"Before I came to the hospice, I had nobody". A qualitative exploration of what patients, family-caregivers, clinicians and volunteers valued most about home, day therapy or inpatient hospice services.

Background: Globally, the demand for hospice care continues to grow resulting in substantial resource burden. Whilst some countries are able to rely on fixed government contributions, statutory funding for palliative care in the United Kingdom is unequally distributed. These unstable funding streams and increased demand means that hospices need to evidence their value. Objective: This study explored the experiences of patients and family-caregivers to determine what they valued most from accessing hospice services in Wales. Methods: In this large multi-site qualitative study, 94 semi-structured interviews and 2 focus groups were conducted with hospice patients (n = 45), family-caregivers (n = 18), hospice staff (n = 31) and volunteers (n = 10). The audio recordings were transcribed verbatim and analysed using Framework analysis. Results: Seven themes described patient and family-caregiver experiences and what they valued most: relationships with staff and volunteers, greater support networks which reduced social isolation and loneliness, provision of information and advice which improved patient autonomy, symptom management and subsequent reduction in psychological distress, improvements in patient functionality, mobility and overall physical health and respite relief which promoted improved relationships. Conclusion: This is the largest study to explore what patients and family-caregivers value from hospice care. Findings indicate that hospice care provides a truly needs-led and strengths-based service to those who are nearing and at the end-of-life, which is highly valued by patients and family members.

An integrated public health response to an outbreak of Murray Valley encephalitis virus infection during the 2022-2023 mosquito season in Victoria.

Introduction: Murray Valley encephalitis virus (MVEV) is a mosquito-borne flavivirus known to cause infrequent yet substantial human outbreaks around the Murray Valley region of south-eastern Australia, resulting in significant mortality. Methods: The public health response to MVEV in Victoria in 2022-2023 included a climate informed pre-season risk assessment, and vector surveillance with mosquito trapping and laboratory testing for MVEV. Human cases were investigated to collect enhanced surveillance data, and human clinical samples were subject to serological and molecular testing algorithms to assess for co-circulating flaviviruses. Equine surveillance was carried out via enhanced investigation of cases of encephalitic illness. Integrated mosquito management and active health promotion were implemented throughout the season and in response to surveillance signals. Findings: Mosquito surveillance included a total of 3,186 individual trapping events between 1 July 2022 and 20 June 2023. MVEV was detected in mosquitoes on 48 occasions. From 2 January 2023 to 23 April 2023, 580 samples (sera and CSF) were tested for flaviviruses. Human surveillance detected 6 confirmed cases of MVEV infection and 2 cases of "flavivirus-unspecified." From 1 September 2022 to 30 May 2023, 88 horses with clinical signs consistent with flavivirus infection were tested, finding one probable and no confirmed cases of MVE. Discussion: The expanded, climate-informed vector surveillance system in Victoria detected MVEV in mosquitoes in advance of human cases, acting as an effective early warning system. This informed a one-health oriented public health response including enhanced human, vector and animal surveillance, integrated mosquito management, and health promotion.

Lessons from the re-emergence of imported measles cases following the COVID-19 pandemic in Victoria, Australia.

Introduction: Australia was declared to have eliminated endemic measles in 2014; however, imported cases continue to pose a threat of outbreaks. International travel restrictions during the coronavirus disease 2019 (COVID-19) pandemic led to a rapid decline in measles cases. The re-opening of the Australian international border to measles endemic regions returns the threat of outbreaks, which may be further compounded by disruptions in routine vaccinations during the COVID-19 pandemic. We consider lessons learned from the public health response to recent measles cases. Methods: This case series includes all confirmed measles cases meeting the national case definition reported to the Victorian Government Department of Health (the Department) between 1 January and 31 December 2022. The Department conducted active case finding and contact tracing of all cases in line with national guidelines. Cases were descriptively analysed. Results: In 2022, six of the seven measles cases reported in Australia occurred in Victoria, all of whom resided in Australia and acquired their infection overseas. Three cases were unlinked, and three formed an epidemiologically-linked household cluster. One case was partially vaccinated, one was not eligible for vaccination, one had unknown vaccination status, and three were unvaccinated, one of whom was under 12 months old but would have been eligible for vaccination prior to travel to endemic regions. None of the cases led to secondary transmission within Australia. Discussion: Following the COVID-19 pandemic, measles importations have re-commenced in Victoria. Although few measles cases occurred in 2022 and none resulted in onwards transmission, imported measles cases remain complex and require substantial public health follow-up. Delays in case diagnosis and flight contact tracing pose a significant risk for outbreaks of measles. Public health interventions are needed to maintain high vaccination rates, improve contact tracing, and ensure public health authorities and healthcare providers can rapidly identify and respond to imported measles cases.

