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Angiopoietin-like 3 (ANGPTL3) plays an important role in lipid metabolism in humans. Loss-of-function variants in ANGPTL3 cause a monogenic disease named familial combined hypolipidemia. However, the potential contribution of ANGPTL3 gene in subjects with familial combined hyperlipidemia (FCHL) has not been studied. For that reason, the aim of this work was to investigate the potential contribution of ANGPTL3 in the aetiology of FCHL by identifying gain-of-function (GOF) genetic variants in the ANGPTL3 gene in FCHL subjects. ANGPTL3 gene was sequenced in 162 unrelated subjects with severe FCHL and 165 normolipemic controls. Pathogenicity of genetic variants was predicted with PredictSNP2 and FruitFly. Frequency of identified variants in FCHL was compared with that of normolipemic controls and that described in the 1000 Genomes Project. No GOF mutations in ANGPTL3 were present in subjects with FCHL. Four variants were identified in FCHL subjects, showing a different frequency from that observed in normolipemic controls: c.607-109T>C, c.607-47_607-46delGT, c.835+41C>A and c.*52_*60del. This last variant, c.*52_*60del, is a microRNA associated sequence in the 3′UTR of ANGPTL3, and it was present 2.7 times more frequently in normolipemic controls than in FCHL subjects. Our research shows that no GOF mutations in ANGPTL3 were found in a large group of unrelated subjects with FCHL. [ABSTRACT FROM AUTHOR]

Colombia, like other developing countries has been incorporating different electrical vehicles to the automotive national market. While the acquisition of a brand new electric vehicle is still expensive, transformation from used traditional vehicles (combustion) to electrical vehicles has become an interesting economical option. This work presents a performance evaluation of a transformed vehicle from its combustion version. The theoretical and experimental analysis (in rugged geographical reliefs such as Colombia) are necessary to consolidate the validity of this type of proposals at technical, economic and environmental impact levels. The procedure of an electric conversion presented herein showed significant mitigation of greenhouse gases owing to the renunciation of 6,54 L per 100 km and hence avoiding CO emissions: 1,808 g/km and THC + NOx: 0,652 g/km. The procedure included selection of both suitable car (low weight) and electric conversion kit, as well as assembly design, disassembly of combustion system, implementation of electric components. Additionally, experimental tests were performed to determine the behavior with respect to power under some load demands validating the proposed traction model. [ABSTRACT FROM AUTHOR]

The present research project focuses on the development of a Savonius type wind turbine, where a literature review is initially carried out to recognize the appropriate parameters for its design such as turbulence, wind velocity, and air density, followed by a design methodology to achieve the dimensioning by means of resistance calculation and selection of component materials, after having the final concept defined. Through the use of computational tools such as Solidworks, Inventor, Simulation Mechanical, the design stage was validated through simulation to study the dynamic fluid behavior and the components were modeled to evaluate their response to wind loads, verifying their resistance. Subsequently, according to the modeling, the detailed drawings of the components of the turbine were obtained, with which they were assembled. Finally, having the physical model of the Savonius wind turbine, experimental tests were carried out in the laboratory of Fluids and Hydraulic Machines of the Technological University of Pereira. As an important result of analysis (simulation and experimental tests) a power coefficient of 0,2 was obtained and shaft mechanical power varies with cubic velocity wind. Power over 100 W can be reached with sweep area 1 m2 and 10 m/s velocity turbines. [ABSTRACT FROM AUTHOR]

In this work we study the influence of the thiourea/CdCl2 concentration ratio used for the chemical bath deposition of CdS thin films on glass substrates, upon the CdS/CdTe interface recombination velocity in CdTe/CdS/glass structures, where the CdTe layer was grown on the CdS thin film by close space vapor deposition (CSVT)-hot wall technique. The interface recombination velocity was measured by means of the photoacoustic (PA) technique in a heat transmission configuration, in which minority carriers are photoexcited at the CdTe layer after illumination through the substrate and the CdS thin film. For data processing, a theoretical model was developed for the generation of the PA signal. We show a reduction in the value of the recombination velocity respecting those obtained for samples where CdS was grown by CSVT, and we observe that a minimal value appears for a thiourea/CdCl2 ratio in the CdS deposition solution equal to 5. These results show a good correlation with those of electrical measurements performed in solar cell devices. [ABSTRACT FROM AUTHOR]

A method is proposed to measure the in-plane thermal diffusivity of anisotropic solids along an arbitrary direction using laser-line lock-in thermography. In this method, the sample is heated by an intensity-modulated laser beam, which impinges on the sample surface with the shape of a narrow strip. The resulting temperature oscillations are recorded by a thermographic camera and a phase thermogram is obtained by lock-in processing the image sequence. The thermal diffusivity along the direction perpendicular to the laser line can be determined from the linear dependence of phase lag with the distance to the heating line using the slope method. Unlike laser-spot lock-in thermography, in which the slope method only provides the thermal diffusivity along the principal directions, in this configuration, the thermal diffusivity can be measured experimentally along any direction, just selecting the relative orientation of the sample with respect to the laser line. Moreover, this configuration allows averaging several parallel phase profiles leading to more reliable thermal diffusivity values. The experimental results are presented for a highly anisotropic material, namely, a unidirectional carbon fiber-reinforced polymer plate. [ABSTRACT FROM AUTHOR]

