Veratrum californicum is a rich source of steroidal alkaloids such as cyclopamine, a known inhibitor of the Hedgehog (Hh) signaling pathway. Here we provide a detailed analysis of the alkaloid composition of V. californicum by plant part through quantitative analysis of cyclopamine, veratramine, muldamine and isorubijervine in the leaf, stem and root/rhizome of the plant. To determine if additional alkaloids in the extracts contribute to Hh signaling inhibition, we replicated the concentrations of these alkaloids observed in extracts using commercially available standards and compared the inhibitory potential of the extracts to alkaloid standard mixtures using Shh-Light II cells. Alkaloid combinations enhanced Hh signaling pathway antagonism compared to cyclopamine alone, and significant differences were observed in the Hh pathway inhibition between the stem and root/rhizome extracts and their corresponding alkaloid standard mixtures, indicating that additional alkaloids present in these extracts contribute to Hh signaling inhibition.

Balandra, one of the most popular beaches in La Paz, Baja California Sur, was declared a flora and fauna protection area in 2012 and, in 2021, was declared the best beach in Mexico. More recently, it was included among the ten most beautiful beaches in the world. Currently, this beach faces overcrowding. Formulating effective management policies depends, to a certain extent, on the knowledge of their recreational value and visitor characteristics. Recreational value allows us to know the benefits of the tradeoffs among the ecosystem services and society and exhibit the value of possible damages to marine ecosystems. Like the one caused in 2022 by the fire of a tourist boat inside Balandra. Using the individual travel cost method and applying 159 questionnaires to site visitors, four models were estimated to calculate the individual willingness to pay for accessing Balandra, which ranges between 3.86 and 10.38 US$/day/visitor. Recreational economic value (REV) for Balandra was estimated using two essential criteria. One, total of visitors registered in 2021. Two, daily maximum carrying capacity. We also calculated the REV as a proxy of the welfare loss derived from the site's closure. Finally, possible environmental and economic policy instruments that could be implemented are discussed.

According to the International Union for Conservation of Nature Red List, the scalloped hammerhead (Sphyrna lewini) is a critically endangered species, primarily due to intense fishing and other anthropogenic effects such as pollution. Nowadays, plastic debris contamination is a subject of concern due to its extensive presence in the sea and the digestive tracts of many fish species. The possible effects of plastic debris as a vector of other pollutants are still unknown. We analyzed the digestive tract of hammerhead sharks to investigate the correlation between plastic and other anthropic debris contamination and feeding habits in the eastern region of the Gulf of California. A total of 58 specimens were analyzed from the coastal area, revealing a plastic occurrence frequency of 79.3%. Of these, 91.4% corresponded to fibers, and 8.6% to fragments. The composition of the polymers was primarily cellulose (64.4%). According to their diet, these organisms exhibit benthopelagic habits, feeding both in the water column and on the seabed. These results indicate a high level of contamination of anthropogenic cellulosic microfibers in the area. This changed according to the year, indicating that the anthropic debris ingestion is related to the discharges of human activities and their seasonality rather than to a selection process by the sharks. Although cellulosic microfibers are recognized as a biomaterial, they can harm marine species, posing an additional threat to this iconic shark.