The impact of the 21 November 2016 epidemic thunderstorm asthma event on general practice clinics in metropolitan Melbourne, Australia.

BACKGROUND AND OBJECTIVES: On 21 November 2016, parts of Victoria experienced a devastating epidemic thunderstorm asthma (ETSA) event. The aim of this study was to describe the epidemiology and burden of the 2016 ETSA event at MedicineInsight-registered general practices in the Melbourne metropolitan area in Victoria, Australia. METHOD: A cross-sectional study was conducted using patient record data from 21-23 November 2016. Codes were developed to identify all patients presenting to MedicineInsight-registered general practices with asthma during the 2016 ETSA event. RESULTS: During the event, there were 787 more asthma-related encounters to MedicineInsight general practices than expected, which represented a 7.1-fold increase (605% increase). Estimates suggest that there were between approximately 8940 and 13,689 more asthma-related encounters than expected across metropolitan Melbourne. DISCUSSION: General practices were significantly affected by the 2016 ETSA event. This work highlights the important part that general practices play in responding to ETSA events and the need for these practices to be prepared to respond.

Evaluating factors affecting length of hospital stay in patients with metastatic bone tumors.

BACKGROUND: Specific medical conditions known to increase LOS following orthopedic surgery including congestive heart failure, diabetes mellitus and COPD. It is also known that patient demographics such as increasing age and non-white race can negatively affect orthopedic surgical outcomes However, there is a lack of research examining the effect of these variables on patients with metastatic bone disease regarding length of hospital stay and ultimately economic burden following surgery. The aim of this study is to identify factors affecting LOS in patients following surgery for bone metastasis. METHODS: A retrospective chart review was used to extract data from 93 patients with an underlying diagnosis of bony metastatic cancer who underwent an orthopedic surgical procedure. Data collected included: length of hospital stay, demographic information (age, sex, race, BMI, smoking status), complications (infection, DVT, PE, fractures), pre-operative lab values (WBC, Albumin, Creatinine, HbA1c), primary cancer type, and surgical procedure measures to understand which factors affected LOS. RESULTS: Increased LOS in this specific patient population was found to be associated with pre-existing diabetes (P = 0.005), obesity (P = 0.025), multiple disease sites (P = 0.042), or disease at the femur (P = 0.035). Patients had a decreased LOS when undergoing a prophylactic procedure (3.53 days vs 5.51 days for non-prophylactic procedure). DISCUSSION: These findings allow providers to better communicate expectations regarding the duration of admission and allows for a better estimation of cost burden for patients and health systems. The present study demonstrates increased LOS in patients undergoing orthopedic procedures for metastatic bone disease who had pre-existing diabetes, obesity, multiple disease sites, disease in the femur, or surgery for a pathologic fracture (as opposed to a prophylactic procedure). Understanding the factors affecting LOS in this patient population can optimize preoperative care, improve communication between the patient and provider, and ultimately decrease financial burden.

A comparison of depth of necrosis among adjuvant therapies used for the treatment of benign bone tumors.

