An exponential equation of state of dark energy in the light of 2018 CMB Planck data

The dynamics of the Universe is analyzed using an exponential function for the dark energy equation of state, known as Gong-Zhang parameterization. The phase space of the free parameters presented in the model is constrained using Cosmic Microwave Background radiation, Cosmic Chronometers, modulus distance from Hydrogen II Galaxies, Type Ia Supernovae and measurements from Baryon Acoustic Oscillations, together with a stronger bound from a Joint analysis. The cosmological model is confronted with $\Lambda$CDM, observing there is a strong evidence for $\Lambda$CDM in the Joint analysis although the exponential model is preferred when the data are separated. Based on the Joint analysis, a value of $\omega_0 = -1.202^{+0.027}_{-0.026}$ is found for the characteristic parameter presented in the equation of state. Additionally, the cosmographic parameters at current times are reported, having $q_0 = -0.789^{+0.034}_{-0.036}$, $j_0=1.779^{+0.130}_{-0.119}$, and a transition deceleration-acceleration redshift $z_T = 0.644^{+0.011}_{-0.012}$. Furthermore, the age of the Universe is estimated as $t_U = 13.788^{+0.019}_{-0.019}$ Gyrs. Finally, we open a discussion if this model could alleviate the $H_0$ and $S_8$ tensions.Comment: Accepted in Physics of Dark Univers

Ecological and socioeconomic aspects of meliponiculture in the Yucatan Peninsula, Mexico

Objective: Describe the main economic and ecological characteristics in the production of crops of native stingless bees (NSB) in the Yucatan peninsula (YP), Mexico. Design/methodology/approach: Through the snowball method, an exhaustive search for references on meliponiculture was carried out, using keywords individually or in combination, such as meliponiculture, Melipona, native stingless bee, Mayan meliponiculture, Yucatan peninsula, etc. Results: In Campeche and Yucatán there are a total of 216 producers who have a total of 3362 jobones destined for meliponiculture. However, economic and ecological studies are scarce and do not allow to know in depth the benefits of NSB in the YP, that is, information on production costs and economic spillover that would be obtained with the preservation of the NSB. Limitations on study/implications: This study describes the socioeconomic and ecological aspects of native stingless bees in the Yucatán peninsula, México. Findings/conclusions: Meliponiculture is an important activity from the cultural aspect, therefore its rescue and conservation is urgent; on the other hand, the selling cost of Melipona honey is higher compared to honey from the bee Apis mellifera L., being an economic alternative for producers in rural communities.Objective: To describe the main economic and ecological characteristics in the production of native stingless bees (NSBs) in the Yucatan Peninsula (YP), Mexico. Design/Methodology/Approach: Through the snowball method, an exhaustive search for references about meliponiculture was conducted, using keywords individually or combined, such as meliponiculture, Melipona, native stingless bees, Mayan meliponiculture, Yucatan Peninsula, etc. Results: In Campeche and Yucatán there is a total of N=216 producers who own a total of 3,362 “jobones” destined to meliponiculture. However, economic and ecological studies are scarce and do not allow deeply understanding the benefits of NSBs in the YP; that is, information about production costs and economic benefits that would be obtained with the conservation of NSBs. Study Limitations/Implications: This study describes the socioeconomic and ecological aspects of native stingless bees in the Yucatan Peninsula. Findings/Conclusions: Meliponiculture is an important activity from the cultural aspect, therefore, its rescue and conservation is urgent; on the other hand, the sale cost of Melipona honey is higher compared to honey from the Apis melifera L. bee, representing an economic alternative for the producers of rural communities