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Large amounts of nitrogen (N) fertiliser are often applied to commercial plantations in southern Australia to obtain high growth rates. The growth response to fertiliser can be realised through increased foliar N and hence improved leaf-level photosynthetic capacity, or through increased leaf area production, which in turn increases light capture and hence canopy-level photosynthesis. While extra leaf area is beneficial to a tree in this regard, extra leaves may also incur costs in terms of both carbon (C) and water. Since canopy water use scales with total leaf area, greater leaf area could cause stomatal closure in times of water shortage, reducing the C assimilation rate. Here, we used three factorial N × phosphorus fertiliser experiments in Eucalyptus nitens plantations across Tasmania, Australia, to assess the effects of 12 fertiliser treatments on C- and water-related gas exchange, foliar N and trunk shrinkage. As prior research in this system has demonstrated an increase in leaf area in response to high N, we investigated the potential physiological costs and benefits of this extra leaf area. N application appeared to have consequences for plant water use, as evidenced by greater trunk shrinkage and lower stomatal conductance. However, this varied by site and year, indicating that the response is dependent on environmental conditions. These results highlight the importance of considering site conditions when prescribing fertiliser application regimes because adding large amounts of N could have unintended consequences for growth due to increased leaf area and hence potential water use, especially in dry conditions. [ABSTRACT FROM AUTHOR]

Native perennial grass and sown grass-legume pastures are an important agricultural and environmental resource. We investigated the impact of rising carbon dioxide concentration ([CO2]) and projected climate changes on these pasture ecosystems in southeastern Tasmania, Australia, using a biophysical simulation model, EcoMod. The model consists of interdependent modules that describe soil physicochemical and hydrological characteristics, and pasture growth and senescence, with fluxes described by empirical and mechanistic equations. Our simulations showed that in native pastures, projected climate change increased the biomass of C4 grasses, with limited impact upon C3 grasses, a trend reversed by rising [CO2]. In sown pastures, projected climate change decreased the biomass of perennial rye grass Lolium perenne and total biomass markedly by 2070, whilst subterranean clover Trifolium snbterraneum biomass increased, Subterranean clover biomass changed little with increased [CO2] alone, whereas perennial rye grass biomass increased. Responses across pastures reflected species' tolerances to environmental factors, with projected climate change generally having more of an impact on biomass than rising [CO2]. Changes in both [CO2] and climate led to a reduction in protein content and digestibility. Soil inorganic nutrient concentrations decreased with increasing [CO2] and increased with projected climate change. Further simulations should investigate whether these patterns are robust for different sites and alternative environmental futures. Our results reinforce the need to pursue adaptation strategies in response to environmental change in order to maintain productive pasture ecosystems. [ABSTRACT FROM AUTHOR]

In order to ascertain whether the major species of continental Antarctic macrolichens are photosynthetically active during summer conditions, the chlorophyll fluorescence of three lichen species [Umbilicaria decussata (Vill.) Zahlbr., Pseudephebe minuscule (Nyl. Ex Arnold) Brodo and Hawksw, and Usnea sphacelata R. Br.] was monitored in the vicinity of Casey Station, Wilkers Land, continental Antarctica using a PAM-2000 modulated fluorescence system. Lichens were studied when in equilibrium with the atmosphere as well as when moistened by snow showere. Photochemical quantum yield was estimated as ΔF/F'm and related to thallus water content as well as microclimatic conditions. Lichens were photosynthetically active only when moistened by snow fall or by run-off from snow melt. The levels of photosynthetic activity in the field for all species were influenced by microenvironmental conditions and patterns in response were site and species specific. Highest levels of photosynthetic activity was reduced by cold as well as warm, bright conditions. Highest thallus water contents occurred during the middle of the day after substantial falls of snow. P. minuscule maintained highest thallus water contents at all sites and appears to have a high water compensation point which is related to its observed distribution patterns. Umbilicaria decussata studied in the laboratory did not become photosynthetically active even when exposed to 95% relative humidity (RH) for 51 h and, when dehydrating after artificial wetting, showed an optimum thallus water content for photosynthesis of ca 90% dry weight and a thallus water compensation point of about 35% dry weight. In the field U. decussata exposed to the atmosphere had low thallus water contents (ca 30%) which was not related to RH. The results indicate that the lichens are photosynthetically inactive for most of the summer period and are totally reliant on snow as a water supply . This is important when modeling carbon gain and growth rates of continental antarctic lichens. [ABSTRACT FROM AUTHOR]

