Macrophages are innate immune cells with a dynamic range of reversible activation states including the classical pro-inflammatory (M1) and alternative anti-inflammatory (M2) states. Deciphering how macrophages regulate their transition from one state to the other is key for a deeper understanding of inflammatory diseases and relevant therapies. Common regulatory motifs reported for macrophage transitions, such as positive or double-negative feedback loops, exhibit a switchlike behavior, suggesting the bistability of the system. In this review, we explore the evidence for multistability (including bistability) in macrophage activation pathways at four molecular levels. First, a decision-making module in signal transduction includes mutual inhibitory interactions between M1 (STAT1, NF-KB/p50-p65) and M2 (STAT3, NF-KB/p50-p50) signaling pathways. Second, a switchlike behavior at the gene expression level includes complex network motifs of transcription factors and miRNAs. Third, these changes impact metabolic gene expression, leading to switches in energy production, NADPH and ROS production, TCA cycle functionality, biosynthesis, and nitrogen metabolism. Fourth, metabolic changes are monitored by metabolic sensors coupled to AMPK and mTOR activity to provide stability by maintaining signals promoting M1 or M2 activation. In conclusion, we identify bistability hubs as promising therapeutic targets for reverting or blocking macrophage transitions through modulation of the metabolic environment.

Natural hybridization in Neotropical orchids is summarized, and the frequency of nothogenera in the subtribe Zygopetalinae is highlighted. A new nothogenus discovered in Costa Rica, formed by the cross between species of Benzingia and Chondroscaphe , is described, and the new nothospecies × Benzoscaphe stelleri is described and illustrated. Putative parents, as well as their derivative hybrid, are compared through composite digital plates. Cues are offered about the pollination mechanisms of the putative parents, based on the morphology of the flowers and pollinaria, which possibly led to the formation of the natural cross between different genera.

Marco Vinicio Segura-Buján, Anne Chinnock, Elvira Salas Hidalgo, Georgina Gómez

The objective of this study was to describe the amount of physical activity carried out by Costa Rican urban population and to determine its relationship to socio-demographic and anthropometric variables. A representative sample of Costa Rican urban population, made up by 798 individuals, was analyzed. The physical activity data (displacement, free time and total) were taken through the International Physical Activity Questionnaire (IPAQ). Participants were classified as active or inactive according to the internationally recommendation of physical activity. 37.1% of participants did not meet the recommendations. It was also observed that the time of physical activity was significantly longer (p< .001) in men (535.3 vs. 371.3 min/week) in younger people (584.3 min/week in the 15-19 years old group vs. 309.2 min/week in the 50-65 years old group) and in people that were not overweight (521.3 vs. 411.7 min/week). The waist circumference was significantly lower in active people (90.6 vs. 94.1 cm, p < .011), and active men also showed a lower neck circumference (38.2 vs. 39.6 cm, p < .001), lower weight (75.7 vs. 79.3 kg, p = .025) and a lower body mass index (26.1 vs. 27.9 kg/m2, p = .004). These results could be used to raise awareness on the need for improvement in the implementation of global policies and practices to promote physical activity.

Macrophages are essential innate immune cells characterized by a high diversity and plasticity. In vitro, their full dynamic range of activation profiles include the classical pro-inflammatory (M1) and the alternative anti-inflammatory (M2) program. Bistability usually arises in biological systems that contain a positive-feedback loop or a mutually inhibitory, double-negative-feedback loop, which are common regulatory motifs reported for macrophage transitions from one activation state to the other one. This switch-like behavior of macrophage is observed at four different levels. First, a decision-making module in signal transduction includes mutual inhibitory interactions between M1 (STAT1 and NF-KB/p50-p65) and M2 (STAT3 and NF-KB/p50-p50) signaling pathways. Second, a switch-like behavior at the gene expression level includes complex network motifs of transcription factors and miRNAs. Third, those changes impact metabolic gene expression leading to several switches in energy production, NADPH and ROS production, TCA cycle functionality, biosynthesis and nitrogen metabolism. Fourth, metabolic changes are monitored by specialized metabolic sensors coupled to AMPK and mTOR activity to provide stability by maintaining the signals to promote either M1 or M2 activation. The targeting of robust molecular switches has the potential to treat a broad range of widespread diseases such as sepsis, cancer or chronic inflammatory diseases.

Background: The subtribe Oncidiinae represents one of the most diverse orchid groups in Costa Rica, comprising 186 species across 33 genera. Questions: Despite their already known richness, is it possible that the diversity of less conspicuous genera remains poorly documented, especially where collecting efforts have been limited? To address the diversity of the genus, what is the most suitable circumscription of Notyliopsis? Taxa: Orchidaceae, Macroclinium geniculatum Pupulin & Bogarín, sp. nov., Notyliopsis beatricis P.Ortiz. Study sites: Reserva Biológica Guaitil, Pejibaye, Costa Rica; Calle La Mina, Tayutic, Costa Rica Results: As part of the ongoing initiative to update the Flora costaricensis: Orchidaceae, we describe a new species of Macroclinium and report the first record of Notyliopsis, both members of the Oncidiinae. Conclusions. Macroclinium geniculatum is described, illustrated, and compared with the similar M. confertum Pupulin, from which it differs in the free lateral sepals (vs. basally connate), the petals with three rose-purple blotches (vs. numerous dots), the sigmoid column (vs. straight), and the claw of the lip being geniculate at the middle (vs. straight). Notyliopsis beatricis, known only from Chocó, Colombia, is newly recorded for the Costa Rican flora. We used molecular data to reassess the phylogentic position of Notyliopsis and to test the hypothesis that Santenderella should be included within this genus. For both species, detailed morphological descriptions and illustrations based on Costa Rican specimens are provided. These findings contribute to the ongoing updating of the inventory of the Oncidiinae in the country towards the completion of Flora costaricensis.