A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales

The Caryophyllales constitute a major lineage of flowering plants with approximately 12500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world

Augmented leg vasoconstriction in dynamically exercising older men during acute sympathetic stimulation

Vasoconstrictor responsiveness to acute sympathetic stimulation declines with advancing age in resting skeletal muscle. The purpose of the present study was to determine if age-related reductions in sympathetic vasoconstrictor responsiveness also occur in exercising skeletal muscle. Thirteen younger (20–30 years) and seven older (62–74 years) healthy non-endurance-trained men performed cycle ergometer exercise at ∼60 % of peak oxygen uptake while leg blood flow (femoral vein thermodilution), mean arterial blood pressure (radial artery catheter), and plasma adrenaline and noradrenaline concentrations were measured. After steady state was reached (i.e. ∼4 min), acute sympathetic stimulation was achieved by immersing a hand in ice water for 2–4 min (cold pressor test, CPT). CPT tended to cause a larger increase in mean arterial blood pressure in older men (older (O): 16 ± 3 mmHg; younger (Y): 10 ± 2 mmHg) during exercise, but increases in arterial noradrenaline were similar (O: 2.56 ± 0.96 nM; Y: 1.98 ± 0.40 nM). However, the older men demonstrated a larger percentage reduction in exercising leg vascular conductance (leg blood flow/mean arterial pressure) during CPT compared to younger men (O: -13.6 ± 3.1%; Y: -1.5 ± 4.3%; P = 0.04). Leg blood flow tended to increase in the younger men, but not in the older men (P = 0.10). These results suggest, in contrast to what has been observed in resting skeletal muscle, that vasoconstrictor responsiveness to sympathetic stimulation is not reduced, but may be augmented in exercising muscle of healthy older humans. This could reflect a reduced ability of local substances (e.g. nitric oxide) to impair vasoconstriction in response to sympathetic stimulation during exercise in older humans

Sympathetic chemoreflex responses in obstructive sleep apnea and effects of continuous positive airway pressure therapy.

BACKGROUND: Sympathetic nerve activity is increased in awake and regularly breathing patients with obstructive sleep apnea (OSA). Over time, repetitive hypoxic stress could alter sympathetic chemoreflex function in OSA. METHODS: We determined the responses to acute hypoxia (fraction of inspired oxygen of 0.1, for 5 min), static handgrip exercise, and the cold pressor test (CPT) in 24 patients with OSA (age, 50 +/- 3 years [mean +/- SEM]; apnea-hypopnea index, 47 +/- 6 events per hour) and in 14 age- and weight-matched nonapneic control subjects. Muscle sympathetic nerve activity (MSNA) [peroneal microneurography], BP, and ventilation were monitored. RESULTS: Basal MSNA was higher in OSA patients compared to control subjects (45 +/- 4 bursts per minute vs 33 +/- 4 bursts per minute, respectively; p \u3c 0.05). Furthermore, compared to control subjects, the MSNA responses to hypoxia were markedly enhanced in OSA (p \u3c 0.001). Whereas the ventilatory responses to hypoxia tended to be increased in OSA (p = 0.06), the BP responses did not differ between the groups (p = 0.45). The neurocirculatory reflex responses to handgrip exercise and to the CPT were similar in the two groups (p = not significant). In OSA patients who were retested after 1 to 24 months of continuous positive airway pressure (CPAP) therapy (n = 11), basal MSNA (p \u3c 0.01) and the responses of MSNA to hypoxia (p \u3c 0.01) decreased significantly, whereas the ventilatory responses remained unchanged (p = 0.82). CONCLUSION: These data suggest that the sympathetic responses to hypoxic chemoreflex stimulation are enhanced in OSA and may normalize in part following CPAP therapy