BACKGROUND AND OBJECTIVES: Benign bone tumors are often treated with extended curettage utilizing an adjuvant therapy to eliminate any remaining tumor cells. The purpose of this study was to explore and compare the histologic depth of necrosis created by various adjuvant therapies used in the treatment of benign bone tumors. METHODS: A high-speed burr was utilized to create cortical defects within porcine humeri and femora. Phenol, polymethyl methacrylate (PMMA), argon beam coagulation (ABC), liquid nitrogen, and the Bipolar Hemostatic Sealer (BHS) were each applied to five defects, with an additional five defects left untreated as a control. The maximal depth of necrosis was determined under microscopic examination. RESULTS: The phenol, PMMA, ABC, liquid nitrogen, and BHS demonstrated an average histologic depth of necrosis of 0.30, 0.78, 2.54, 2.54, and 0.92 mm, respectively, each of which was significantly increased compared to the control group (p = .001, .003, .003, .01, and  <.001). Their respective variances, a measure of reproducibility, were 0.01, 0.09, 0.96, 1.93, and 0.03 mm2 . CONCLUSION: This study confirms, through histologic analysis, adjuvant therapies create a rim of cellular necrosis beyond that of burring during extended curettage, supporting their use in the treatment of benign bone tumors. Furthermore, it provides a head-to-head comparison.

The same anthocyanins served four different ways: Insights into anthocyanin structure-function relationships from the wintergreen orchid, Tipularia discolor.

Over 500 unique anthocyanins have been described to date, which vary in color, antioxidant, light-attenuating, and antimicrobial properties. Identification of anthocyanin chemical structure may therefore serve as an important clue to their in situ function in plants. We characterized the histological and chemical structures of anthocyanins associated with diverse leaf color patterns in the terrestrial orchid, Tipularia discolor, as a step towards understanding their ultimate function. Tipularia discolor produces a single wintergreen leaf in autumn, which is drab brown in color during expansion. Upper (adaxial) surfaces of fully-expanded leaves may be green, purple-spotted, or solid purple, while lower (abaxial) surfaces are bright magenta. Our results showed that the same three cyanidin 3,7,3'-triglucosides, in similar concentrations and proportions, accounted for coloration in each of these cases, and that different colors result from differences in histological location of anthocyanins (i.e. abaxial/adaxial epidermis, mesophyll). Anthocyanins with 3,7,3' linkage positions are rare in plants, occurring only within the orchid subfamily Epidendroideae, to which Tipularia belongs. These results are important to the discussion of anthocyanin structure-function because they serve as a reminder that 1) plants may employ the same anthocyanins in different anatomical locations to achieve a broad range of colors (and potentially adaptive functions), and 2) anthocyanin chemical structure and anatomical location are influenced by phylogenetic inertia, as well as natural selection.

Are convergence lines associated with high asthma presentation days? A case-control study in Melbourne, Australia.

BACKGROUND: In epidemic thunderstorm asthma (ETSA) events a large number of people develop asthma symptoms over a short period of time. This is thought to occur because of a unique combination of high amounts of pollen and certain meteorological conditions. However, the exact cause and mechanism of epidemic thunderstorm asthma remains unclear. OBJECTIVES: The objective of this study was to test the hypothesis that convergence lines may be a causative factor in ETSA events, by investigating whether convergence line weather events are associated with the occurrence of high asthma presentations days during the Victorian grass pollen season (October-December). METHODS: A case control method was used. All public hospitals within 75 km of the Melbourne weather radar were included, and data were taken from 2009 to 2017 during the Victorian grass pollen season. Cases hospital days were hospitals with a high number of asthma presentations within a 24-h period, and controls were hospitals with an expected number of asthma presentations. Exposure was defined as geographical proximity of a convergence line to the hospital case or control. RESULTS: Eighty-one case hospital days and 157 hospital day controls were included in the study. The odds of exposure to a convergence line were significantly higher for cases than for controls at all exposure distances. At 4 km, 80 of the 81 cases had been exposed to a convergence line. CONCLUSION: Convergence lines appear to be a necessary, but not sufficient, element in the cause of epidemic thunderstorm asthma. This is the first study to show a clear link between epidemic thunderstorm asthma and convergence lines.

Are Anterior Communicating Aneurysms Truly Anterior Communicating Aneurysms? An Observational Study.

