates highlight coral disturbance and recovery regimes in response to increased cyclone activity 1960-1985 AD and recent extreme sea surface temperature and flood events post 2000 AD. U-Th dating of mid-Holocene to modern coral deposits from Mazie Bay reef provides a unique insight into past reef development, response to recent disturbance regimes, and potential for future reef growth. In the case of Mazie Bay, our data suggest limited accommodation space and increased occurrence of sea surface temperature extremes will restrict future reef growth at this site.

In this paper, we study the long-time dynamics of a system modelinga mixture of three interacting continua with nonlinear damping, sources terms and subjected to small perturbations of autonomousexternal forces with a parameter \begin{document}$ \epsilon $\end{document}, inspired by the modelstudied by Dell' Oro and Rivera [12]. We establish astabilizability estimate for the associated gradient dynamicalsystem, which as a consequence, implies the existence of a compactglobal attractor with finite fractal dimension andexponential attractors. This estimate is establishedindependent of the parameter \begin{document}$ \epsilon\in[0,1] $\end{document}. We also prove thesmoothness of global attractors independent of the parameter\begin{document}$ \epsilon\in[0,1] $\end{document}. Moreover, we show that the family of globalattractors is continuous with respect to the parameter \begin{document}$ \epsilon $\end{document} ona residual dense set \begin{document}$ I_*\subset[0,1] $\end{document} in the same sense proposed inHoang et al. [15].

We investigate the chemical reactivity of molecular populations confined inside a nanofluidic Fabry-P{��}rot cavity. Due to strong light-matter interactions developing between a resonant electromagnetic cavity-mode and the electric dipole moment of the confined molecules, a polariton is formed. The former gets dressed by environmental vibrational and rotational degrees of freedom of the solvent. We call the resulting polariton dressed by its cloud of environmental excitation a ''reacton'', since it further undergoes chemical reactions. We characterize how the reacton formation modifies the kinetics of a photoisomerization chemical reaction involving an elementary charge-transfer process. We show that the reaction driving-force and reorganization energy are both modulated optically by the reactant concentration, the vacuum Rabi splitting and the de-tuning between the Fabry-P{��}rot cavity frequency and targeted electronic transition. Finally, we compute the ultrafast picosecond dynamics of the whole photochemical reaction. We predict that despite optical cavity losses and solvent-mediated non-radiative relaxation, measurable signatures of the reacton formation can be found in state-of-the-art pump-probe experiments.

From the Editors

Molecular motors, such as myosin, kinesin, and dynein, convert the energy released by the hydrolysis of ATP into mechanical work, which allows them to undergo directional motion on cytoskeletal tracks. This process is achieved through synchronization between the catalytic activity of the motor and the associated changes in its conformation. A pivotal step in the chemomechanical transduction in myosin motors occurs after they bind to the actin filament, which triggers the release of phosphate (Pi, product of ATP hydrolysis) and the rotation of the lever arm. Here, we investigate the mechanism of phosphate release in myosin VI, which has been debated for over two decades, using extensive molecular dynamics simulations involving multiple trajectories each severalμslong. Because the escape of phosphate is expected to occur on time-scales on the order of milliseconds in myosin VI, we observed Pirelease only if the trajectories were initiated with a rotated phosphate inside the nucleotide binding pocket. The rotation provided the needed perturbation that enabled successful expulsions of Piin several trajectories. Analyses of these trajectories lead to a robust mechanism of Pirelease in the class of motors belonging to the myosin super family. We discovered that although Pipopulates the traditional “back door” route, phosphate exits through various other gateways, thus establishing the heterogeneity in the escape routes. Remarkably, we observe that the release of phosphate is preceded by a step-wise hydration of the ADP-bound magnesium ion. In particular, the release of the anion occurredonly after four water moleculeshydrate the cation (Mg2+). By performing comparative structural analyses, we suggest that the hydration of magnesium is the key step in the phosphate release in a number of ATPases and GTPases that share a similar structure in the nucleotide binding pocket. Thus, nature may have evolved hydration of Mg2+by discrete water molecules as a general molecular switch for Pirelease, which is a universal step in the catalytic cycle of many machines which share little sequence or structural similarity.