Dissolved organic carbon (DOC) released by macroalgae supports coastal ocean carbon cycling and contributes to the total oceanic DOC pool. Salinity fluctuates substantially in coastal marine environments due to natural and anthropogenic factors, yet there is limited research on how salinity affects DOC release by ecologically important macroalgae. Here we determined the effect of short-term salinity changes on rates of DOC release by the habitat-forming fucalean seaweed Sargassum fallax (Ochrophyta). Lateral branches (~4 g) cut at the axes of mature individuals were incubated across a salinity gradient (4-46) for 24 h under a 12:12 light:dark cycle, and seawater was sampled for DOC at 0, 12, and 24 h. Physiological assays (tissue water content, net photosynthesis, respiration, tissue carbon, and nitrogen content) were undertaken at the end of the 24-h experiment. Dissolved organic carbon release increased with decreasing salinity while net photosynthesis decreased. Dissolved organic carbon release rates at the lowest salinity tested (4) were ~3.3 times greater in the light than in the dark, indicating two potential DOC release mechanisms: light-mediated active exudation and passive release linked to osmotic stress. Tissue water content decreased with increasing salinity. These results demonstrate that hyposalinity stress alters the osmotic status of S. fallax, reducing photosynthesis and increasing DOC release. This has important implications for understanding how salinity conditions encountered by macroalgae may affect their contribution to the coastal ocean carbon cycle., (© 2024 Phycological Society of America.)

Background: Rhino-orbital cerebral mucormycosis (ROCM) is a rare infection caused by an invasive fungus and found predominantly in immunocompromised patients. The presentation of ROCM ranges from a mild headache, fever, and sinusitis to vision loss, altered mental status, and facial disfigurement secondary to local tissue invasion. ROCM can cause significant morbidity and mortality and requires prompt diagnosis with timely evaluation by surgical and infectious disease specialists. Cases of ROCM have been reported extensively in internal medicine, infectious disease, and otolaryngology literature. However, there are very few reports in emergency medicine literature in the United States., Case Report: A 72-year-old woman presented to the Emergency Department (ED) with altered mental status, 4 days of left-sided facial numbness and weakness, and sudden facial pain, swelling, and erythema. Laboratory analysis was consistent with diabetic ketoacidosis. Noncontrast computed tomography of the head and magnetic resonance imaging of the brain demonstrated findings indicative of invasive fungal infection of the left sinus and orbit with extension to the cavernous sinus and surrounding cranial nerves. She was initiated on broad-spectrum antifungals, but based on the extent of the infection, was not a surgical candidate. She subsequently transitioned to a comfort-based plan of care and died 6 days after initial ED presentation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Early recognition and initiation of treatment can potentially mitigate the devastating outcomes of ROCM, therefore it is critical to be aware of this condition and have a high level of suspicion in susceptible patients., (Copyright © 2022 Elsevier Inc. All rights reserved.)

A growing body of work examines the direct and indirect effects of climate change on ecosystems, typically by using manipulative experiments at a single site or performing meta-analyses across many independent experiments. However, results from single-site studies tend to have limited generality. Although meta-analytic approaches can help overcome this by exploring trends across sites, the inherent limitations in combining disparate datasets from independent approaches remain a major challenge. In this paper, we present a globally distributed experimental network that can be used to disentangle the direct and indirect effects of climate change. We discuss how natural gradients, experimental approaches, and statistical techniques can be combined to best inform predictions about responses to climate change, and we present a globally distributed experiment that utilizes natural environmental gradients to better understand long-term community and ecosystem responses to environmental change. The warming and (species) removal in mountains (WaRM) network employs experimental warming and plant species removals at high- and low-elevation sites in a factorial design to examine the combined and relative effects of climatic warming and the loss of dominant species on community structure and ecosystem function, both above- and belowground. The experimental design of the network allows for increasingly common statistical approaches to further elucidate the direct and indirect effects of warming. We argue that combining ecological observations and experiments along gradients is a powerful approach to make stronger predictions of how ecosystems will function in a warming world as species are lost, or gained, in local communities., Competing Interests: The authors declare that they have no conflict of interest., (© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Plants are subject to trade-offs among growth strategies such that adaptations for optimal growth in one condition can preclude optimal growth in another. Thus, we predicted that a plant species that responds positively to one global change treatment would be less likely than average to respond positively to another treatment, particularly for pairs of treatments that favor distinct traits. We examined plant species' abundances in 39 global change experiments manipulating two or more of the following: CO 2 , nitrogen, phosphorus, water, temperature, or disturbance. Overall, the directional response of a species to one treatment was 13% more likely than expected to oppose its response to a another single-factor treatment. This tendency was detectable across the global data set, but held little predictive power for individual treatment combinations or within individual experiments. Although trade-offs in the ability to respond to different global change treatments exert discernible global effects, other forces obscure their influence in local communities., (© 2021 The Ecological Society of America.)