Within this work was explored the influence of nickel oxide decoration on the photoconductive effects exhibited by multiwall carbon nanotubes. Samples in thin film form were prepared by a chemical vapor deposition method. Experiments for evaluating the photo-response of the nanomaterials at 532 nanometers wavelength were undertaken. A contrasting behavior in the photoelectrical characteristics of the decorated nanostructures was analyzed. The decoration technique allowed us to control a decrease in photoconduction of the sample from approximately 100 μmhos/cm to -600 μmhos/cm. Two-wave mixing experiments confirmed an enhancement in nanosecond nonlinearities derived by nickel oxide contributions. It was considered that metallic nanoparticles present a strong responsibility for the evolution of the optoelectronic phenomena in metal/carbon nanohybrids. Impedance spectroscopy explorations indicated that a capacitive behavior correspond to the samples. A potential development of high-sensitive Wheatstone bridge sensors based on the optoelectrical performance of the studied samples was proposed. [ABSTRACT FROM AUTHOR]

Described herein is a spatially selective modification in the conductive effects exhibited by multi-wall carbon nanotubes decorated with platinum nanoparticles. The samples were prepared by a chemical vapor deposition processing route. The changes in the conductivity of the samples in thin film form were achieved and explored by a fringe irradiance pattern impinging on the nanohybrid materials. A vectorial two-wave mixing configuration was performed for varying the electrical behavior of the irradiated film. A noticeable reversible modification in the conductivity of the samples was induced by nanosecond pulses at a 532 nm wavelength in our experiments. The rotation of the angle between the planes of polarization of the incident waves allowed us to switch the electrical currents in a circuit with one input and two outputs. The current-conduction terminals were specifically monitored for cases where the incident beams were displaying parallel or mutually orthogonal polarizations. It was considered that functionalization and metallic decoration processes present opposite responsibilities for the evolution of the electrical phenomena in carbon nanotubes. Impedance spectroscopy measurements were undertaken and a strong dependence on electrical frequency that corresponds to an inductive action in the sample was observed. It was highlighted that the manipulation of the vectorial nature of light can be a useful tool for tuning the electrical response in nanosystems. Potential applications for developing photoconductive and filtering functions can be contemplated. [ABSTRACT FROM AUTHOR]

In this work, the photosynthetic process of maize plants ( Zea mays), which were grown using seeds inoculated with plant growth promoting bacteria Azospirillum brasilense and Burkholderia unamae, was monitored. Photothermal and photobaric signals obtained by a time-resolved photoacoustic measurement configuration were used for measuring the oxygen evolution rate in situ. A frequency-resolved configuration of the method was utilized to determine the oxygen diffusion coefficient and the thermal diffusivity of the maize leaves. The latter parameters, which can be used as indicators of the photosynthetic activity of maize, are found to vary according to the plant-microbe interaction. Treatment with plant growth promoting bacteria induced a decrease in the oxygen diffusion coefficient of about 20 %. [ABSTRACT FROM AUTHOR]

In this paper, we report about the use of an optical fiber sensor for measurements of the refractive index ( η ) of liquids as a function of wave-length ( λ ). The method uses only one optical fiber. Different laser diodes are used to carry out measurements at several wavelengths. The principle of measurement is based on the detection of the intensity of reflected light. Periodical intensity modulated light of a given λ is transmitted using an optical liquid fiber through the sample contained in a quartz glass cuvette, being reflected by a mirror located at the rear side of the cuvette back to the same fiber, through which it arrives to a photodetector after passing through a beam splitter that blocks the original beam. The signal amplitude is measured using a Lock-in amplifier synchronized at the modulation frequency as a function of the distance between the fiber tip and the cuvette for different samples of well-known η . A linear calibration curve is obtained by plotting the refractive index versus the amplitude maximum value, which can be used to measure the value of η for an unknown sample, as demonstrated by measurement of the refractive index of sodium chlorine and glucose in water solutions (in the range between 0 and 25 weight%) for different wave-lengths. Good agreement has been obtained with values reported and/or measured with an Abbe refractometer values. A dispersion relation, η ( λ ), is obtained for these samples. The described refractometer has a sensitivity of 0.56 V/RIU, its linearity is of more than 99% in the investigated range between 1 and 1.5 RIU. The limit of detection was estimated as 1.4×10 −3 RIU (RIU = Refractive Index Unit) at the used wave-lengths. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a linearly polarized 2 × 2 patch array uniformly fed by a corporate substrate integrated waveguide network for Ku band is presented. Undesired main beam steering is avoided by means of a fully corporate feeding network, although grating lobes may appear due to greater separation between radiating elements. Moreover, a reduced patch separation to avoid grating lobe appearance leads to an antenna matching coefficient degradation due to the proximity of antenna discontinuities. In consequence, a tradeoff approach has been developed, achieving a measured 4.1% matching bandwidth and a measured gain of 13.27 dBi, which corresponds to an 86% radiation efficiency. Good agreement between simulated and measured results is observed in all cases. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:587-593, 2016 [ABSTRACT FROM AUTHOR]

