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Premise: Recent phylogenetic studies of the Araceae have confirmed the position of the duckweeds nested within the aroids, and the monophyly of a clade containing all the unisexual flowered aroids plus the bisexual-flowered Calla palustris. The main objective of the present study was to better resolve the deep phylogenetic relationships among the main lineages within the family, particularly the relationships between the eight currently recognized subfamilies. We also aimed to confirm the phylogenetic position of the enigmatic genus Calla in relation to the long-debated evolutionary transition between bisexual and unisexual flowers in the family., Methods: Nuclear DNA sequence data were generated for 128 species across 111 genera (78%) of Araceae using target sequence capture and the Angiosperms 353 universal probe set., Results: The phylogenomic data confirmed the monophyly of the eight Araceae subfamilies, but the phylogenetic position of subfamily Lasioideae remains uncertain. The genus Calla is included in subfamily Aroideae, which has also been expanded to include Zamioculcadoideae. The tribe Aglaonemateae is newly defined to include the genera Aglaonema and Boycea., Conclusions: Our results strongly suggest that new research on African genera (Callopsis, Nephthytis, and Anubias) and Calla will be important for understanding the early evolution of the Aroideae. Also of particular interest are the phylogenetic positions of the isolated genera Montrichardia, Zantedeschia, and Anchomanes, which remain only moderately supported here., (© 2023 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

The bronchoconstrictor effect of intravenous substance P can be antagonised by atropine pre-treatment in several species, and we have previously reported this finding in anaesthetised sheep. In the present study, we have assessed the effect of cooling the right vagus after sectioning the left vagus (n = 6), and bilateral vagotomy (n = 7) on the bronchoconstrictor response to a single intravenous dose of substance P (SP) (0.3-1.0 mumol/kg) in anaesthetized female sheep aged 6 to 12 months. Respiratory parameters including tidal volume, flow and transpulmonary pressure pressure were measured, from which pulmonary resistance (RL; cmH2O.1(-1).s) and dynamic compliance (CDyn; ml.cmH2O(-1) were calculated. Systemic arterial pressures were also measured. Vagal cooling significantly attenuated the bronchoconstrictor response to SP at 7 degrees C (RL P < 0.01; Cdyn P < 0.001). A further reduction in the response to SP occurred at 3 degrees C, but this was not statistically significantly different from the response at 7 degrees C. Vagotomy abolished the response to SP. SP caused mild, but statistically insignificant, hypotension (119.7 vs. 107.7 mmHg). These results suggest SP causes bronchoconstriction in the anaesthetised sheep by vagal reflex mechanisms, involving stimulation of myelinated nerve fibre endings.

The in vivo effects of substance P (SP) on respiratory parameters in four different age groups of sheep were examined. Intravenous SP (10(-8) to 5 x 10(-6) mol kg-1 bodyweight) caused a dose-dependent reduction in dynamic compliance and increase in respiratory resistance in all four groups. The bronchoconstrictor response was age-related, with the greatest response occurring in the youngest age group (four to six months). In the oldest group (over four years) there was minimal bronchomotor response to SP, but a dose-dependent apnoea was present. These findings indicate that there is an age-related alteration in the respiratory response to SP in sheep.

Respiratory function in the restrained, conscious domestic fowl was measured using a non-invasive technique and computer aided analysis to examine respiratory flow, and in-dwelling arterial catheters to monitor blood carbon dioxide levels. The effects of two low ranges of inspiratory carbon dioxide (0.2 to 1.0 per cent and 0.25 to 2.25 per cent) were studied, simulating levels of carbon dioxide that may occur in commercial poultry units and representing a mild environmental stress for the birds. A linear increase in minute volume with inspiratory carbon dioxide was observed, due primarily to increases in tidal volume. Arterial carbon dioxide (PaCO2) tension also rose as the inspiratory carbon dioxide concentration was raised, but higher inspiratory carbon dioxide levels were required to affect significantly blood carbon dioxide concentration than to modify respiratory parameters. Variation was observed in the individual bird's response to carbon dioxide (bird X carbon dioxide interaction), suggesting that resting values of the respiratory parameters measured were important in determining the bird's ventilatory response to carbon dioxide.

The influence of vagotomy on resting arterial blood gases (PaCO2 and PaO2) and on the ventilatory responses to hypercapnia and hypoxia was studied in three different species of anaesthetized animals. After bilateral cervical vagotomy resting PaCO2 generally declined. In the dog, where this was studied more fully, resting PaCO2 declined significantly (8-13 +/- 0-67 mm Hg) over several hours, but PaO2 changes were not significant. After vagotomy tidal volume (VT), but not frequency (f), increased with increasing chemical drive. It is concluded that the increase in frequency in response to increased CO2 or decreased O2 is dependent on the vagal mechanisms. Minute volume, fractional inspiratory CO2 (VE, FICO2) and minute volume, fractional inspiratory O2 (VE, FIO2) relationships have been determined. Although vagotomy may not decrease the response of minute volume of ventilation in the lower part of VE, FICO2 curves (mild hypercapnia), it flattened the upper parts of the curves in sheep and rabbits, and to a lesser extent in dogs; it seemed that there was little species difference in this respect. Ventilatory responses to graded hypoxia were close to or slightly higher than pre-vagotomy values throughout the VE, FIO2 curves in all animals.

Several respiratory parameters were measured in five groups of hens to estimate the variation in respiratory function of the general hen population. A non-invasive technique was used to measure respiratory flow, with computer-aided analysis of the data, and the results were examined statistically. Using different groups of hens, additional information was obtained regarding possible sources of variation between individual hens, such as egg laying condition, age and health. Significant differences between individuals within the groups were observed, but there were also changes in breath-to-breath variation for individual hens. While some changes in the variation between birds were observed from one group to another, variation within individual birds made interpretation of the results difficult. Repeated measurements made on one group revealed significant changes in minute volume with time, but the changes were not related to learning. Significant interactions between hens and time of measurement occurred for certain parameters, showing that the individuals' responses changed with time in different ways. The groups of hens were compared to observe whether they represented the same or distinct populations, and were found to overlap to varying extents for different respiratory parameters. Single respiratory variables and weighted combinations of certain variables were also used to separate the groupings, as a possible diagnostic method for partitioning groups of hens.

The ventilatory and cardiovascular effects of i.v. administration of the respiratory stimulants etamiphylline and almitrine were investigated in conscious or decerebrate adult female domestic fowl. Infusion of etamiphylline (100 mg . kg-1) or injection of almitrine (2 mg . kg-1) evoked a potent long-lasting stimulation of ventilation in both conscious and decerebrate fowl. The pattern of the respiratory response was characteristically different to that observed in mammals in that the increased minute volume of ventilation was attained by large increases in respiratory frequency accompanied by a reduction in tidal volume. The pattern of respiration following drug-induced stimulation was, in some birds, typical of thermal panting although neither etamiphylline nor almitrine caused significant increases in body temperature. Differences in the pattern of responses of the rate and depth of breathing may be attributed in part to the differences in pulmonary receptor systems involved in the control of breathing in birds and mammals.