OBJECTIVE: The term anterior communicating (ACom) aneurysm is often broadly used to classify any aneurysm formed on the A1-A2 junction, A1, A2, or ACom arteries. Aneurysm location has been associated with rupture risk, so whether an aneurysm is truly formed on the ACom artery can critically affect treatment decisions. The aim of this study was to reclassify broadly termed ACom aneurysms into 4 subgroups (A1, A2, true ACom, and A1-A2 junction) based on their location. METHODS: A retrospective, pilot study was conducted to identify all consecutive patients with ACom aneurysm managed over the past 4 years in a single center. Using computed tomography angiography, aneurysms were classified into 1 of the 4 subgroups. Additional information was collected on patient demographics, subarachnoid hemorrhages, projections of aneurysm dome, and aneurysm diameter. RESULTS: A total of 48 aneurysms with available computed tomography angiography imaging were included in the final analysis. The reclassification of ACom aneurysms into subgroups resulted in 40 A1-A2 junction, 6 true ACom, 2 A2, and zero A1 aneurysms. A total of 100% versus 80% of true ACom and A1-A2 junction aneurysms ruptured, respectively. All elective coiling procedures were performed on unruptured A1-A2 junction aneurysms. CONCLUSIONS: We found only 13% of the aneurysms initially referred to as ACom to be true ACom aneurysms. A more nuanced approach to ACom aneurysm classification may better guide management strategies.

What do patients and family-caregivers value from hospice care? A systematic mixed studies review.

BACKGROUND: It is not known which attributes of care are valued the most by those who experience hospice services. Such knowledge is integral to service development as it facilitates opportunities for continuous improvement of hospice care provision. The objectives of this mixed-studies systematic review were to explore patients' and their family carer views and experiences, to determine what they valued about adult hospice care in the UK. METHODS: ASSIA, PubMed, CINAHL and PsycINFO were searched from inception, up until March 2017 to identify qualitative, quantitative, and mixed-methods studies. Four additional searching techniques supplemented the main search and grey literature was included. A three-stage mixed-method systematic review was conducted with a sequential exploratory design. Thematic synthesis was used with qualitative data, followed by a narrative summary of the quantitative data. The qualitative and quantitative syntheses were then juxtaposed within a matrix to produce an overarching synthesis. RESULTS: Thirty-four studies highlighted that what patients and carers valued was generally context specific and stemmed from an amalgamation of hospice service components, which both individually and collectively contributed to improvements in quality of life. When the syntheses of qualitative and quantitative studies were viewed in isolation, the value placed on services remained relatively consistent, with some discrepancies evident in service availability. These were commonly associated with geographical variations, as well as differences in service models and timeframes. Through an overarching synthesis of the qualitative and quantitative evidence, however, notable variations and a more nuanced account of what people valued and why were more prominent, specifically in relation to a lack of social support for carers, disparate access to essential services, the underrepresentation of patients with a non-cancer diagnosis, and the dissatisfaction with the range of services provided. CONCLUSION: Review findings strengthen the existing evidence base and illuminates the underpinning elements of hospice care most valued by patients and their families. With large disparities in the availability of services, however, the underrepresentation of patients with non-malignant diseases and the limited evidence base demonstrating the adequate addressment of the social needs of carers, there continues to be considerable gaps that warrants further research.

Student performance on the Test of Scientific Literacy Skills (TOSLS) does not change with assignment of a low-stakes grade.

OBJECTIVE: Response-validated multiple-choice assessments are used in college courses to assess student learning gains. The ability of a test to accurately reflect student learning gains is highly dependent on the students' effort. Within our institution, lackluster student effort is common on response-validated multiple-choice concept assessments that are not included as a portion of the semester grade but are used to inform curricular changes. Thus, we set out to determine whether increasing testing stakes by assigning a grade on student performance had an effect on student score and self-reported effort. The Test of Scientific Literacy Skills (TOSLS) is a response-validated multiple-choice assessment used to measure scientific literacy in undergraduates. We administered the TOSLS to students enrolled in a general education Biology course, both during the first 2 weeks (pretest) and the last 2 weeks (posttest) of the course. RESULTS: Self-reported effort and TOSLS performance were significantly correlated in the ungraded cohort. This relationship did not exist in the graded sections. Our data indicate that assigning a low-stakes grade has no significant effect on mean student performance or self-reported effort on the TOSLS within our general education course.