This work demonstrates that in photothermal experiments performed in frequency domain the heat losses due to convection and radiation should be taken into account at low frequencies for poor heat conductors. From a model-solution of the heat diffusion equation a dimensionless frequency dependent parameter M = ZH , with sample's thermal impedance Z and H the convection-radiation heat transfer coefficient, turns out to adequately quantify the importance of the effect of those heat losses. A straightforward photothermal infrared radiometry setup was designed to demonstrate the above hypothesis. Disc shaped samples of different test materials were heated by square wave modulated illumination at one of their surfaces at different frequencies using an amplitude modulated laser beam, and the temperature at the rear surfaces was monitored as a function of time using an infrared sensor. The frequency dependence of peak-to-peak values of the temperature signals was found to be consistent with the amplitude spectrum obtained by Fourier transforming the data. The frequency dependence of the peak-to-peak amplitude was compared with a theoretical model with and without taking convection and radiation induced heat losses (CRHL) into consideration. It is found that for poor heat conductors at low modulation frequencies the conventional model without CRHL does not fit well the experimental data, while the extended model leads to good agreement, resulting in reliable values for the thermal diffusivity. For the investigated samples, the contribution to the signal of thermal wave reflection at the back side of the sample turn out to have a minor effect on the signal spectrum. [ABSTRACT FROM AUTHOR]

In this paper, we resume a straightforwardly methodology that can be employed for accurate thermal diffusivity measurement by photoacoustics. The proposed methodology involves measurements in the thermally thick sample regime with normalization using a thermally thin reference sample, as well as consideration of the sample’s thermoelastic bending in both the thermally thin and thick regime. The usefulness of the method has been demonstrated with measurements in test samples of different materials. The possibilities of the method to account for linear thermal expansion coefficient have been discussed too. It has been demonstrated that for the determination of this parameter the sample must be in the ideal thermally thick regime, i.e. the range of modulation frequencies used must lie well above the cut-off frequency between the thermally thin and thick regimes. In other words, this cut-off frequency must be very small. Although this condition is very difficult to be achieved in praxis, in order to account for it, a method is proposed here that involves measurements in samples with different thicknesses and uses an extrapolation procedure. [ABSTRACT FROM AUTHOR]

A Lock-In Amplifier (LIA), or phase sensitive detector, is an instrument capable of providing high frequency selectivity allowing the user to distinguish a signal of interest from background noise, and has become an important component in the instrumentation for the study of many different physical phenomena. In this work a LIA is implemented using digital signal processing techniques on a field programmable gate array, or FPGA, and is compared against a commercial counterpart with the objective of showing that homebrewed instruments can produce reliable and trustworthy results. For this comparison experimental tests have been performed which are based on the photoacoustic effect, given that LIAs are cornerstones of many techniques based in this and other related effects. [ABSTRACT FROM AUTHOR]

We report on the use of an optical fiber sensor for the determination of concentration of contaminants in solutions below the micromolar level based on the photothermal lens effect. A pump laser beam has been added to a conventional configuration widely used as refractometer, so that the device is improved to detect tiny changes of the refractive index of a sample related to the amount of heat generated following optical absorption. In this way, concentrations as low as 0.1 μM of methylene blue in distilled water were measured. A simple experiment is also performed to demonstrate the photothermal effect. [ABSTRACT FROM AUTHOR]

Several efforts have been made to explain thermal conductivity enhancements in fluids due to the addition of nanoparticles. However, until now, there has been no general consensus on this issue. In this work a simple experiment is described that demonstrates a possible cause of misinterpretation of the experimental data of thermal conductivity obtained when using the hot-wire technique (HWT) in these systems. It has been demonstrated that the thermal conductivity of a two-layer sample of two non-miscible phase systems determined by means of the HWT must be modelled using a series thermal resistance model with consideration of the interfacial layers between different phases. This result sheds light on the thermal conductivity enhancement in nanofluids with respect to the values corresponding to the base fluid, suggesting that this increase can be explained using the above-mentioned model and not by application of empirical formulae for effective media, as done before. [ABSTRACT FROM AUTHOR]

A technique is proposed for thermal diffusivity measurement in fluids. It is based on the Angstrom method, but with excitation of thermal waves by electromagnetic energy absorption and pyroelectric detection. The good agreement between measured thermal diffusivity of air and some test liquids with literature values shows the validity of the method. It is free of some limitations of conventional photopyroelectric technique with length scanning because it is free of moving parts inside the sample and because it avoids problems associated with the non-parallelism between thermal wave generator surface and sensor. It does not require any data normalization procedure or special sample preparation. [ABSTRACT FROM AUTHOR]

The effect of titanium dioxide photocatalysis against bacteria that are dangerous for human health has been investigated in the past, suggesting the possibility of using a specific behavior for each microorganism during this process for its discrimination. In this study, the behavior of some plants' growth promoting bacteria ( Burkholderia unamae (Strain MTI 641), Acetobacter diazotrophicus (Strain PAl 5), A. diazotrophicus (Strain CFN-Cf 52), and B. unamae (Strain TATl-371)) interacting with light and bactericidal titanium dioxide films have been analyzed using the photoacoustic technique. The monitoring of these interactions shows particular characteristics that could serve for identifying these species. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a photoacoustic method is proposed for specific heat capacity measurements in solids using a heat transmission configuration, where illumination takes place at the reference–sample interface. The method involves the use of a liquid reference sample so that it becomes free of instrumental function influence due to effects dependent on the detection cell, the frequency dependence of the microphone response and of the involved electronics. The method is validated with measurements performed in test samples of different materials. [Copyright &y& Elsevier]

