Photosynthetic responses to carbon dioxide concentration can provide data on a number of important parameters related to leaf physiology. Methods for fitting a model to such data are briefly described. The method will fit the following parameters: V(cmax), J, TPU, R(d) and g(m)[maximum carboxylation rate allowed by ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco), rate of photosynthetic electron transport (based on NADPH requirement), triose phosphate use, day respiration and mesophyll conductance, respectively]. The method requires at least five data pairs of net CO(2) assimilation (A) and [CO(2)] in the intercellular airspaces of the leaf (C(i)) and requires users to indicate the presumed limiting factor. The output is (1) calculated CO(2) partial pressure at the sites of carboxylation, C(c), (2) values for the five parameters at the measurement temperature and (3) values adjusted to 25 degrees C to facilitate comparisons. Fitting this model is a way of exploring leaf level photosynthesis. However, interpreting leaf level photosynthesis in terms of underlying biochemistry and biophysics is subject to assumptions that hold to a greater or lesser degree, a major assumption being that all parts of the leaf are behaving in the same way at each instant.
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http://dx.doi.org/10.1111/j.1365-3040.2007.01710.x | DOI Listing |
PLoS One
January 2025
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan.
Background: Chronic respiratory failure (CRF) is a critical complication in patients with chronic obstructive pulmonary disease (COPD) and is characterized by an increase in the arterial-alveolar oxygen gradient (A-aDO2). The long-term trajectory and prognostic significance remain unclear. This study aimed to assess the prognostic impact of A-aDO2 and elucidate its trajectory over ten years.
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January 2025
Department of Physiology and Biochemistry, Faculty of Physical Education and Sport Science, Wroclaw University of Health and Sport Sciences, Wroclaw, Poland.
The purpose of this study was to determine the effective warm-up protocol using an added respiratory dead space (ARDS) 1200 ml volume mask to determine hypercapnic conditions, on the swimming velocity of the 50 m time trial front crawl. Eight male members of the university swimming team, aged 19-25, performed three different warm-up protocols: 1) standardized warm-up in water (WUCON); 2) hypercapnic warm-up in water (WUARDS); 3) hypercapnic a 20-minute transition phase on land, between warm-up in water and swimming test (RE-WUARDS). The three warm-up protocols were implemented in random order every 7th day.
View Article and Find Full Text PDFEur J Pediatr
January 2025
Neonatal Intensive Care Centre, St George's University Hospitals NHS Foundation Trust, London, SW17 0QT, UK.
To assess respiratory changes after neurally adjusted ventilatory assist (NAVA) initiation in preterm infants with evolving or established bronchopulmonary dysplasia (BPD). Premature infants born less than 32 weeks gestation with evolving or established BPD initiated on invasive or non-invasive (NIV) NAVA were included. Respiratory data: PCO and SpO₂/FiO₂ (S/F) ratio before and at 4, 24, 48 h post-NAVA initiation were collected.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Aramco Americas, Boston Research Center, Cambridge, MA, 02139, USA.
Membrane-based gas separation provides an energy-efficient approach for the simultaneous CO and HS removal from sour natural gas. The fluorinated polyimide (PI) membranes exhibited a promising balance between permeability and permselectivity for sour natural gas separation. To further improve the separation efficiency of fluorinated PI membranes, a melamine-copolymerization synthetic approach is devised that aims to incorporate melamine motifs with high sour gas affinity into the structure of the PI membranes.
View Article and Find Full Text PDFACS Electrochem
January 2025
Stephenson Institute for Renewable Energy (SIRE) and the Department of Chemistry, University of Liverpool, Liverpool L69 7ZF, United Kingdom.
Carbon dioxide electroreduction does not occur on Au when metal cations are absent from the electrode surfaces. Here we show that the electroreduction can be enabled without metal cations, albeit with low efficiency, by the presence of cationic surfactants on Au. The findings demonstrate that in addition to possibly stabilizing CO reduction intermediates the presence of surfactants plays a role in suppressing the competing reactions.
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