Evaluation of Cr(VI) Removal from Tanning Effluents Using Magnetic Nanoparticles of Fe3O4 Synthesized with Olea europaea Bone Extract.

The tanning industry generates effluents with high chromium content, which require treatment prior to discharge into the sewage system. This article explores the use of magnetic magnetite nanoparticles (MNPs) to remove Cr(VI) from aqueous solutions, such as tanning effluents. The MNPs were synthesized by coprecipitation reaction using the Olea europaea extract as a reducing agent. Subsequently, they were characterized by dynamic light scattering spectroscopy (DLS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). MNPs with irregular morphology and diameters ranging from 73.28 to 162.90 nm were obtained. Cr(VI) removal was performed using jar test methodology, and its efficiency was evaluated in the laboratory for different initial Cr(VI) (mg/L) concentration and nanoparticle (g/L) concentration. A kinetic study was developed and indicated that the equilibrium adsorption mechanism corresponds to a pseudo-second-order model. Furthermore, the isotherm analysis revealed that chromium adsorption best fits the Langmuir isotherm. Finally, Cr(VI) removal rates from 85% to 100% were achieved in tanning and retanning effluents.

Portrayal of Women as Physicians in Movies, 1990-2020.

This cross-sectional study quantifies the portrayal of women as physicians in US movies over the past 3 decades.

Effects of Elbow Crutch Locomotion on Gluteus Medius Activation During Stair Ascending.

Crutches can help with the locomotion of people with walking disorders or functional limitations. However, little is known about hip muscle activation during stair ascending using different crutch locomotion patterns in people without disorders and limitations. Thus, we determined the acute effects of elbow crutch locomotion on gluteus medius (GM) activity during stair ascending. This comparative analytic cross-sectional study enrolled ten healthy men (22.0 ± 0.47 years). Participants climbed up the stairs with elbow crutches using one or two crutches, with ipsilateral or contralateral use, and after loading or unloading a limb. EMG signals were recorded from anterior, middle, and posterior portions of the GM and compared between the crutch conditions. The Kruskal-Wallis test and Dunn's multiple comparison test were performed (α = 5%). The activation of the GM increased with the ipsilateral use of crutches, with two crutches and three points, and when all the load depended only on one limb. GM activation decreased with contralateral use and in the unload limb. In conclusion, ascending stairs with elbow crutches alters the GM activation. The more critical factors were choosing the crutches' lateral use, the number of crutches, and if the limb is loaded or unloaded while ascending the stairs. Our findings can be helpful to increase or decrease the GM activation for those who use or will use crutches.

Morally injurious experiences and meaning in Salvadorian teachers exposed to violence.

Helping professionals working to alleviate the effects of violence and injustice can confront morally injurious experiences (MIE) that violate deeply held moral values/beliefs, placing them at risk for burnout and trauma-related problems (e.g., posttraumatic stress disorder [PTSD]). Focusing on 257 teachers from educational departments throughout El Salvador, we incorporated structural equation modeling (SEM) to examine (1) whether exposure to MIEs for this population (e.g., betrayal, witnessing harm to an innocent student) are directly linked with higher PTSD symptomatology and work-related burnout and (2) whether MIEs contribute to these outcomes via meaning made of trauma. SEM results revealed that MIEs were in fact uniquely linked with PTSD symptoms and burnout, above and beyond rates of direct victimization and demographic factors. In addition, greater MIEs were indirectly linked with study outcomes via the extent to which teachers were able to make meaning of their identified stressors. These findings support the importance of screening for MIEs among helping professionals and also suggest that meaning making could serve as a central mediating factor for how MIEs contribute to trauma-related problems among persons working to promote peace and justice in the world.

Event centrality and posttraumatic outcomes in the context of pervasive violence: a study of teachers in El Salvador.

It is well established that the importance assigned to a trauma can affect one's recovery and psychological health in numerous ways. Event centrality is an increasingly popular construct that captures the tendency among survivors to reevaluate and possibly accommodate their worldviews posttrauma. The centrality given to trauma appears to serve as a "double-edged sword" in that this construct might factor prominently in both posttraumatic stress disorder (PTSD) and posttraumatic growth (PTG). Focusing on 257 violence-exposed teachers from educational departments throughout El Salvador, we examined whether the centrality assigned by the teachers to stressful life events uniquely predicted both PTSD symptomatology and PTG. Results revealed that event centrality was positively related to both PTSD and PTG, even when controlling for demographic factors, violence exposure, and depression. In addition, PTSD symptomatology and PTG were not associated with one another in this sample. In summary, these findings support the role of event centrality as a contributing factor for PTSD and PTG among persons exposed to pervasive trauma.

Evolución y tendencia secular de la talla en el Departamento de Guatemala de 1936 a 1995 / Evolution and secular trend in the height in the Departament of Guatemala from 1936 to 1995

Objetivo. Describir la tendencia de la talla en guatemaltecos hombres y mujeres, avecindados en el municio de Guatemala en los quinquenios de 1936 a 1995. Diseño. Descriptivo, retrospectivo. Población, Cuatromil novecientos hombres y mujeres de 18 a 20 años. Metodología. La muestra fue estratificada en quinquenios y los casos de cada estrato se tomaron en forma aleatoria sistemática, dividiendo el número de inscritos por quinquenios entre la muestra deseada. La talla se midió en escala numérica contínua y para determinar la varianza se realizó previamente un estudio piloto que incluyó a 140 personas distruibuídas proporcionalmente en cada quinquenio; se determinó que la desviación estandar fue de 6.31 cms. para mujeres y 7.11 cms. para hombres. La muestra calculada para cada estrato significó una representatividad superior al 98 por ciento. Resultados. La evolución y tendencia de la talla fue de aumento para ambos sexos. La talla promedio para mujeres en 1936 era de 149.3 cms, aumentando 7.1 cms; obteniendo una talla promedio de 156.4 en l995. En hombres la talla promedio inicial fue de 162 cms. aumentando 6.4 cms. para obtener una talla promedio de 168.4 cms. en 1995. Conclusiones. El aumento de la talla en los guatemaltecos en el período de 1936 a 1995 (60 años) fue de 1 cm. promedio por década