Access to dental services for children with intellectual and developmental disabilities - A scoping review.

BACKGROUND: Children with Intellectual and Developmental Disabilities (IDD) face considerable challenges in participating in dental services. These challenges include resource constraints and inadequate skills of health service providers to work with this population. AIM: The aim was to scope published studies that addressed access to dental services for children with IDD in order to determine the extent to which various barriers have been researched, using an access framework derived from the literature. Access was defined to include the six dimensions of accessibility, availability, affordability, accommodation, acceptability, and appropriateness. METHOD: Arksey and O'Malley's scoping review framework was used. Relevant databases (e.g., Medline) were searched for all empirical studies conducted from January 2000 to February 2017 that met inclusion criteria. Data were extracted along the six dimensions of the access framework. RESULTS: Sixteen international studies were identified which indicated common key barriers to dental service use: the difficulties of physical inaccessibility, lack of access to information among carers, lack of knowledge of disability issues, and low experience and skills in caring for children with IDD among dental practitioners. CONCLUSIONS: Key recommendations made were exploring dental practitioners' understanding of disability legislation and developing training for practitioners to expand on issues specific to IDD.

Clouds homogenize shoot temperatures, transpiration, and photosynthesis within crowns of Abies fraseri (Pursh.) Poiret.

Multiple studies have examined the effects of clouds on shoot and canopy-level microclimate and physiological processes; none have yet done so on the scale of individual plant crowns. We compared incident photosynthetically active radiation (PAR), leaf temperatures, chlorophyll fluorescence, and photosynthetic gas exchange of shoots in three different spatial locations of Abies fraseri crowns on sunny (clear to partly cloudy) versus overcast days. The field site was a Fraser fir farm (1038 m elevation) in the Appalachian mountains, USA. Ten saplings of the same age class were marked and revisited for all measurements. Sunny conditions corresponded with 5-10× greater sunlight incidence on south-facing outer shoots compared to south-facing inner and north-facing outer shoots, which were shaded and received only indirect (diffuse) sunlight. Differences in spatial distribution of irradiance were mirrored in differences in shoot temperatures, photosynthesis, and transpiration, which were all greater in south-facing outer shoots compared to more shaded crown locations. In contrast, overcast conditions corresponded with more homogeneous sunlight distribution between north and south-facing outer shoots, and similar shoot temperatures, chlorophyll fluorescence (ΦPSII), photosynthesis, and transpiration; these effects were observed in south-facing inner shoots as well, but to a lesser extent. There was no significant difference in conductance between different crown locations on sunny or overcast days, indicating spatial differences in transpiration under sunny conditions were likely driven by leaf temperature differences. We conclude that clouds can affect spatial distribution of sunlight and associated physiological parameters not only within forest communities, but within individual crowns as well.

The success of the Uttarakhand Cluster: a case study of organisational change towards disability inclusive development.

BACKGROUND: Persons with disability are often marginalised and excluded from international development efforts. This case study reviews the success of Uttarakhand Cluster of development NGOs in changing organisational behaviour towards being disability inclusive in their development (DID) activities. METHODS: A triangulation of qualitative research methods was used, including key informant interviews, focus group discussions and review of textual data. RESULTS: The results synthesise data into Kotter's framework for organisational change, explaining the different stages of change experienced by the Cluster as it moved towards DID. Development of a disability mission, sharing of capacity and resources, and presence of disability champions were key in the organisations' transition towards DID. CONCLUSION: This case study demonstrates that the Cluster, a low - cost network, was able to drive organisational change and promote DID.

Perceptions and impact of plain packaging of tobacco products in low and middle income countries, middle to upper income countries and low-income settings in high-income countries: a systematic review of the literature.