Carbon sequestration is defined as the secure storage of carbon-containing molecules for >100 years, and in the context of carbon dioxide removal for climate mitigation, the origin of this CO 2 is from the atmosphere. On land, trees globally sequester substantial amounts of carbon in woody biomass, and an analogous role for seaweeds in ocean carbon sequestration has been suggested. The purposeful expansion of natural seaweed beds and aquaculture systems, including into the open ocean (ocean afforestation), has been proposed as a method of increasing carbon sequestration and use in carbon trading and offset schemes. However, to verify whether CO 2 fixed by seaweeds through photosynthesis leads to carbon sequestration is extremely complex in the marine environment compared to terrestrial systems, because of the need to jointly consider: the comparatively rapid turnover of seaweed biomass, tracing the fate of carbon via particulate and dissolved organic carbon pathways in dynamic coastal waters, and the key role of atmosphere-ocean CO 2 exchange. We propose a Forensic Carbon Accounting approach, in which a thorough analysis of carbon flows between the atmosphere and ocean, and into and out of seaweeds would be undertaken, for assessing the magnitude of CO 2 removal and robust attribution of carbon sequestration to seaweeds., (© 2022 Phycological Society of America.)

Objective: To assess the efficacy and safety of a virtual reality distraction for needle pain in 2 common hospital settings: the emergency department (ED) and outpatient pathology (ie, outpatient laboratory). The control was standard of care (SOC) practice., Study Design: In 2 clinical trials, we randomized children aged 4-11 years undergoing venous needle procedures to virtual reality or SOC at 2 tertiary Australian hospitals. In the first study, we enrolled children in the ED requiring intravenous cannulation or venipuncture. In the second, we enrolled children in outpatient pathology requiring venipuncture. In the ED, 64 children were assigned to virtual reality and 59 to SOC. In pathology, 63 children were assigned to virtual reality and 68 to SOC; 2 children withdrew assent in the SOC arm, leaving 66. The primary endpoint was change from baseline pain between virtual reality and SOC on child-rated Faces Pain Scale-Revised., Results: In the ED, there was no change in pain from baseline with SOC, whereas virtual reality produced a significant reduction in pain (between-group difference, -1.78; 95% CI, -3.24 to -0.317; P = .018). In pathology, both groups experienced an increase in pain from baseline, but this was significantly less in the virtual reality group (between-group difference, -1.39; 95% CI, -2.68 to -0.11; P = .034). Across both studies, 10 participants experienced minor adverse events, equally distributed between virtual reality/SOC; none required pharmacotherapy., Conclusions: In children aged 4-11 years of age undergoing intravenous cannulation or venipuncture, virtual reality was efficacious in decreasing pain and was safe., Trial Registration: Australia and New Zealand Clinical Trial Registry: ACTRN12617000285358p., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Biofouling in canals and pipelines used for hydroelectric power generation decreases the flow capacity of conduits. A pipeline rig was designed consisting of test sections of varying substrata (PVC, painted steel) and light levels (transparent, frosted, opaque). Stalk-forming diatoms were abundant in both the frosted and transparent PVC pipes but negligible in the painted steel and opaque PVC pipes. Fungi were slightly more abundant in the painted steel pipe but equally present in all the other pipes while bacterial diversity was similar in all pipes. Photosynthetically functional biofouling (mainly diatoms) was able to develop in near darkness. Different biological fouling compositions generated differing friction factors. The highest friction factor was observed in the transparent pipe (densest diatom fouling), the lowest peak friction for the opaque PVC pipe (lowest fouling biomass), and with the painted steel pipe (high fouling biomass, but composed of fungal and bacterial crusts) being intermediate between the opaque and frosted PVC pipes.

Background: Multiple sclerosis (MS) is a debilitating disease that negatively impacts patients' lives., Objective: ENABLE assessed the effect of long-term prolonged-release (PR) fampridine (dalfampridine extended release in the United States) treatment on patient-perceived health impact in patients with MS with walking impairment., Methods: ENABLE was a 48-week, open-label, Phase 4 study of PR-fampridine 10 mg twice daily. Patients who showed any improvement in Timed 25-Foot Walk walking speed at weeks 2 and 4 and any improvement in 12-item MS Walking Scale score at week 4 remained on treatment. The primary endpoint was change from baseline in 36-Item Short-Form Health Survey (SF-36) physical component summary (PCS) score., Results: At week 4, 707/901 (78.5%) patients met the criteria to remain on treatment. Patients on treatment demonstrated significant and clinically meaningful improvements in SF-36 PCS scores from baseline (mean change (95% confidence interval)) to week 12 (4.30 (3.83, 4.78); p < 0.0001), week 24 (3.75 (3.23, 4.27); p < 0.0001), week 36 (3.46 (2.95, 3.97); p < 0.0001), and week 48 (3.24 (2.72, 3.77); p < 0.0001). Significant improvements from baseline were also demonstrated in secondary health measures in patients on treatment., Conclusion: PR-fampridine improved patient-perceived physical and psychological health impact of MS measured in a real-life setting., (© The Author(s), 2015.)

