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Pleurodema guayapae is a species that inhabits saline environments and semidesert zones from cen- tral Argentina. To date, the knowledge about the reproductive biology of this species is very poor, and our aim is to contribute to its knowledge with the description of some important reproductive aspects. For this, field work was undertaken in an area near to Patquía, La Rioja province. Sampling was undertaken during three summer periods (2006-2007; 2007-2008; 2008-2009) in Chamical-Patquía area, where we could find reproductively active populations. We observed and described breeding sites, type of clutch, process of foam nest construction, clutch and egg number and sizes, and hatching time and stage. Behaviour observations were performed from the time that males began to call until the pairs ended up the foam nests building, and layed the eggs. Additionally, one amplected pair was observed and filmed in the process of foam nest construction, and four amplectant pairs were collected and separatelly placed in plastic containers, for nests observations in the laboratory. Hatching time was based on three different foam nests of known age. We found that P. guayapae populations were acoustically active only after a rainfall. Its breeding sites were represented by ephemeral ponds of fresh water, product of rains. The males emitted their calls inside or outside these ponds. A detailed description of the foam nest construction process by both females and males was made. The clutches were in dome-shaped foam nest type of 6-9cm in diameter and 1-3cm in height, some of which were in communal nests. The nests had an average of 1 137 pigmented eggs. This species showed a short hatching time. Our results allow us to conclude that this species should be considered an extreme explosive breeder. Our results are discussed with others obtained for related species. [ABSTRACT FROM AUTHOR]

The progress made in recent years in the area of micro total analysis system (μ-TAS) has allowed the development of analytical tools for determination and measurement of elements and compounds that previously required bench laboratory equipment for such purposes. μ-TAS provides a high degree of sensitivity and they are simple and affordable. This work details a process by which classical colorimetric methodologies used in analysis have been adapted from discontinuous to continuous flow systems, for determination of cobalt in aqueous solutions in real time. The purpose of this adaptation is the subsequent system miniaturization using low temperature co-fired ceramics (LTCC). The adapted methodology for the colorimetric determination of cobalt uses 3-Hydroxy-4-nitroso-2,7-naphtalene disulfonic acid disodium salt or nitroso-R salt (NRS) as the main reagent, in an environment of acetate and sodium citrate which favors the reaction. The carrier solution is prepared with sulfuric acid. The system encompasses a microfluidic structure in LTCC, a peristaltic pump to maintain the continuous flow, a six-way valve for sample injection, and an issuer of light of 540 nm based on a multiled. Using the integrated circuit TCS3414, the signal is sent to the computer wirelessly through zigbee protocol, and at the end a LabVIEW-based application shows the absorbance for a range of concentrations between 0.5 and 10 mg/L. [ABSTRACT FROM AUTHOR]

The design and construction of a colorimetric microsystem in continuous flow for the automated, real-time measurement of cobalt in acqueous solutions is presented. Low temperature cofired ceramics (LTCC) technology is used to build the fluidic platformaiming at the miniaturization of the device. Absorbance measurements are done through the clear windows of a flow cell integrated monolithically in the platform. The detection system is a green LED, emitting light at a wavelength of 540 nm, a photodetector and a data acquisition card. Virtual instrumentation is used to process, store and display the acquired signals. The results are compared to those produced with a benchtop spectrophotometer. [ABSTRACT FROM AUTHOR]

Several methods to enhance the efficiency of paper electroperforation processes are presented in this work. In all the cases, the discharge confinement effect is used for obtaining higher perforation densities than those found in the standard industrial processes. To quantify the efficiency of the proposed methods, statistical tools are used to characterize the 2-D perforation pattern. [ABSTRACT FROM AUTHOR]

In this paper, the low-temperature co-fired ceramics (LTCC) technology, which has been commonly used for electronic applications, is presented as a useful alternative to construct continuous flow analytical microsystems. This technology enables not only the fabrication of complex three-dimensional structures rapidly and at a realistic cost but also the integration of the elements needed to carry out a whole analytical process, such as pretreatment steps, mixers, and detection systems. In this work, a simple and general procedure for the integration of ion- selective electrodes based on liquid ion exchanger is proposed and illustrated by using ammonium- and nitrate- selective membranes. Additionally, a screen-printed reference electrode was easily incorporated into the microfluidic LTCC structure allowing a complete on-chip integration of the potentiometric detection. Analytical features of the proposed systems are presented. [ABSTRACT FROM AUTHOR]