Juana Perez

Simple Summary: The present study evaluates the effects of two dietary supplements (guanidinoacetic acid [GAA] and zilpaterol hydrochloride [ZLH]) on the productive performance of fattening lambs over a 60-day period. The inclusion of these additives did not result in significant differences in the parameters studied. However, serum glucose and creatinine levels in the GAA group were higher than those in the control group. These findings suggest that further research is needed to determine the optimal dosage and duration of GAA supplementation to enhance lamb growth and meat production. Abstract: This study evaluated the effects of dietary supplementation with guanidinoacetic acid (GAA) and zilpaterol hydrochloride (ZLH) on productive performance, carcass traits, and blood chemistry in non-castrated male lambs over 60 days. Twenty-four Pelibuey × Dorper crossbred lambs (16.3 ± 2.7 kg) were adapted to housing and diet for 14 days before being randomly assigned to one of three treatments: (1) Control: total mixed ration (TMR) without additives; (2) GAA: TMR with 0.2% GAA; and (3) ZLH: TMR with 6 mg/kg dry matter (DM) of ZLH for the last 30 days. No significant differences were observed in productive performance or carcass traits among treatments. However, lambs fed GAA showed higher serum glucose and creatinine levels than the control group (p < 0.05), suggesting a potential effect on energy metabolism. ZLH supplementation had no measurable impact on the parameters evaluated. These findings indicate that while GAA may influence certain metabolic indicators, further research with extended feeding periods or varying dosages is needed to clarify its effects on growth and carcass characteristics in lambs.

The construct of the self is important in the domain of memory research. Recent work has shown that person memory is influenced by similarity of social targets to the self. The current experiments investigate self-similarity as defined by traits and political ideology to better understand how memory for social targets is organised. Across three experiments, participants formed positive or negative impressions based on each target’s picture, a trait-implying behavior (Experiments 1 & 2), and/or political ideology (conservative/liberal label in Experiment 2; political-ideological belief statements in Experiment 3) followed by a memory test. Results showed a self-similarity effect dependent on valence in Experiment 1, but not in Experiments 2 or 3 when participants processed ideological information associated with targets. These results suggest that self-similarity has an effect on memory for social targets, but that ideological information disrupts self-focused processing of others, suggesting that ideological information also has a powerful influence on what people remember about others (i.e. social targets).

The pandemic outbreak in March 2020 and its associated sanitary regulations and restrictions triggered an abrupt and significant change for society in general and for families’ organization in particular. In Chile, the Santiago Metropolitan District was under a strict lockdown that involved the closure of the entire educational system. From a systemic-family stress perspective, the impact of these changes might have consequences not only for each individual family member, but for the parental dynamic and, consequently, for children’s well-being. This paper presents the results of a follow-up study showing changes in self-reported parental depression and the perceived home organization of mothers and fathers assessed at three different moments: before the pandemic, at the initial outbreak, and after 1 month of strict lockdown. Relevant moderators were explored using linear mixed models to understand the within-subject changes in mothers’ and fathers’ self-reports across the different assessment times. Financial strain, personality traits of self-criticism and dependency, previous parent–child quality interaction, recent major stressful events, and number of children are highlighted as relevant factors that moderate changes in home chaos and parental mental health perception. Significant risks and protective factors are described for fathers and mothers. The use of pre-pandemic measures as baseline levels enabled the identification of personal and family characteristics that were related to better outcomes. The results help increase our understanding of the sanitary regulations’ impacts on the family system and identify vulnerability indicators that should be considered.

La agroecología tiene como objetivo el conocimiento de los elementos y procesos claves en el funcionamiento de los agrosistemas, para su eficaz gestión en armonía con el ambiente. La protección vegetal ha sido enfocada tradicionalmente, bajo el concepto de lucha y control, utilizando arsenales químicos o biológicos y, en estos momentos, biotecnológicos. La aplicación de criterios ecológicos en protección vegetal ha permitido desarrollar procesos como la biofumigación, fundamentada en la utilización de los gases resultantes de la biodescomposición de la materia orgánica para el manejo de organismos patógenos de los vegetales. Es de esperar que el futuro de la agricultura muestre una mayor preocupación por el ambiente, la conservación de los recursos naturales, la salud de las personas y se destaque su contribución a la reducción de la pobreza, así como su aportación al desarrollo de los agrocombustibles.