A simple method for thermal-diffusivity measurement in low thermal-conductivity solids is proposed on a basis of the analytical solution of the heat diffusion equation for a solid plate with uniform continuous heating at one of its surfaces. The method involves combined measurements of the temperature evolution at both the front (illuminated) and rear surfaces of the sample in both the thermally thin and thick regimes. The principal advantage of the method is its independence on a knowledge of the convection and radiation heat loss coefficient, and hence, the non-necessity of performing measurements in blackbody similar samples under vacuum conditions. If these conditions are achieved, the thermal conductivity and specific (volume) heat capacity could also be achieved. [ABSTRACT FROM AUTHOR]

Abstract: A pyroelectric sensor can be seen as a layered system consisted on a pyroelectric material sandwiched between two thin metal layers acting as electrical contacts for measurements of the voltage drop that can be induced by heating. This kind of sensor can be used as a detector of electromagnetic radiation but also for thermal characterization of materials using the photopyroelectric technique. In this work we perform a theoretical analysis based in the so-called thermal wave approach to show that, when this sensor is heated periodically by the absorption of intensity modulated light by one of the metalized surfaces, while the other metal surface is in contact with a liquid sample, the resulting pyroelectric voltage signal amplitude enhances respecting the one resulting from the bare sensor, for certain values of the modulation frequency. This contradicts the intuitively expectation based in the assumption that the sample provides a new channel for heat conduction, thereby decreasing the pyroelectric temperature. We will show that the back and forth propagation and the superposition of thermal waves through the metal coatings must be taken into account in order to explain the observed behavior. The proposed model was experimentally tested for water and glycerin samples, and using a polyvinylidene difluoride (PVDF) polymer film, with Ni–Cu metal electrodes, as a pyroelectric sensor. [Copyright &y& Elsevier]

American trypanosomiasis is an important zoonotic disease which affects more than 15 million persons in America. In Mexico, Chagas’ disease is widely distributed in the country mostly in states with tropical weather conditions, including Yucatan. A cross-sectional study was performed on serum samples from 35 dogs and their owners ( n = 75) from the south area of Merida city. Specific IgG antibodies against Trypanosoma cruzi ( T. cruzi) using enzyme-linked immunosorbent assay, Immunofluorescence antibody test (IFI) and Western blot (WB) were detected. The overall percentage of seropositivity was 34% in dogs and 8% for sampled owners. Some owners brought samples of insect vectors found in their households, which were kept with BALB/c mice as a source of food and which were evaluated by polymerase chain reaction. All tested insects were positive to T. cruzi, and BALB/C mice were IFI and WB positive after 45 days in contact with these vectors. Further investigations showed that there is a high risk of infection with Chagas disease in dogs which spend the night outdoors ( P < 0.05), with low body conditions score and older dogs. Risk factors identified to be associated to the infection in owners were gender and occupation (bricklayers, P < 0.05). The presence of seropositive dogs in houses where vectors are well-adapted represents a high risk for humans to become infected when bitten by a vector infected by a positive dog. [ABSTRACT FROM AUTHOR]

Abstract: The photo-induced charge transfer in four series of Prussian blue (PB) analogues was studied from photoacoustic spectra. In cobalticyanides the observed signals were assigned to a metal-to-ligand charge transfer, which appears as a shoulder below 450nm, and to d–d transitions for Co(II), Ni(II) and Cu(II) complex salts. No evidence of metal-to-metal charge transfer was observed for this series, which is probably due to the high stability of low spin cobalt(III) in the hexacyanide complex. Photoacoustic spectra for ferricyanides are broad bands, which result particularly intense up to 750nm. Such features were attributed to the overlapping of contributions from metal-to-ligand (<600nm) and metal-to-metal charge transfer transitions, with probably also a minor contribution from d–d transitions in the outer metal. The spectra for the ferrocyanides series are dominated by the metal-to-ligand charge transfer band below 550nm, approximately 100nm above this transition in cobalticyanides. Within the studied solids, the most intense and broad metal-to-metal charge transfer bands were found for a series of low spin Co(III) high spin Co(II) hexacyanoferrates(II,III) and with similar features also for ferric ferrocyanide (Prussian blue), assigned to Fe(II)→Co(III) and Fe(II)→Fe(III) photo-induced transition, respectively. The first of these transitions requires of more energetic photons to be observed, its maximum falls at 580nm while for Prussian blue it is found at 670nm. Prussian blue analogues are usually obtained as nanometric size particles and many of them have a microporous structure. The role of surface atoms on the observed charge transfer bands in the studied series of compounds is also discussed. [Copyright &y& Elsevier]

We show that the Photo-Acoustic Spectroscopy (PAS) is an useful alternative method for the determination of the optical-absorption coefficient of CdTe thin films, in the spectral region near to the fundamental absorption edge, ranging from 1.0 eV to 2.4 eV, using an open cell in the transmission configuration. We applied this method to the optical characterization of CdTe layers for several values of their thickness. These CdTe samples were deposited by closed-space vapor transport (CSVT) technique under different growth conditions. [ABSTRACT FROM AUTHOR]

