Point of care ultrasound measurement of paralumbar caudal vena cava diameter and caudal vena cava to aortic ratio in hypovolemic dogs.

Background: Accurate assessment of intravascular volume is critical for precise fluid prescription. In people, bedside or point of care ultrasound is used to measure the inferior vena cava, with or without paired aortic measurement, to estimate intravascular volume.

Objective: To determine if point of care ultrasound measurement of the caudal vena cava (CVC) diameter or the CVC diameter to the abdominal aorta (Ao) diameter (CVC:Ao) at the paralumbar view are associated with changes in intravascular volume, mean arterial pressure (MAP), or cardiac output in normovolemic and hypovolemic dogs.

Surgical interventions and outcome in a population of canine trauma patients.

Objective: To determine signalment, injury type, trauma severity score, and outcome of canine trauma patients undergoing surgical (emergency room [ER] or operating room [OR]) and nonsurgical treatment in addition to time to surgery, specialty services involved, and cost in the OR surgery population.

Design: Retrospective evaluation of medical record and hospital trauma registry data on canine trauma cases.

Setting: University teaching hospital.

A guide to photosynthetic gas exchange measurements: Fundamental principles, best practice and potential pitfalls.

Gas exchange measurements enable mechanistic insights into the processes that underpin carbon and water fluxes in plant leaves which in turn inform understanding of related processes at a range of scales from individual cells to entire ecosytems. Given the importance of photosynthesis for the global climate discussion it is important to (a) foster a basic understanding of the fundamental principles underpinning the experimental methods used by the broad community, and (b) ensure best practice and correct data interpretation within the research community. In this review, we outline the biochemical and biophysical parameters of photosynthesis that can be investigated with gas exchange measurements and we provide step-by-step guidance on how to reliably measure them.

Sidestream dark field imaging and biomarker evaluation reveal minimal significant changes to the microcirculation and glycocalyx in a canine hemorrhagic shock model.

Objective: To investigate the effects of hemorrhagic shock and fresh whole blood resuscitation on the microcirculation and endothelial glycocalyx using sidestream dark field (SDF) imaging and plasma biomarkers.

Animals: 8 purpose-bred dogs.

Methods: Pressure-targeted hemorrhagic shock was induced in anesthetized dogs.

Transgenic strategies to improve the thermotolerance of photosynthesis.

Warming driven by the accumulation of greenhouse gases in the atmosphere is irreversible over at least the next century, unless practical technologies are rapidly developed and deployed at scale to remove and sequester carbon dioxide from the atmosphere. Accepting this reality highlights the central importance for crop agriculture to develop adaptation strategies for a warmer future. While nearly all processes in plants are impacted by above optimum temperatures, the impact of heat stress on photosynthetic processes stand out for their centrality.

Surgical interventions and outcome in a population of feline trauma patients.

Objective: To determine signalment, injury type, trauma severity score, and outcome of feline trauma patients undergoing surgical (emergency room [ER] and operating room [OR]) and nonsurgical treatments in addition to time to surgery, specialty services involved, and cost in the OR surgery population.

Design: Retrospective evaluation of medical record and hospital trauma registry data on feline trauma cases.

Setting: University teaching hospital.

Removal of redox-sensitive Rubisco Activase does not alter Rubisco regulation in soybean.

Rubisco activase (Rca) facilitates the catalytic repair of Rubisco, the CO-fixing enzyme of photosynthesis, following periods of darkness, low to high light transitions or stress. Removal of the redox-regulated isoform of Rubisco activase, Rca-α, enhances photosynthetic induction in Arabidopsis and has been suggested as a strategy for the improvement of crops, which may experience frequent light transitions in the field; however, this has never been tested in a crop species. Therefore, we used RNAi to reduce the Rca-α content of soybean (Glycine max cv.

Temperature-induced changes in Arabidopsis Rubisco activity and isoform expression.

In many plant species, expression of the nuclear encoded Rubisco small subunit (SSu) varies with environmental changes, but the functional role of any changes in expression remains unclear. In this study, we investigated the impact of differential expression of Rubisco SSu isoforms on carbon assimilation in Arabidopsis. Using plants grown at contrasting temperatures (10 °C and 30 °C), we confirm the previously reported temperature response of the four RbcS genes and extend this to protein expression, finding that warm-grown plants produce Rubisco containing ~65% SSu-B and cold-grown plants produce Rubisco with ~65% SSu-A as a proportion of the total pool of subunits.

Acidic chemical corneal ulceration secondary to nail polish spill in a puppy.

Purpose: To describe the treatment of an acidic chemical corneal ulceration in a puppy secondary to nail polish spilling on and adhering to the cornea.

Case Summary: A 12-week-old neutered male Australian Shepherd mix dog was presented to Colorado State University Veterinary Teaching Hospital's (CSU-VTH) Emergency and Urgent Care service acutely after exposure to nail polish spilling on the left eye (OS). Initial ophthalmic examination revealed nail polish adhered to approximately 80% of the cornea with moderate diffuse corneal edema and chemosis, and green nail polish adhered to the skin and fur of the periocular area.

Alternative pathway to photorespiration protects growth and productivity at elevated temperatures in a model crop.

