Caracterización química de los volátiles de Tagetes nelsonii

Species of the genus Tagetes (Astereceae) have shown important medicinal and biological properties.  Many Tagetes species are native from Mexico, however, there are few studies on their volatiles. The objective of the present study is to characterize the volatiles of Tagetes nelsonni Greenm commonly known as “Chik chawa”, which is a plant used in some regions of Chiapas State, Mexico for medicinal purposes.  Our work was focused to extract and to identify the T. nelsonii volatiles using Solid Phase Microextraction (SPME) and Gas Chromatography-Mass Espectrometry (GC-MS) respectively. The compounds identified are a mixture of terpenes.  The major volatile components are (E)-β-tagetone (43-9%) and dihydrotagetone (20.7%), followed by trans-β-ocimene, eucaliptol, limonene and β-cubebene. Tagetes nelsonni contains fragant compounds as α and β-pinene, trans-β-ocimene, limonene, linalool, (E) and (Z)-tagetones, dihydrotagetone and cis and trans-tagetenone with potential to be used for cosmetic, pharmaceutical purposes and to help to control insect pest of plant problems.Especies del género Tagetes (Asteraceae) han mostrado tener propiedades medicinales y biológicas muy importantes. Muchas especies de Tagetes son nativas de México, sin embargo, existen pocos estudios sobre la caracterización de sus volátiles.  El objetivo del presente trabajo es caracterizar químicamente los volátiles de Tagetes nelsonii comúnmente conocida como “Chik chawa”, la cual es una planta utilizada en algunas regiones del estado de Chiapas, México para fines medicinales. La pregunta es que si las hojas de T. nelsonii son ricas en compuestos fragantes con propiedades medicinales. Los volátiles de T. nelsonii fueron extraídos e identificados utilizando las técnicas de Microextracción en Fase Sólida y Cromatografía de gases acoplada a Espectrometría de masas (GC-MS) respectivamente.  Los compuestos emitidos por T.  nelsonii son una mezcla de compuestos terpénicos. Los compuestos mayoritarios son (E)-tagetona (43-9%) y dihidrotagetona (20.7%), seguidos por trans-β-ocimeno, eucaliptol, limoneno y β-cubebeno. T. nelsonii contiene compuestos fragantes como, α y β-pineno, trans-β-ocimeno, limoneno, linalool, tagetonas, dihidrotagetona y tagetenonas con potencial para ser usados como cosméticos y farmacéuticos y para resolver problemas de plagas de insectos de las plantas como repelentes. &nbsp

Biomass Accumulation and Carbon Storage in Pinus maximinoi, Quercus robur, Quercus rugosa, and Pinus patula from Village- Forests of Chiapas, Mexico

The Frailesca region (Chiapas, Mexico) presents a lack of forest studies and its environmental contribution. This chapter displays a first case study with preliminary research information regarding the identification of main forest trees and rural villages with best potential for biomass production and carbon storage management. Twenty two plots of 500 m2 were selected in 11 villages of the region, in order to identify the main and dominant forest trees species and then to estimate the biomass production and carbon storage in pine (Pinus maximinoi), oak (Quercus robur), holm oak (Quercus rugosa) and Mexican weeping pine (Pinus patula) species. This study shows that the largest accumulation of both biomass and carbon occurred in the pine forests and the lowest in the oak forests. Pine trees showed carbon storage of 516.75 Mg ha−1, followed by holm oaks, with 297.21 Mg ha−1; the species with the lowest value was oak, with 75.02 Mg ha−1. The forests of the 24 de Febrero villages had the highest potential for carbon storage. Deep studies are being conducted in relation to the aboveground biomass, carbon contents in trees stem, branches and leaves, and the relation to biomass dynamics and carbon stocks and other ecological aspects of village-forests

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Fighting ability and the toxicity of raiding pheromone in an obligate kleptoparasite, the stingless bee Lestrimelitta niitkib