Age and growth of Sardinella aurita larvae were analyzed based on daily growth increments in sagitta otoliths. Larvae were obtained from ichthyoplankton samples collected from the outer shelf off Margarita Island and from Mochima Bay (northeastern Venezuela), between March 1999 and January 2001. Total length, standard length (SL) and height of larvae were measured and the otoliths were examined under a light microscope. Larval size ranged from 1.35 to 15.90 mm SL, the Margarita Island larvae being signicantly larger than those from Mochima (t = 18.69; P < 0.001). The three morphological parameters were significantly and positively correlated among themselves and with otolith diameter and age, and fitted to a linear regression model; hence, size growth as a function of age was not different between the localities studied (SL = 2.65 + 1.10 × age; r² = 0.78, P < 0.001). Growth rates per locality were also determined by backcalculating sizes, with no significant differences (F = 2.60, P > 0.05) between them. The mean backcalculated growth rate was 0.99 mm day-1 and it was not significantly different from the mean growth rate obtained from fitted length-age data (F = 3.32, P > 0.05). Morphological changes in otoliths were evident from the mean daily increment widths, with wider increments in larval otoliths from Margarita Island (H = 42.54, P < 0.001). [ABSTRACT FROM AUTHOR]

A letter to the editor on "Specific heat of the Ba0.7Sr0.3Ti1−yZryO (y = 0, 0.03, 0.05, 0.1) ferroelectric ceramics obtained by the temperature relaxation method," by S. García, E. Marín, O. Delgado-Vasallo, J. Portelles, J. M. Siqueiros, E. Martínez, & J. Heiras in August 2006 issue is presented.

Age and growth of Sardinella aurita larvae were analyzed based on daily growth increments in sagitta otoliths. Larvae were obtained from ichthyoplankton samples collected from the outer shelf off Margarita Island and from Mochima Bay (northeastern Venezuela), between March 1999 and January 2001. Total length, standard length (SL) and height of larvae were measured and the otoliths were examined under a light microscope. Larval size ranged from 1.35 to 15.90 mm SL, the Margarita Island larvae being signicantly larger than those from Mochima (t = 18.69; P < 0.001). The three morphological parameters were significantly and positively correlated among themselves and with otolith diameter and age, and fitted to a linear regression model; hence, size growth as a function of age was not different between the localities studied (SL = 2.65 + 1.10 × age; r² = 0.78, P < 0.001). Growth rates per locality were also determined by backcalculating sizes, with no significant differences (F = 2.60, P > 0.05) between them. The mean backcalculated growth rate was 0.99 mm day-1 and it was not significantly different from the mean growth rate obtained from fitted length-age data (F = 3.32, P > 0.05). Morphological changes in otoliths were evident from the mean daily increment widths, with wider increments in larval otoliths from Margarita Island (H = 42.54, P < 0.001). [ABSTRACT FROM AUTHOR]

In this paper we present an alternative approach for obtaining the mean results of the Bohr's model of the atom. The starting point in our analysis will be the Bohr's correspondence principle, and we will discuss how it predicts the angular momentum quantization rule. It is also our purpose here to show how relativistic corrections to the Bohr model of the atom can be easy obtained from our approach as well as the concept of fine structure. We will also provide and discuss at elementary level some examples of phenomena which can be used to illustrate that the old Bohr's theory can still make an important contribution to their understanding. [ABSTRACT FROM AUTHOR]

Relative indices of abundance by age class for bluefin tuna from 1975 to 2000 were estimated using generalized linear mixed models. Age class was included as a fixed factor within the model specifications, with the Year×Age interaction as a fixed factor component in order to obtain annual indices by age. Catch and effort data on bluefin tuna were available from two sources, catches by trip, and daily catches from logbooks. Catches were modelled using the delta-lognormal model. The model finally selected included the following explanatory factors: Year, Age, Year×Age, Month, number of Crew, number of Bait Tanks, and with the Year×Month interaction as a random component. Overall, year trends and coefficients of variation were similar from both datasets by age class. In general, the standardization procedure showed that vessel characteristics and technological advances related to fishing have a relatively minor explanatory effect on the observed catch rates of bluefin tuna in the fishery. Neither geographical distribution nor type of bait had an explanatory effect on the observed catch rates. The 1994 cohort stands out as an exceptionally large year class; it can be followed through the standardized series. This standardized catch rate index at age of bluefin tuna is the most complete yet available and is the only one currently used for juvenile fish in calibrating population models to evaluate the Eastern Atlantic and Mediterranean stock. It is particularly valuable because, apart from improvements in electronic technology, there are no changes in the method of exploitation during the entire series. [Copyright &y& Elsevier]

A laboratory experiment is described which employs a relaxation method for the measurement of the specific heat at constant pressure of solids at room temperature. The experiment employs measurements of the cooling (or heating, rate of a sample whose temperature differs from that of the surroundings due to light heating. This rate depends on the temperature difference, the specific heat of the sample and the heat transfer coefficient. The sample is suspended adiabatically in a reservoir in which a vacuum can be made. The influence of heat dissipation by convection on the results is discussed for the first time for this kind of experiment. The theoretical aspects related m the described technique involve concepts from several branches of physics that makes the experiment of interest and suitable for students at undergraduate and graduate levels of physics, material sciences and engineering. [ABSTRACT FROM AUTHOR]

The temporal evolution of calcium concentrations in precipitation over Europe during the period 1986-1997 is examined using panel data. The use of panel data techniques allows us to determine the temporal evolution of groups of stations rather than analysing the temporal behavior of each of them. The analysis reveals two different temporal patterns: Peripheral, and Central. We find a significant increasing trend ( p < 0.01) in Peripheral Pattern. The annual increase is +0.047 mgL -1 yr -1 . However the Central Pattern is characterized by a significant decreasing trend ( p < 0.00001) and the annual decrease is -0.024 mgL -1 yr -1 . The standard errors of panel data estimates are around 25% smaller than those of aggregate time series regression. The use of panel data produces higher R 2 values than aggregate data. This technique takes into account the individual heterogeneity, allows a larger number of data points and improves the efficiency of the estimates. [ABSTRACT FROM AUTHOR]