The present contribution involves deposits of continental Neogene age that outcrop in the Bahia Blanca region. The studies that were carried out in order to contribute to the paleoenvironmental and chronostratigraphical knowledge involve sedimentological, paleomagnetic and magnetic susceptibility analyses. One of the outcrops studied (Cueva de Los Leones) is mainly composed of facies of fine to thick sandstones, largely pedogenized and with important amounts of calcrete, whereas the other (Loma Sarmiento) has a predominance of loess-like silt facies, reddish brown in colour, an abundance of rhizoconcretions and evidence of pedogenic processes. Both outcrops culminate in an important layer of calcrete of regional scope, with particular morphologies at each of the sites. The paleomagnetic analysis leads to the conclusion that the sedimentation of the deposits underlying the calcareous crust at the two sites was not synchronous. Reverse polarity was recorded in the Cueva de Los Leones in contrast to Loma Sarmiento, where normal polarity is predominant. The paleomagnetic samples of calcareous crust on the top presented anomalous polarity directions in both sections, with very high values of magnetic intensity. The reverse directions in the Cueva de Los Leones can be assigned to the Gilbert Cron (6.0–3.6 Ma), without discarding younger ages in the Pliocene. In contrast, Loma Sarmiento seems to be older (Late Miocene). The susceptibility records also indicated differences between the two sites that would be linked to pedogenic development; they were higher in Loma Sarmiento and judging by the F% factor, in Cueva de los Leones the superparamagnetic particles contribution is higher. Petrographic, X-Ray difractometry, paleontological and soil micromorphology analyses, in some places at the studied sites, also contributed to the paleoenvironmental/paleoclimatic reconstruction carried out.

From the EditorSpecial Issue – Women in Sciences: Historiography of Science and History of Science – on the Work of Women in Sciences and Philosophy

Processive molecular motors enable cargo transportation by assembling into dimers capable of taking several consecutive steps along a cytoskeletal filament. In the well-accepted hand-over-hand stepping mechanism, the trailing motor detaches from the track and binds the filament again in the leading position. This requires fuel consumption in the form of ATP hydrolysis and coordination of the catalytic cycles between the leading and the trailing heads. Alternate stepping pathways also exist, including inchworm-like movements, backward steps, and foot stomps. Whether all the pathways are coupled to ATP hydrolysis remains to be determined. Here, to establish the principles governing the dynamics of processive movement, we present a theoretical framework that includes all of the alternative stepping mechanisms. Our theory bridges the gap between the elemental rates describing the biochemical and structural transitions in each head and the experimentally measurable quantities such as velocity, processivity, and probability of backward stepping. Our results, obtained under the assumption that the track is periodic and infinite, provide expressions that hold regardless of the topology of the network connecting the intermediate states, and are therefore capable of describing the function of any molecular motor. We apply the theory to myosin VI, a motor that takes frequent backward steps and moves forward with a combination of hand-over-hand and inchworm-like steps. Our model quantitatively reproduces various observables of myosin VI motility reported by four experimental groups. The theory is used to predict the gating mechanism, the pathway for backward stepping, and the energy consumption as a function of ATP concentration.

Block-based transceivers are widely used in wireless communication systems, mostly due to their well-defined structure and blockwise encoding. Interblock interference caused by superpositions of delayed signal copies is among their main physical-layer challenges, which is commonly eliminated with redundancy between adjacent data-blocks. Besides, channel equalization is also employed to further mitigate multipath channel interferences. The chosen amount of redundancy, however, may be overestimated, which opens an opportunity for reduced-redundancy superfast transceivers, whose key features include high spectral efficiency and low computational cost. Although superfast approaches aim at low complexity, proper equalizer-coefficient design and update procedures are still very intricate tasks, and most approaches are rather computationally cumbersome. This paper addresses such problem by proposing a new design strategy for reduced-redundancy block-based transceivers, which provides semi-blind equalization with data-selective update, in addition to the possibility of using redundant parallel equalizer structures, which are based on the use of fast Fourier transforms and one-tap equalizers. Simulation results indicate that the proposed methodology is effective and also able to achieve a performance comparable to what is obtained with state-of-the-art techniques, depending on the target application.

This paper is concerned with the study on the existence of attractors for a nonlinear porous elastic system subjected to a delay-type damping in the volume fraction equation. The study will be performed, from the point of view of quasi-stability for infinite dimensional dynamical systems and from then on we will have the result of the existence of global and exponential attractors.

In the face of changing global climate the future of corals reefs is uncertain. High latitude reefs may offer potential refugia for corals under projected increasing sea surface temperatures (SSTs). To understand the reef growth potential of modern high latitude reefs it is first necessary to understand past reef growth and response to climatic and environmental changes. The history of the Great Barrier Reef (GBR) has been shown to be punctuated by a multi-millennial Mid-Holocene reef “turn-off” or initiation hiatus in the Northern and Southern GBR (∼5500–2500 years before present [yr. BP]). Here we present the results of chronologically constrained reef matrix cores from five continental island fringing reefs and coral communities in the Keppel Islands to revaluate the timing, extent and possible drivers of the Mid-Holocene hiatus in the Southern GBR. Earliest initiation occurred at Wedge and Halfway Islands at 7773 ± 19 yr. BP and 7455 ± 20 yr. BP, respectively. Following initiation, vertical reef accretion at Halfway was comparable to previously reported rates for the GBR of ∼3.4 mm yr−1, increasing to ∼8.0 mm yr−1 between 6100 and 5500 yr. BP. Conversely, the coral community at Wedge Island, located closer to mainland terrestrial influence, accreted

