Lead exposure and its relationship with fecal cortisol levels in black howler monkeys (Alouatta pigra).

Efficiently detecting early environmental threats to wildlife is vital for conservation. Beyond obvious dangers like habitat loss or deforestation, our study focuses on one of the most hazardous toxic metals for wildlife: lead (Pb). Pb is a widespread, cumulative, and insidious environmental pollutant that can trigger a wide range of physiological, biochemical, and behavioral disorders. In fact, Pb can cause permanent dysfunction of the major stress system, the hypothalamic pituitary adrenal (HPA) axis. We analyzed Pb and cortisol concentrations in fecal samples from Alouatta pigra in southern Mexico. Fecal samples were collected across six sites categorized as free-ranging (n = 65; conserved and disturbed) and from captive animals (n = 58). Additionally, we collected soil samples (n = 35). We found that Pb was present in 28% of fecal samples and 83% of soil samples. There was a positive relation between fecal and soil Pb levels, and fecal Pb concentration was negatively associated with cortisol levels. However, the claim of Pb being a direct interference with HPA axis requires further investigation. Given our findings, assessing wildlife exposure can be a valuable tool for understanding potential Pb exposure levels in the environment and its possible implications for human health. It can also serve as an early warning system of these consequences.

Marketing strategies for waste recycling: a bibliometric analysis towards the circular economy.

Companies have adopted green marketing and marketing strategies to position themselves in consumer preferences and combat the problem of accelerated consumption of resources that has compromised the planet's regenerative capacity, where the circular economy emerges as a solution to move towards responsible production and consumption patterns. From waste recycling marketing strategies, a descriptive analysis of 120 documents from the SCOPUS database was carried out using bibliometric techniques to know the existing state of the art for the period 1977-2021. The results indicate that the annual scientific production increased in the last ten years by over 200% for 2019, highlighting the USA, China, UK, Germany, and India, and Mexico is in position 22. The conceptual and trend analysis points out the relationship between marketing, waste management, commercialization, recycling, sustainable development, and circular economy, topics that have deepened research in the last 5 years due to the SDGs. Through intellectual analysis, schools of thought were identified, highlighting Chen, Wang, Zhang and Liu, Lu, and White as the most influential and connected with other authors. The results show no link between the study areas, but rather that they are developed in isolation, evidencing an area of opportunity to work on marketing strategies for waste recycling, where companies adopt circular economy objectives, obtaining an advantage. Competitive position and position in the market by offering products from a valorization that the consumer prefers.

Circular economy strategy and waste management: a bibliometric analysis in its contribution to sustainable development, toward a post-COVID-19 era.

A descriptive analysis of 416 documents was performed using bibliometric techniques, in order to gather existing knowledge in circular economy focusing on waste management (2007-2020). The results of this study indicate that annual scientific production increased 94% in the last 5 years, highlighting the countries of Italy, Spain, the UK, China, Brazil, and India. Between the most cited documents stand out those related to calorific value of municipal solid waste and waste to energy technologies for achieving circular economy systems. The conceptual analysis indicates strong linkage between circular economy and sustainable production, waste management, and recycling. Emerging research trends evolved from processes and industry-oriented approach (2017) toward waste management, recycling, and circular economy (2019) and sustainable development and urban solid waste (2020). The analysis reveals five dominant circular economy and waste research themes: (1) greenhouse gases; (2) circular economy, waste management, and recycling; (3) life cycle; (4) waste treatment; and (5) anaerobic digestion and recovery; trends research are related to policy interventions, and enforcement of authorities' regulations to foster circular economy transition, increase the use of practices of recycling and reusing, as well as discourage a growing consumption culture. Results found denote the challenge represented by the implementation of comprehensive policies in circular economy. The above being a key alternative for green recovery in response to the current COVID-19 pandemic.

New investigation in PVP-mediated synthesis of noble metallic nanomaterials.

As one of the most heavily used starting materials in metallic nanostructure syntheses, PVP has made a series of revolutionary successes. However, the true role of PVP still has not been fully understood. Herein, designed reactions and NMR analyses have been done to prove the redox reaction in PVP-mediated synthesis of metallic nanomaterials. As metal ions are reduced, alpha-pyrrolidone rings of PVP are partially oxidized and form poly(vinyl(pyrrolidone)x-(succinimide)y), which has a crucial surface modification capability for nanocrystals. This new finding provides insight into how PVP manipulates the structures and morphologies by modifying the reaction rate and stabilizing the nanocrystals.