BSTRACT: The effect of heat on lactoperoxidase activity in bovine milk was studied over a range of 68 to 76 °C. Values of residual enzymatic activity after different treatments were studied by kinetic analysis, obtaining D-values and the Z-value (3.1 °C). Denaturation of lactoperoxidase, measured by loss in activity, can be described as a 1st-order reaction. Rate constants were calculated, as was the energy of activation, which was 737.69 kJ/mol. Thermodynamic parameters were also calculated. The high value obtained for the variation in enthalpy of activation indicates that a high amount of energy is required to initiate denaturation, probably due to the molecular conformation of lactoperoxidase. [ABSTRACT FROM AUTHOR]

Roughhead grenadier Macrourus berglax Lacépède 1802, is becoming an important commercial fish in the north-west Atlantic fisheries and reliable age information is needed for its assessment. Macrourus berglax has been aged by counting otolith growth zones assumed to represent anulli. Three validation methods were applied: back-calculation of length-at-age, length–frequency analysis, and analyses of the progression of the length mode of an exceptionally large year class. Results on size-at-age estimated by otolith growth zone counts, length–frequency analysis of pre-anal fin length and modal progression were internally consistent, but estimates by back-calculation were different. This latter method produces unrealistic growth curves for each sex due to the weak relationship between otolith size as measured and pre-anal fin length. Up to age 8–9 the size-at-age were the same for males and females; thereafter males were smaller than females. Male growth rate declined when pre-anal fin length reached 18 cm at around age 9, whereas the growth of females started to decline at about 30 cm at around age 16. The Von Bertalanffy growth model derived from otolith analysis was similar to that obtained by the Multifan length frequency analysis model, and gave realistic values of L inf , close to the maximum anal fin lengths found in catches. The results showed that Macrourus berglax has a prolonged life cycle and differences in growth between males and females. [ABSTRACT FROM AUTHOR]

In this paper we discuss the use of an alternative photothermal technique for measurements of thermal properties of liquid mixtures. The proposed technique is based upon the concept of a thermal wave interferometer. The liquid sample is confined between two thin pyroelectric detectors. One of these detectors acts as a modulated light absorber while the other is used for sensing the temperature fluctuations transmitted through the liquid layer. It is demonstrated that the proposed experimental configuration allows us to fully characterize the thermal properties of the constituent liquids. [ABSTRACT FROM AUTHOR]

SummaryListeria monocytogenes is a facultative intracellular pathogen which is internalized by host mammalian cells upon binding to their surface. Further listerial growth occurs in the cytosol after escape from the phagosomal–endosomal compartment. We have previously reported that C1q is able to potentiate L. monocytogenes phagocytosis upon bacterial opsonization by ingestion through C1q-binding structures. In this report, we analysed the post-phagocytic events upon internalization of C1q-opsonized L. monocytogenes and found an induction of macrophage (Mφ)-like IC-21 cell bactericidal mechanisms displayed by the production of oxygen and nitrogen metabolites. Both types of molecules are effective in L. monocytogenes killing. Further analysis of the cellular responses promoted by interaction of C1q with its surface binding structures, leads us to consider C1q as a collaborative molecule involved in Mφ activation. Upon interaction with surface binding structures, C1q was able to trigger and/or amplify the production of reactive oxygen and nitrogen intermediates induced by stimuli such as interferon-γ and L. monocytogenes phagocytosis. [ABSTRACT FROM AUTHOR]

In this paper we present a thermal characterization of Al[sub y]Ga[sub 1-y] As alloys grown by liquid phase epitaxy on GaAssubstrates, by means of the open photoacoustic cell detectiontechnique and the temperature-rise method under continuous lightillumination. The values of the thermal conductivity, diffusivity andspecific heat were obtained in the 0≤y≤0.5 region, where the Al[sub y] Ga[sub 1-y] As band gap is mainly direct. The technique presented here is based upon an effective sample model which is shown to be suitable for the determination of the thermal properties of two layer semiconductor specimens. [ABSTRACT FROM AUTHOR]

This letter explains briefly why so-called thermal waves are not truly waves- despite being described mathematically as such-because of their intrinsic diffusive character. This topic should be of interest to those students and teachers dealing with heat transport in the presence of non-stationary harmonic heat sources, photothermal phenomena and techniques, and other related subjects. [ABSTRACT FROM AUTHOR]

In this work, it intends to establish a possible spectral correlation between both techniques, Natural Gamma and Mössbauer Spectrometry, when they are applied to the study of the mineral matter of the coal (ash); in order to have an available method more reliable in the determination of the content of ash in the coal. We can reach this, in the technical natural gamma, by associating proportionally the spectral areas of soils and coals, with the quantity of matter mineral present in a given sample; and in the Mössbauer spectrometry, we do it, identifying the different iron species that are present in the coal, some of them, are composed of diverse chemical elements as S, Al, Si, K, etc. and potentially they can give outstanding information about the quantity of ash in the sample (in accordance with its corresponding spectral area). After obtaining the respective gamma natural and Mössbauer spectra of 10 different coal samples, to analyze them and to compare their areas with the percentage of ash of each sample (previously well-known for analysis thermo-gravimetric), and also, after to compare them, the best natural gamma-Mössbauer correlation, is observed in the jarosite case, according to the hypothesis for this work; in general the obtained lineal correlation coefficients are in the range since 0.70, until a little more of 0.90. [ABSTRACT FROM AUTHOR]

The article discusses the concept of thermal effusivity and the role of this parameter in understanding thermal physics concepts. The use of thermal effusivity instead of thermal conductivity is emphasized in explaining why we feel that one body is hotter or colder when we touch objects of equal temperature but of different materials.