Abstract The evolution of obligate kleptoparasitism, the theft of food, has led to remarkable innovations, including physical weapons and chemical signals that can evolve into chemical weapons. Stingless bees in the genus Lestrimelitta are excellent examples of this phenomenon because they are obligate kleptoparasites that no longer collect floral resources and instead steal brood resources from other bees. Their ability to raid successfully is thus essential to their fitness even when they fight species that are physically bigger, have larger defense forces, or both. We conducted morphometric analyses, quantified Lestrimelitta niitkib mandibular gland pheromone (MGP) components, and carried out individual fighting trials between L. niitkib and the stingless bee Scaptotrigona mexicana, a common victim species, to shed light on the detailed reasons for their success at robbing. Measurements showed that L. niitkib mandibles have thicker exoskeleton cuticles and overall greater width, particularly in the medial and proximal sections, than S. mexicana, which is quite similar in body size. In all fights, L. niitkib bit victims and released MGP, as it does during raids. Scaptotrigona mexicana victims exhibited significantly increased uncoordinated behaviors and showed partial or complete paralysis. We analyzed and quantified the major components of MGP, which consisted of large quantities of geranial (mean of 253 μg) and neral (48 μg) per bee. Microinjections of 1 bee equivalent (BE) of natural or synthetic MGP and ≥ 0.1 BE of geranial significantly increased deleterious behaviors and paralysis as compared to control injections. We suggest that the large quantities of MGP used during raiding have led to an unexpected outcome, a semiochemical evolving the additional function of a toxin, and contribute to the ability of Lestrimelitta to rob its victims. Significance statement Kleptoparasites, organisms that steal food resources, employ multiple physical and chemical tools to survive. The success of kleptoparasitism requires a balance between honesty and coercion in interspecific communication. The genus Lestrimellita consists of a group of kleptoparasitic stingless bee species that raid other bee colonies for food and therefore depend upon winning these raids. However, why they succeed remains not fully understood. We studied differences in morphology between L. niitkib and its victims, the pheromones they release during raids, and ran individual fight trials between L. niitkib and a common victim to identify why they are successful. We suggest that the release of pheromones at the beginning of raids, in concert with the pheromone’s toxicity, has been combined to improve L. niitkib’s ability to successfully rob

Melipona beecheii (Hymenoptera, Apidae) foragers deposit a chemical mark on food to attract conspecifics

Stingless bees have a sophisticated system of chemical communication that helps conspecifics find food sources. In this study, we investigated whether Melipona beecheii foragers deposit a chemical mark on food to recruit conspecifics. Our results showed that foragers preferred to visit the feeders visited previously by conspecifics over clean feeders. We also found that foragers preferred visiting feeders baited with labial gland extracts over those baited with mandibular extracts or hexane. Labial gland extracts elicited higher forager antennal responses compared with those evoked by the mandibular gland extracts or hexane. Labial gland extracts and extracts from feeders visited by foragers contain a mixture of unsaturated hydrocarbons, followed by straight chain hydrocarbons and small quantities of esters. The main component is a mixture of alkene isomers C27:1

Gene Flow from Wild to Managed Colonies in the Stingless Bee Scaptotrigona Mexicana and an Update on its Mating Frequency

Abstract Researchers have hypothesized that wild stingless bee colonies are a repository of genes for managed populations via the mating of managed virgin queens with males from wild colonies. We tested this hypothesis with the stingless bee, Scaptotrigona mexicana, a culturally important species in the study region. Each of ten colonies were split into two colonies and placed in a meliponary, which resulted in ten queen-right mother colonies and ten queenless daughter colonies. We allowed daughter colonies to produce gynes, which then naturally mated with males of unknown origins. Six months later, five third-instar larvae from each colony were genotyped at six microsatellite loci. Four new alleles (12% of 33 alleles) were found in daughter colonies that were not present in any other mother colony. The Fst index showed no overall significant differences between mother and daughter colonies, indicating that they belonged to the same population despite the new alleles. Interestingly, nine queens were estimated to be polyandrous, with an average mating frequency of 1.3, unlike previous reports for this species. These results have implications for the fitness of managed stingless bee colonies and suggest that a better understanding of how gene flow is affected by human management practices would be beneficial