Background: Mobility impairment is a common disability in MS and negatively impacts patients' lives., Objective: Evaluate the effect of prolonged-release (PR) fampridine (extended-release dalfampridine in the United States) on self-assessed walking disability, dynamic/static balance and safety in patients with MS., Methods: MOBILE was a randomised, double-blind, exploratory, placebo-controlled trial. Patients with progressive/relapsing-remitting MS and Expanded Disability Status Scale score of 4.0-7.0 were treated with PR-fampridine or placebo twice daily for 24 weeks. Efficacy endpoints included change from baseline in the 12-item MS Walking Scale (MSWS-12), Timed Up and Go (TUG) test and Berg Balance Scale (BBS)., Results: 132 patients were randomised at 24 sites in six countries. PR-fampridine therapy resulted in greater median improvements from baseline in MSWS-12 score, TUG speed and BBS total score versus placebo over 24 weeks. A higher proportion of patients receiving PR-fampridine versus placebo experienced significant improvements at MSWS-12 improvement thresholds ⩾7 (p = 0.0275), ⩾8 (p = 0.0153) and ⩾9 points (p = 0.0088) and TUG speed thresholds ⩾10% (p = 0.0021) and ⩾15% (p = 0.0262). PR-fampridine was well tolerated., Conclusions: PR-fampridine therapy resulted in early and sustained improvements in broad measures of walking and balance over six months., (© The Author(s), 2015.)

Bacterial capsules are common targets for antibody-mediated immunity. The capsule of Bacillus anthracis is unusual among capsules because it is composed of a polymer of poly-γ-d-glutamic acid (γdPGA). We previously generated murine IgG3 monoclonal antibodies (mAbs) to γdPGA that were protective in a murine model of pulmonary anthrax. IgG3 antibodies are characteristic of the murine response to polysaccharide antigens. The goal of the present study was to produce subclass switch variants of the γdPGA mAbs (IgG3 → IgG1 → IgG2b → IgG2a) and assess the contribution of subclass to antibody affinity and protection. Subclass switch antibodies had identical variable regions but differed in their heavy chains. The results showed that a switch from the protective IgG3 to IgG1, IgG2b or IgG2a was accompanied by i) a loss of protective activity ii) a change in mAb binding to the capsular matrix, and iii) a loss of affinity. These results identify a role for the heavy chain constant region in mAb binding. Hybrid mAbs were constructed in which the CH1, CH2 or CH3 heavy chain constant domains from a non-protective, low binding IgG2b mAb were swapped into the protective IgG3 mAb. The IgG3 mAb that contained the CH1 domain from IgG2b showed no loss of affinity or protection. In contrast, swapping the CH2 or CH3 domains from IgG2b into IgG3 produced a reduction in affinity and a loss of protection. These studies identify a role for the constant region of IgG heavy chains in affinity and protection against an encapsulated bacterial pathogen.

During the middle of the 1992 austral winter in the northern Windmill Islands, continental Antarctica, a highly unusual climatic event occurred in which the air temperature exceeded 0°C for some 60 h, at the end of which there was a significant rain shower before the ambient temperature returned to subzero conditions. This event caused most of the snow cover to melt and refreeze as clear ice. Lichens were thus rehydrated in the dark, in some places completely inundated, then frozen in ice. The effect that these conditions had on the distribution of K, Na, Mg and Ca within the thallus was estimated for two of the dominant macrolichen species, Umbilicaria decussata (Vill.) Zahlbr. and Usnea sphacelata R.Br, from three sites on a knoll on Clark Peninsula. One site acted as a natural control, owing to the very deep snow cover at the site, which protected lichens from the rewetting event. Despite persistent differences between species and the various sites, there was no overall effect of the climatic event on the membrane integrity of either lichen species. Only Usnea sphacelata from the most exposed site showed a significant leakage of K across the cell membrane, which indicated a loss of membrane integrity. Overall, both species were tolerant of the extreme conditions, although Umbilicaria decussata was the more tolerant.