A gas analyzer device based on thermal wave interference in a cavity is presented. The thermal diffusivity of CO[sub 2]:air mixtures as a function of the relative concentration is measured. It is demonstrated that different concentrations of CO[sub 2] in air can be detected with accuracy using the described experimental device. The results presented here open the possibility to perform routine measurements of thermal diffusivity of binary gas mixtures and using this parameter to monitor the relative gas concentration. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lock-in thermography (LIT) is implemented using a non-research grade camera and dedicated software. • Laser-spot-LIT applications are demonstrated. • Thermal diffusivity of solids was measured. • Cracks between solid sheets in contact were visualized. • Convective effects in low-viscosity liquids were visualized. • Advanced non-destructive testing with low-cost LIT thermography systems is possible. The widespread use of Lock-in Thermography (LIT) has been hindered by the high cost of the thermographic cameras available for such applications. We show that a low-cost thermographic camera (we used the QIANLI MEGA-IDEA Super iR Cam 2S) can be straightforwardly used in advanced applications, particularly for measuring the thermal diffusivity of solids using the Laser Spot LIT Technique and the Slope Method. The results of measurements performed in test samples were compared with those obtained using the FLIR SC5000 research-grade camera, whose usefulness for this kind of application has been demonstrated before. The Super iR Cam 2S is almost two orders of magnitude cheaper than the FLIR SC5000 but has an inferior performance. However, a good agreement between the thermal diffusivities of materials, with values between 10 and 100 mm2/s, obtained using both cameras and those reported in the literature demonstrates inexpensive instrumentation usefulness for conducting high-quality research work. The visualization of cracks between samples with different diffusivities was demonstrated too. For the first time, we also show the possibility of using Laser Spot LIT to directly observe a convective effect in a fluid layer closest to the sample's surface. [ABSTRACT FROM AUTHOR]

Abstract Emulsions are crucial in the treatment of snake bites to bust the antibody response of the inmunogen. The widely used Freund's emulsion typically combines 50/50 water-oil (W/O) phase. However, its use is limited because it is associated with tissue damage. We formulated and characterized a Pickering Emulsion 70/30 (W/O) that uses a chemically modified hydrophobic hydroxyapatite as surfactant. This Pickering emulsion has similar rheologic behavior to Freund's emulsion 50/50, but with lower oil and surfactant concentration. Evaluation of cell recruitment, antibody response and adhering tissue in mice immunized with B. asper of Pacific venom and treated with Freund's and Pickering 70/30 emulsions resulted in similar adjuvant activity (only 18% lower in Pickering 70/30 emulsion). However, Pickering 70/30 emulsions minimized negative side effects in the host animals and showed better ease of flow that favors injection of the host. Our results open up room for optimization and improvement of Pickering emulsion based on modified nanoparticles for medical applications. Highlights • A new Pickering Emulsion 70/30 (W/O) using hydrophobic hydroxyapatite as solid material was formulated and characterized. • It has much lesser oil and surfactant that Freund´s emulsion, but similar reological behavior. • It has only 18 % lower adjuvant activity than Freund's emulsion with a minimized negative side effects in the host animals. [ABSTRACT FROM AUTHOR]

The populations of three members of the Neotropical silverside fish from the Poblana genus of the Atherinopsidae family (Poblana alchichica, P. letholepis, and P. squamata) are microendemic species restricted to the eastern basin of central Mexico, where each Poblana species is limited to each crater lake. The aim of this study was to characterize the potential differences in functionality and diversity of digestive proteases between three Poblana species as a likely result of physiological digestive adaptations over the speciation process. Adults of the three Poblana species were collected from three different crater lakes and the activity of digestive proteases and their functional characteristics under different pH and temperature conditions and the number and size of alkaline proteases were determined using biochemical and electrophoretic techniques. The three Poblana species showed acid protease activity and high chymotrypsin activity; likewise, the optimum pH was 8 for alkaline proteases and ranged between 2 and 3 for acid proteases. Alkaline proteases showed an optimum temperature peak at 60°C, while acid proteases showed two peaks (at 30°C and 60°C). The presence of aspartyl peptidases in all three species was confirmed using an inhibitor pepstatin A. The SDS-PAGE zymogram showed four activity bands with alkaline proteolytic activity (45.4, 39.0, 27.9, and 17.4 kDa) in P. alchichica, five bands (58.0, 45.4, 39.0, 27.9, and 17.4 kDa) in P. letholepis, and five bands (126.9, 69.7, 39.0, 27.9, and 17.4 kDa) in P. squamata. Therefore, the studied Poblana display slight differences in protease function and in the number of protease isoforms as a result of allopatric speciation processes and probably of diet selectivity. [ABSTRACT FROM AUTHOR]

