La participación de los actores en la investigación en Trabajo Social: una dimensión ética necesaria

En esta ponencia se pretende hacer hincapié en la participación de los actores y las diversas implicaciones éticas que se dan en una investigación, partiendo de las reflexiones críticas, que se han realizado al entorno de este tema en la investigación sobre trabajo social con las familias que está llevando a cabo el Grupo de Investigación e Innovación en Trabajo Social (GRITS), al que pertenecen sus autoras. Se centra en los aspectos éticos a tener en cuenta en la investigación en general y especialmente en la investigación cualitativa, que siguiendo a Peled y Leichtentritt (2002) 1 son: a) La ética en la investigación es un aspecto integral de ésta en cada una de sus fases; b) La investigación ética da poder a los participantes especialmente a aquellos más vulnerables; c) La investigación ética beneficia a los participantes; d) La investigación ética prevé que no se pueda causar ningún mal a los participantes ni a aquellos con quienes tengan relación; e) Requiere que los investigadores sean competentes (p. 148). This presentation is about the ethical dimension in social work research focused mainly about the degree of participation of the different actors in the research. It comes from the critical reflections that the authors have been analysing in the research about social work with families which is being performed in the framework of GRITS (Group for Research and Innovation in Social Work). It deals with the ethical aspects to be considered in research in general and specially in qualitative research which following Peled and Leichtentritt (2002) are: (a) research ethics are an integral aspect of the research act and of each of the phases of the research process; (b) ethical research empowers participants, particularly those of vulnerable and disenfranchised groups; (c) ethical research benefits participants; (d) ethical research prevents harm for participants and involved others; and (e) ethical research requires researchers' technical competence. (p.148

Double aluminum recovery and its reuse in wastewater treatment

This work evaluates the use of aluminum contained in the aluminum–polyethylene films as anodic electrodes using the electrocoagulation technique to reduce the pollutant contents of industrial wastewater quickly and effectively. Thermal treatment at 500 °C produces pure aluminum (according to TGA and SEM/EDS analysis) which is used to construct aluminum disks (applying 6 tons/cm2 of pressure). Aluminum disks are used as cathodes and anodes in an electrochemical cell. The current density applied in the recovered Al electrodes was 12 mA cm−2, and the maximum COD reduction of wastewater was 77 % at 25 min of treatment. The color and turbidity reductions are 87 and 90 %, respectively. The resulting sludge of wastewater treatment was thermally treated and a second aluminum recovery was reached; since the organic material present in the sludge was removed by the high temperature, the obtained aluminum was pure enough for its reuse. The use of aluminum–polyethylene films as electrodes in the electrocoagulation process contributes to the pollutant removal without the addition of chemical reagents or changing the pH, so it is both effective and environmentally friendly.UAEM-UNAM CONACY

Gamma radiation as a recycling tool for waste materials used in concrete

Over the course of the last 50 years, a large number of major technological advances have contributed to the development of higher-strength, high-performance materials that provide excellent benefits. Nevertheless, in most cases, after a very short useful life, these products become waste material and contribute to environmental degra‐ dation. This situation has created an environmental crisis that has reached global proportions. In efforts to combat this issue and to promote sustainable development and reduce environmental pollution, some investigations have focused on recycling using innovative and clean technologies, such as gamma radiation, as an alternative to conventional mechanical and chemical recycling procedures. In this context, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete; for example, the compressive strength and modulus of elasticity are improved by the addition of waste particles and application of gamma radiation. In this chapter, we propose the use of gamma radiation as a method for modifying waste materials; for instance, polyethylene terephthalate plastic bottles, automotive tire rubber, and the cellulose in Tetra Pak containers, and their reuse to enhance the properties of concrete

Acumulación simultánea de múltiples metales pesados por cultivos in vitro de plántulas de Prosopis laevigata

