45 research outputs found

    Increasing Food Production in Drylands Using Agrivoltaics

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    In the desert, native plants respond to the hottest part of the day by either closing their stomata, which would stop photosynthesis, or by simply reducing their photosynthesis rates due to heat stress. Soil water resources are also impacted due to significant evaporation. If plants have more shade during the day, will they photosynthesize more in the afternoon than plants without shade? Will these plants with shade transpire less, and thus need to be watered less? This study takes a look at plants which have grown under a photovoltaics array (a new agriculture practice called agrivoltaics) as well as plants which have grown in the open (modeling traditional agriculture practices). It was hypothesized the agrivoltaics practice will benefit plants by providing them shade and retaining soil moisture during the day as well as benefiting the photovoltaics by keeping them cooler to increase their efficiency. This study was designed to determine whether growing under the photovoltaic panels is beneficial, by collecting and analyzing data on photosynthesis (carbon uptake) and transpiration (water loss) rates of 8+ different species. These measurements will help answer which plants are best suited for being planted in an agrivoltaics installation

    A retrospective analysis of survival and prognostic factors after stereotactic radiosurgery for aggressive meningiomas

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    BACKGROUND: While most meningiomas are benign, aggressive meningiomas are associated with high levels of recurrence and mortality. A single institution’s Gamma Knife radiosurgical experience with atypical and malignant meningiomas is presented, stratified by the most recent WHO classification. METHODS: Thirty-one patients with atypical and 4 patients with malignant meningiomas treated with Gamma Knife radiosurgery between July 2000 and July 2011 were retrospectively reviewed. All patients underwent prior surgical resection. Overall survival was the primary endpoint and rate of disease recurrence in the brain was a secondary endpoint. Patients who had previous radiotherapy or prior surgical resection were included. Kaplan-Meier and Cox proportional hazards models were used to estimate survival and identify factors predictive of recurrence and survival. RESULTS: Post-Gamma Knife recurrence was identified in 11 patients (31.4%) with a median overall survival of 36 months and progression-free survival of 25.8 months. Nine patients (25.7%) had died. Three-year overall survival (OS) and progression-free survival (PFS) rates were 78.0% and 65.0%, respectively. WHO grade II 3-year OS and PFS were 83.4% and 70.1%, while WHO grade III 3-year OS and PFS were 33.3% and 0%. Recurrence rate was significantly higher in patients with a prior history of benign meningioma, nuclear atypia, high mitotic rate, spontaneous necrosis, and WHO grade III diagnosis on univariate analysis; only WHO grade III diagnosis was significant on multivariate analysis. Overall survival was adversely affected in patients with WHO grade III diagnosis, prior history of benign meningioma, prior fractionated radiotherapy, larger tumor volume, and higher isocenter number on univariate analysis; WHO grade III diagnosis and larger treated tumor volume were significant on multivariate analysis. CONCLUSION: Atypical and anaplastic meningiomas remain difficult tumors to treat. WHO grade III diagnosis and treated tumor volume were significantly predictive of recurrence and survival on multivariate analysis in aggressive meningioma patients treated with radiosurgery. Larger tumor size predicts poor survival, while nuclear atypia, necrosis, and increased mitotic rate are risk factors for recurrence. Clinical and pathologic predictors may help identify patients that are at higher risk for recurrence

    Development of a ParticipACTION App–Based Intervention for Improving Postsecondary Students’ 24-Hour Movement Guideline Behaviors: Protocol for the Application of Intervention Mapping