Adapting crops to warmer growing season temperatures is a major challenge in mitigating the impacts of climate change on crop production. Warming temperatures drive greater evaporative demand and can directly interfere with both reproductive and vegetative physiological processes. Most of the world's crop species have C3 photosynthetic metabolism for which increasing temperature means higher rates of photorespiration, wherein the enzyme responsible for fixing CO fixes O instead followed by an energetically costly recycling pathway that spans several cell compartments.

Genome-wide analysis and transcriptional regulation of the typical and atypical thioredoxins in Arabidopsis thaliana.

Thioredoxins (TRXs), a large subclass of ubiquitous oxidoreductases, are involved in thiol redox regulation. Here, we performed a comprehensive analysis of TRXs in the Arabidopsis thaliana genome, revealing 41 genes encoding 18 typical and 23 atypical TRXs, and 6 genes encoding thioredoxin reductases (TRs). The high number of atypical TRXs indicates special functions in plants that mostly await elucidation.

The effect of increasing temperature on crop photosynthesis: from enzymes to ecosystems.

As global land surface temperature continues to rise and heatwave events increase in frequency, duration, and/or intensity, our key food and fuel cropping systems will likely face increased heat-related stress. A large volume of literature exists on exploring measured and modelled impacts of rising temperature on crop photosynthesis, from enzymatic responses within the leaf up to larger ecosystem-scale responses that reflect seasonal and interannual crop responses to heat. This review discusses (i) how crop photosynthesis changes with temperature at the enzymatic scale within the leaf; (ii) how stomata and plant transport systems are affected by temperature; (iii) what features make a plant susceptible or tolerant to elevated temperature and heat stress; and (iv) how these temperature and heat effects compound at the ecosystem scale to affect crop yields.

Big progress for small subunits: new Rubisco mutants in Arabidopsis.

This article comments on: . 2020. Generating and characterizing single- and multigene mutants of the Rubisco small subunit family in Arabidopsis.

Ozone tolerant maize hybrids maintain Rubisco content and activity during long-term exposure in the field.

Ozone pollution is a damaging air pollutant that reduces maize yields equivalently to nutrient deficiency, heat, and aridity stress. Therefore, understanding the physiological and biochemical responses of maize to ozone pollution and identifying traits predictive of ozone tolerance is important. In this study, we examined the physiological, biochemical and yield responses of six maize hybrids to elevated ozone in the field using Free Air Ozone Enrichment.

In vivo evidence for a regulatory role of phosphorylation of Rubisco activase at the Thr78 site.

Rubisco activase (Rca) is phosphorylated at threonine-78 (Thr78) in low light and in the dark, suggesting a potential regulatory role in photosynthesis, but this has not been directly tested. To do so, we transformed an -knockdown mutant largely lacking redox regulation with wild-type Rca-β or Rca-β with Thr78-to-Ala (T78A) or Thr78-to-Ser (T78S) site-directed mutations. Interestingly, the T78S mutant was hyperphosphorylated at the Ser78 site relative to Thr78 of the Rca-β wild-type control, as evidenced by immunoblotting with custom antibodies and quantitative mass spectrometry.

Successful management of acute bilirubin encephalopathy in a dog with immune-mediated hemolytic anemia using therapeutic plasma exchange.

Objective: To describe the successful management of acute bilirubin encephalopathy in a dog with immune-mediated hemolytic anemia (IMHA) treated with therapeutic plasma exchange (TPE) in conjunction with conventional medical management.

Case Summary: A 6-year-old neutered male Australian Cattle Dog diagnosed with IMHA developed severe hyperbilirubinemia and stupor within the first 48 hours of implementing immunosuppressive therapy consisting of corticosteroids and mycophenolate. The patient received 4 blood transfusions during this period, but remained severely anemic PCV (18%) and experienced a subsequent increase in total bilirubin from 78 µmol/L (4.

Synthetic glycolate metabolism pathways stimulate crop growth and productivity in the field.

Photorespiration is required in C plants to metabolize toxic glycolate formed when ribulose-1,5-bisphosphate carboxylase-oxygenase oxygenates rather than carboxylates ribulose-1,5-bisphosphate. Depending on growing temperatures, photorespiration can reduce yields by 20 to 50% in C crops. Inspired by earlier work, we installed into tobacco chloroplasts synthetic glycolate metabolic pathways that are thought to be more efficient than the native pathway.

Temperature response of Rubisco kinetics in Arabidopsis thaliana: thermal breakpoints and implications for reaction mechanisms.

Enhancement of Rubisco kinetics could improve photosynthetic efficiency, ultimately resulting in increased crop yield. However, imprecise knowledge of the reaction mechanism and the individual rate constants limits our ability to optimize the enzyme. Membrane inlet mass spectrometry (MIMS) may offer benefits over traditional methods for determining individual rate constants of the Rubisco reaction mechanism, as it can directly monitor concentration changes in CO2, O2, and their isotopologs during assays.

Photosystem II Subunit S overexpression increases the efficiency of water use in a field-grown crop.

Insufficient water availability for crop production is a mounting barrier to achieving the 70% increase in food production that will be needed by 2050. One solution is to develop crops that require less water per unit mass of production. Water vapor transpires from leaves through stomata, which also facilitate the influx of CO during photosynthetic assimilation.