OBJECTIVE: To review the current literature around the potential impact, effectiveness and perceptions of plain packaging in low income settings. METHOD: A systematic review of the literature. DATA SOURCES: 9 databases (PubMed, Global Health, Social Policy and Practice, Applied Social Sciences Index and Abstracts (ASSIA), CINAHL, PsycINFO, British Library for Development Studies (BLDS), Global Health Library and Scopus) were searched. The terms used for searching combined terms for smoking and tobacco use with terms for plain packaging. STUDY SELECTION: Studies investigating the impact of plain packaging on the determinants of tobacco use, such as smoking behaviour, appeal, prominence, effectiveness of health warnings, response to plain packs, attitudes towards quitting or likelihood of smoking in low-income settings, were identified. Studies must have been published in English and be original research of any level of rigour. DATA EXTRACTION: Two independent reviewers assessed studies for inclusion and extracted data. DATA SYNTHESIS: The results were synthesised qualitatively, with themes grouped under four key headings: appeal and attractiveness; salience of health warnings and perceptions of harm; enjoyment and perceived taste ratings; and perceptions of the impact on tobacco usage behaviour. RESULTS: This review has identified four articles that met the inclusion criteria. Studies identified that tobacco products in plain packaging had less appeal than in branded packaging in low-income settings. CONCLUSIONS: This review indicates that plain packaging appears to be successful in reducing appeal of smoking and packets, and supports the call for plain packaging to be widely implemented in conjunction with other tobacco control policies. However, there are considerable gaps in the amount of research conducted outside high-income countries.

Importance of natural cloud regimes to ecophysiology in the alpine species, Caltha leptosepala and Arnica parryi, Snowy Range Mountains, southeast Wyoming, USA.

The south-central Rocky Mountains, USA, are characterised by a dry, continental mesoclimate with typical convective cloud formation during the afternoon. Little is known about the specific influence of such predictable cloud patterns on the microclimate and ecophysiology of associated species. During the summer of 2012, days with afternoon clouds were most common (50% of all days) compared with completely clear (24%) or cloudy days (6.5%). In two representative alpine species, Caltha leptosepala DC. and Arnica parryi A. Gray, fully overcast days reduced mean daily photosynthesis (A) by nearly 50% relative to fully clear days. Mean afternoon A was significantly lower on fully cloudy days relative to days with afternoon clouds only or no clouds in both species. Notably, A did not differ during afternoon cloud days relative to clear afternoons. Afternoon clouds significantly reduced transpiration (E) in C. leptosepala relative to clear days, and both species showed mean reductions in plant water stress (i.e. higher Ψ), though this difference was not significant. Water use efficiency (WUE) (A/E) decreased from morning to afternoon, especially on cloudy days, and the presence of clouds had a positive effect on the light reactions of photosynthesis based on fluorescence measurements (Fv'/Fm'), in both species. Cloudy days were characterised by higher Fv/Fm than afternoon clouds and clear days during both the morning and the afternoon (especially for A. parryi) and recovery to near pre-dawn values for cloudy and afternoon cloud day types, but not clear days. Overall, similar ecophysiological advantages of this typical afternoon cloud pattern was apparent in both species, although their spatial microsite differences related to winter snow accumulation may also play an important role.

Support for a photoprotective function of winter leaf reddening in nitrogen-deficient individuals of Lonicera japonica.

Plants growing in high-light environments during winter often exhibit leaf reddening due to synthesis of anthocyanin pigments, which are thought to alleviate photooxidative stress associated with low-temperature photoinhibition through light attenuation and/or antioxidant activity. Seasonal high-light stress can be further exacerbated by a limited photosynthetic capacity, such as nitrogen-deficiency. In the present study, we test the following hypotheses using three populations of the semi-evergreen vine Lonicera japonica: (1) nitrogen deficiency corresponds with reduced photosynthetic capacity; (2) individuals with reduced photosynthetic capacity synthesize anthocyanin pigments in leaves during winter; and (3) anthocyanin pigments help alleviate high-light stress by attenuating green light. All populations featured co-occurring winter-green and winter-red leafed individuals on fully-exposed (high-light), south-facing slopes in the Piedmont of North Carolina, USA. Consistent with our hypotheses, red leaves consistently exhibited significantly lower foliar nitrogen than green leaves, as well as lower total chlorophyll, quantum yield efficiency, carboxylation efficiency, and photosynthesis at saturating irradiance (Asat). Light-response curves measured using ambient sunlight versus red-blue LED (i.e., lacking green wavelengths) demonstrated significantly reduced quantum yield efficiency and a higher light compensation point under sunlight relative to red-blue LED in red leaves, but not in green leaves, consistent with a (green) light-attenuating function of anthocyanin pigments. These results are consistent with the hypothesis that intraspecific anthocyanin synthesis corresponds with nitrogen deficiency and reduced photosynthetic capacity within populations, and support a light-attenuating function of anthocyanin pigments.