Biological pigments are chemical compounds that absorb light in the wavelength range of the visible region. They are present in all living organisms, vegetables being among their main producers. In this work, the photoacoustic spectroscopy technique was used to investigate some qualitative features related to pigments of ground and roasted coffee. The samples were collected at several Colombian commercial markets from different regions. Colombian coffee is known worldwide for its quality and flavor, being the main agricultural export product of the country. Therefore, it is important to study the composition and color of ground and roasted coffee in order to show quality and special characteristics of local varieties. Studying the content of pigments after roasting and grinding the coffee can allow a better understanding of the coloring process, which can lead to the definition of new criteria for evaluating the quality and other characteristics of the final product by comparing the optical spectra. In this work, the optical absorption spectra obtained by photoacoustic spectroscopy show absorption bands that match those of the pigments capsanthin, lutein and chlorophyll. In addition, an absorption peak in the near-infrared region was revealed, which also provides information regarding the composition of roasted and ground coffee. [ABSTRACT FROM AUTHOR]

A gas sensing device based on a thermal wave resonator cavity is outlined. It is experimentally tested by monitoring the presence of several hydrocarbon vapors in air via the measurement of the thermal diffusivity. It is also shown that its time-dependent response may be used to follow the vapor diffusion. It is shown that its characteristic response time is linearly correlated to the thermal diffusivity value of the mixture. The steps toward the development of a practical sensing device are further discussed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This paper introduces a novel application of laser spot step heating thermography, namely the visualization of a convective phenomenon. A fluid confined in a measurement cell is in intimate contact with the inner face of a thin vertical metallic sheet, on whose external surface a laser beam is tightly focused generating heat that diffuses to the closest part of the fluid layer adjacent to the sample decreasing its density locally. This induces a density gradient that generates internal motion of the fluid affecting thermograms recorded on the external side of the sheet, which are visualized after a given time has elapsed since the laser is switched on. The results of these measurements agree with those obtained using the finite-element analysis simulation software COMSOL Multiphysics®. A simple model for free convection explains why the effect is only observed for some fluids. [Display omitted] • Laser spot step heating thermography is used to visualize convective flow. • Fluid is in contact with a metallic sheet with a superficial punctual heat source. • The induced motion of the fluid affects thermograms recorded on the sheet's surface. • Thermograms are recorded after a time has elapsed since the laser is switched on. • Asymmetries in vertical temperature profiles show the effects of convection. [ABSTRACT FROM AUTHOR]

In developing countries, residual biomass usage by means of anaerobic digestion offers several benefits and opportunities, such as a sustainable energy source, production of organic fertilizers and new agrobusiness models. In Latin America, Colombia is one of the most promising markets for the implementation of this technology in terms of availability of biomass and economic growth, as recently reported by local government organizations. In this paper, special attention is given to Antioquia, a department of Colombia with the largest farms of cattle and pigs, according to information reported in 2018 by the Ministry of Agriculture and Rural Development. It is estimated that manure from the porcine subsector in Antioquia has an approximate technical-energy potential of 1,896 TJ year-1, varying from 1,611 to 2,186 TJ year-1, corresponding to the 95% confidence interval. In the case of manure generated by the livestock subsector in Antioquia, it is estimated a theoretical energy potential of 8,566 TJ year-1. However, traditional extensive production systems disseminate manure through the pastures turning centralization of the available residual biomass a difficult task and not senseful. Based on the local practices of the specialized dairy subsector, it is estimated that manure collected during the milking process could reached up to 25% of the total available. Biochemical conversion of this amount of biomass has an estimated technical-energy potential of 187 TJ year-1, varying from 156 and 236 TJ year-1, corresponding to the 95% confidence. The aim of this article is to estimate the technical-energy potential for the livestock and porcine subsectors in the Department of Antioquia, based on the available residual biomass according to local farming practices. [ABSTRACT FROM AUTHOR]

This article discusses the use of the functional endoscopic luminal imaging probe (endoFLIP) in the treatment of achalasia, a condition that affects the proper functioning of the lower esophageal sphincter. The preferred treatment for achalasia is the peroral endoscopic myotomy (POEM) technique, and the endoFLIP is a valuable tool used during this procedure. The article presents a case study of a 72-year-old man with achalasia who underwent the POEM procedure with endoFLIP measurements before and after the surgery. The results of the procedure were positive, as indicated by improvements in the patient's symptoms and scores on questionnaires assessing the severity of achalasia and malnutrition. The article concludes that the use of endoFLIP during POEM can help minimize the risk of postoperative reflux and reduce the likelihood of symptom recurrence. [Extracted from the article]

We report on characterization of bio-additive from Jatropha curcas L. oil (JBA) in mineral-based oil (MBO) at different viscosities with 10 % and 20 % ratios blends of JBA. Measurements of kinematic viscosity and mass density were carried out to know the physical changes of MBOs when JBA is added. Also, a thermal characterization of the samples was performed. The thermal conductivity, k, and specific heat, c, were obtained using their relationship with thermal effusivity, e, and thermal diffusivity, α, which were determined by the front and back photopyroelectric techniques, respectively. We show that a correlation between kinematic viscosity and thermal conductivity exists with the percentage of JBA in the blend. The obtained thermal conductivities values were compared with those retrieved using the hot-wire technique showing a good agreement. JBA demonstrated special features to improve the thermal properties and to be able to be used as a viscosity modifier of the MBOs, which could be reflected in a better performance in machinery that uses engine oil. [ABSTRACT FROM AUTHOR]