Se investigó la capacidad de plántulas de Prosopis laevigata para tolerar y acumular de forma simultánea hasta 4 metales pesados (cromo, níquel, cadmio y plomo), bajo condiciones de cultivo in vitro.Experiments were conducted to investigate the capability of Prosopis laevigata to individually or simultaneously uptake four heavy metals (HM; Cr, Ni, Cd, and Pb). To this end, P. laevigata seedlings were cultured during 50 days on modified MS medium supplemented with 30 g L−1 of sucrose and added with 1, 2, 3 or 4 HM (50 mg L−1 of each HM). When the four HM were added simultaneously, the medium was supplemented with or without ethylenediaminetetracetic acid (EDTA). In the MS media contained only one HM, the seedlings tolerance to HM was as follows: Pb≥Cr>Ni≥Cd. The accumulation of HM from higher to lower concentration in shoots was Pb≥Ni>Cd>>Cr and in roots Cr>>Pb>>Ni>Cd. When the media contained more than one HM, the accumulation in shoots was the highest for Ni and the lowest for Pb, whether EDTA was added or not. EDTA supplementation increased 61, 39, 22, and 3 fold uptake of Cr, Ni, Pb, and Cd in roots, respectively

Effect of ionic liquids on the structural, thermal and in vitro degradation properties of poly(ε-caprolactone) synthesized in the presence of Candida antarctica lipase B

The study provides detailed information on the differences in the structural, thermal and degradation properties of poly(e-caprolactone) synthesized in two different ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [bmim][NTf2], regarding its further usage in the pharmaceutical field. The polymer structure confirms the presence of both linear polymer chains with end-functional hydroxyl groups allowing covalent coupling of the therapeutic agents, and cyclic macromolecules, both affecting the degree of crystallinity of polymer. The highest macrocyclic content (64%) after 7 days of polymerization at 80 8C was observed for [bmim][NTf2]. For [bmim][PF6], the macrocyclic content value was not dependent on the reaction time and remained at a similar level (10–14% at 80 8C). The results of degradation test revealed that hydrolytic degradation of ester bonds is more pronounced for PCLs synthesized in [bmim][NTf2], due to their lower degree of crystallinity compared with PCLs obtained in [bmim][PF6]. A high purity, low polydispersity index of the obtained polymers and high yield of the process (ca., 90%) indicate that ionic liquids seem to be promising solvents for the synthesis of biomedical polymers

Recycled cellulose from Tetra Pak packaging as reinforcement of polyester based composites

Addressing the environmental problems caused by waste generated by Tetra Pak packaging, in this work, polyester based composites with 80% of polyester resin and 20% of silica sand were elaborated; where the silica sand was partially replaced by recycled cellulose from waste Tetra Pak containers at concentrations of 1, 2, 4 and 6% by weight. Both recycled cellulose and composite specimens were subjected to ionizing radiation process by using gamma rays. The results show improvements on the mechanical properties (compressive and flexural strength as well as modulus of elasticity) of the composites when they are irradiated at 100 and 200 kGy. Such improvements can be related with the structural modifications caused by gamma irradiation on the cellulose fibers, including changes in the morphology and the crystallinity; which were analyzed through to SEM, IR and XRD techniques

Aberrations in Incentive Learning and Responding to Heroin in Male Rats After Adolescent or Adult Chronic Binge-Like Alcohol Exposure

Background and purpose: Binge drinking is a serious problem among adolescents and young adults despite its adverse consequences on the brain and behavior. One area that remains poorly understood concerns the impact of chronic intermittent ethanol (CIE) exposure on incentive learning. Methods: Here, we examined the effects of CIE exposure during different developmental stages on conditioned approach and conditioned reward learning in rats experiencing acute or protracted withdrawal from alcohol. Two or 21 days after adolescent or adult CIE exposure, male rats were exposed to pairings of a light stimulus (CS) and food pellets for 3 consecutive daily sessions (30 CS-food pellet pairings per session). This was followed by conditioned approach testing measuring responses (food trough head entries) to the CS-only presentations and by conditioned reward testing measuring responses on a lever producing the CS and on another producing a tone. We then measured behavioral sensitization to repeated injections of heroin (2 mg/kg/d for 9 days). Results: Adolescent and adult alcohol-treated rats showed significantly impaired conditioned reward learning regardless of withdrawal period (acute or prolonged). We found no evidence of changes to conditioned approach learning after adolescent or adult exposure to CIE. Finally, in addition to producing long-term impairments in incentive learning, CIE exposure enhanced locomotor activity in response to heroin and had no effect on behavioral sensitization to heroin regardless of age and withdrawal period. Conclusions: Our work sets a framework for identifying CIE-induced alterations in incentive learning and inducing susceptibility to subsequent opioid effects