Interview: Regina Horta Duarte

BACKGROUND Activities in the aquatic environment can be an interesting alternative of physical exercise for the elderly, due to several properties of water, which can favor the physiological, metabolic, perceptive, and musculoskeletal effects. The aim of this study was to compare the effects of performing two hydrogymnastic class methodologies on the functional capacity and flexibility in elderly women. METHODS Ninety women, aged 55-70 years, were divided into three groups, the control group (CG; N.=30) who did not exercise during the 12 weeks, experimental group 1 (EG1; N.=30), who performed water gymnastics classes with emphasis on lower limb exercises for 12 weeks, and experimental group 2 (EG2; N.=30), who performed conventional hydrogymnastics classes for 12 weeks. The volunteers were evaluated through the 30-second chair stand (30CST), 2-minute step test (2MST), timed up and go (TUG), static balance (SB) and chair sit-and-reach (CSR) tests. RESULTS In the intragroup comparison, there were significant improvements in the performance of 30CST tests (F=5.5, P=0.022), TUG (F=19.3, P

1SummaryCytoplasmic Dynein, a motor with an unusual architecture made up of a motor domain belonging to the AAA+ family, walks on microtubule towards the minus end. Prompted by the availability of structures in different nucleotide states, we performed simulations based on a new coarse-grained model to illustrate the molecular details of the dynamics of allosteric transitions in the motor. The simulations show that binding of ATP results in the closure of the cleft between the AAA1 and AAA2, which in turn triggers conformational changes in the rest of the motor domain, thus poising dynein in the pre-power stroke state. Interactions with the microtubule, which are modeled implicitly, substantially enhances the rate of ADP release, and formation of the post-power stroke state. The dynamics associated with the key mechanical element, the linker (LN) domain, which changes from a straight to a bent state and vice versa, are highly heterogeneous suggestive of multiple routes in the pre power stroke to post power stroke transition. We show that persistent interactions between the LN and the insert loops in the AAA2 domain prevent the formation of pre-power stroke state when ATP is bound to AAA3, thus locking dynein in a non-functional repressed state. Motility in such a state may be rescued by applying mechanical force to the LN domain. Taken together, these results show how the intricate signaling dynamics within the motor domain facilitate the stepping of dynein.

This paper presents a simple agent-based model of an economic system, populated by agents playing different games according to their different view about social cohesion and tax payment. After a first set of simulations, correctly replicating results of existing literature, a wider analysis is presented in order to study the effects of a dynamic-adaptation rule, in which citizens may possibly decide to modify their individual tax compliance according to individual criteria, such as, the strength of their ethical commitment, the satisfaction gained by consumption of the public good and the perceived opinion of neighbors. Results show the presence of thresholds levels in the composition of society - between taxpayers and evaders - which explain the extent of damages deriving from tax evasion., Comment: 19 pages, 11 figures

This study examines the influence of Koyre’s philosophy of mathematics on his later history of science. This chapter focuses on a topic that has been almost unexamined by Koyre’s commentators, his first papers on the foundations of mathematics (which present his criticism of Bertrand Russell’s paradox), to establish a link between Koyre’s mathematical realism – present in his preoccupation with the foundations of mathematics – and his later history of science. Based on this link, I reassess an old controversy: “the philosophers and the machine”, as it is called by Koyre, or the problem of theoria versus praxis. Finally, I attempt to understand the extent to which Koyre’s internalism, which originates in this controversy, continues to raise important issues, such as the autonomy of science, in the face of sociological interpretations of science.

Editorial of Transversal: International Journal for the Historiography of Science issue 2 (June 2017).

En 2013, la progression du patrimoine économique national est soutenue par celle du patrimoine financier des ménages alors même que les sociétés non financières réduisent leurs stocks. Les ménages limitent la croissance des crédits contractés et renforcent leurs souscriptions nettes en contrats d’assurance-vie ; ils délaissent les obligations et les titres d’OPC et réduisent leurs placements sur les livrets d’épargne.

Specimens of Apteronotus brasiliensis from Paraná and São Francisco River basins (Brazil) present snout always moderately elongated, that can be oblique or directed forward or strongly downward. Detailed examination revealed that these head-morphology differences are related to individual variation, not to sex, ontogeny or geographic distribution.

The solubility of citric acid or 3-carboxy-3-hydroxypentanedioic acid in water, ethanol, n-propanol and ethanol + water mixtures at temperatures ranging from 293.7 to 333.1 K was investigated. The experimental results obtained were correlated with the temperature for pure solvents by two equations based on the literature. For ternary systems, data were correlated as function of alcohol concentration for each temperature. Regarding the pure solvents, both of the models demonstrated good agreement with the experimental data. There are disagreements with the recent work published by Daneshfar et al. (2012) [12] . It was observed that adding ethanol in the water increased citric acid solubility in all cases.