Photosynthetic costs and benefits of abaxial versus adaxial anthocyanins in Colocasia esculenta 'Mojito'.

MAIN CONCLUSION: Anthocyanins in upper (adaxial) leaf tissues provide greater photoprotection than in lower (abaxial) tissues, but also predispose tissues to increased shade acclimation and, consequently, reduced photosynthetic capacity. Abaxial anthocyanins may be a compromise between these costs/benefits. Plants adapted to shaded understory environments often exhibit red/purple anthocyanin pigmentation in lower (abaxial) leaf surfaces, but rarely in upper (adaxial) surfaces. The functional significance of this color pattern in leaves is poorly understood. Here, we test the hypothesis that abaxial anthocyanins protect leaves of understory plants from photo-oxidative stress via light attenuation during periodic exposure to high incident sunlight in the forest understory, without interfering with sunlight capture and photosynthesis during shade conditions. We utilize a cultivar of Colocasia esculenta exhibiting adaxial and abaxial anthocyanin variegation within individual leaves to compare tissues with the following color patterns: green adaxial, green abaxial (GG), green adaxial, red abaxial (GR), red adaxial, green abaxial (RG), and red adaxial, red abaxial (RR). Consistent with a photoprotective function of anthocyanins, tissues exhibited symptoms of increasing photoinhibition in the order (from least to greatest): RR, RG, GR, GG. Anthocyanic tissues also showed symptoms of shade acclimation (higher total chl, lower chl a/b) in the same relative order. Inconsistent with our hypothesis, we did not observe any differences in photosynthetic CO2 uptake under shade conditions between the tissue types. However, GG and GR had significantly (39 %) higher photosynthesis at saturating irradiance (A sat) than RG and RR. Because tissue types did not differ in nitrogen content, these patterns likely reflect differences in resource allocation at the tissue level, with greater nitrogen allocated toward energy processing in GG and GR, and energy capture in RG and RR (consistent with relative sun/shade acclimation). We conclude that abaxial anthocyanins are likely advantageous in understory environments because they provide some photoprotection during high-light exposure, but without the cost of decreased A sat associated with adaxial anthocyanin-induced shade syndrome.

Cloud immersion: an important water source for spruce and fir saplings in the southern Appalachian Mountains.

Cloud immersion can provide a potentially important moisture subsidy to plants in areas of frequent fog including the threatened spruce-fir communities of the southern Appalachian Mountains (USA). These mountaintop communities grow only above ~1,500 m elevation, harbor the endemic Abies fraseri, and have been proposed to exist because of frequent cloud immersion. While several studies have demonstrated the importance of cloud immersion to plant water balance, no study has evaluated the proportion of plant water derived from cloud moisture in this ecosystem. Using the isotopic mixing model, IsoSource, we analyzed the isotopic composition of hydrogen and oxygen for water extracted from ground water, deep soil, shallow soil, fog, and plant xylem at the upper and lower elevational limits both in May (beginning of the growing season) and October (end of the growing season). Cloud-immersion water contributed up to 31% of plant water at the upper elevation sites in May. High-elevation plants of both species also experienced greater cloud immersion and had greater cloud water absorption (14-31%) compared to low-elevation plants (4-17%). Greater cloud water uptake occurred in May compared to October, despite similar rainfall and cloud-immersion frequencies. These results demonstrate the important water subsidy that cloud-immersion water can provide. With a warming climate leading potentially to increases in the ceiling of the cloud base and, thus, less frequent cloud immersion, persistence of these relic mountaintop forests may depend on the magnitude of these changes and the compensating capabilities of other water sources.