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    Background:The Canadian 24-Hour Movement Guidelines for adults provide specific recommendations for levels of physical activity, sedentary behavior, and sleep (ie, the movement behaviors) required for optimal health. Performance of the movement behaviors is associated with improved mental well-being. However, most postsecondary students do not meet the movement behavior recommendations within the Canadian 24-Hour Movement Guidelines and experience increased stress and declining well-being, suggesting the need for an intervention targeting students’ movement behaviors.Objective:We aimed to develop and implement a theory-informed intervention intended to improve the movement behaviors and mental well-being of first-year postsecondary students.Methods:The Intervention Mapping protocol was applied in the development and implementation of the intervention. Intervention Mapping entailed performing a needs assessment, determining the intervention outcomes, selecting theory- and evidence-based change methods and applications, preparing and producing intervention plans and materials, developing the implementation plan, and finally developing an evaluation plan. The Theoretical Domains Framework and the Behavior Change Wheel were also used in conjunction with the Intervention Mapping protocol to ensure a solid theoretical basis for the intervention. This protocol led to the development and implementation of a 6-week, theory-informed ParticipACTION app–based intervention aimed at helping first-year postsecondary students improve their movement behaviors and mental well-being. The developed app content provided students with information on each of the movement behaviors and behavioral strategies (ie, goal setting, action planning, monitoring, and coping planning). The use of Intervention Mapping allowed for the continuous involvement of various multidisciplinary partners and end users, ensuring that the intervention design and implementation was appropriate for the target audience. The feasibility, acceptability, and potential impact of the intervention will be examined in a subsequent proof-of-concept study at 2 Canadian university campuses.Results:Participant recruitment occurred during September 2021, and the intervention was conducted from October to December 2021. The deadline for completion of the postintervention questionnaire by participants was mid-December 2021. The analysis of data examining the feasibility, acceptability, and potential impact of the intervention began in January 2022, with the publication of the proof-of-concept evaluation expected in 2023.Conclusions:Intervention Mapping with the Theoretical Domains Framework and Behavior Change Wheel was a useful approach to combine evidence and theoretical concepts to guide the design and implementation of a ParticipACTION app–based intervention targeting postsecondary students’ movement behaviors and mental well-being. This process may serve as an example for other researchers developing multiple behavior change app–based interventions. Should the forthcoming evaluation demonstrate the intervention’s acceptability, feasibility, and potential impact, the intervention may provide a scalable method of improving postsecondary students’ movement behaviors and mental well-being

    Charting the Differences in Plant Growth Between Gardens in the Open and Under Solar Panels

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    Agrivoltaics is a relatively new arrangement of land use that collocates agriculture and solar photovoltaic panels. Within the context of several ongoing projects testing the practicality of agrivoltaics in the arid climate of southern Arizona, we used a portable photosynthesis analyzer to compare the rates of carbon uptake and water loss in Chiltepin, Jalapño, and Tomato plants grown under solar panels and in the open, as in traditional agriculture. The portable photosynthesis analyzer creates a microenvironment around the leaf that regulates temperature, carbon dioxide, humidity, and light to assess plant functions in ambient and artificial conditions. Two sets of measurements were taken, the first in dry conditions and the second in well-watered conditions. The goal is to gain insight into the tradeoffs of agrivoltaics in terms of photosynthesis and transpiration rates, water use efficiency, fruit production, and plant mass. The project has implications for food and energy production, especially on local scales and in arid regions

    Sadness and Anxiety Modify the Relationship Between COVID-19 and Gastrointestinal Symptoms at 6–12 Months of Follow-up

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    Background and Aims: It is unclear to what degree post-COVID-19 gastrointestinal (GI) symptoms are caused by the SARS-CoV-2 virus vs psychological factors related to the stress of the pandemic. To evaluate this, we compared rates of long-term GI and mental health symptoms in patients testing positive vs negative for SARS-CoV-2. Methods: Adults presenting for SARS-CoV-2 testing from April to November 2020 were prospectively enrolled in a longitudinal cohort. Six to 12 months later, the presence and severity of current GI and mental health symptoms were assessed on a 5-point Likert scale. A multivariable logistic regression model was used to estimate the odds of a positive COVID test for predicting GI symptoms, stratified by sadness/anxiety. Results: 749 COVID-positive and 107 COVID-negative patients completed the survey. The prevalence of at least one GI symptom was higher in patients with COVID-19 (29 vs 18%, P = .01). However, after stratifying by sadness/anxiety, differences in GI symptoms according to COVID status were no longer significant. On multivariable analysis, the adjusted odds ratio for GI symptoms was 8.26 (95% CI 4.04–16.9) for positive COVID with sadness/anxiety, 8.74 (95% CI 2.63–29.0) for negative COVID with sadness/anxiety, and 1.16 (95% CI 0.57–2.39) for positive COVID without sadness/anxiety, compared to a reference group of negative COVID without sadness/anxiety. Conclusion: After accounting for sadness and anxiety, there was no association between COVID-19 and the development of long-term GI symptoms. Post-COVID GI symptoms may be mediated bidirectionally through coexisting anxiety and depression, similar to disorders of gut-brain interaction

    Decreased Gut Microbiome Tryptophan Metabolism and Serotonergic Signaling in Patients With Persistent Mental Health and Gastrointestinal Symptoms After COVID-19.

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    INTRODUCTION: An estimated 15%-29% of patients report new gastrointestinal (GI) symptoms after coronavirus-19 disease (COVID-19) while 4%-31% report new depressive symptoms. These symptoms may be secondary to gut microbiome tryptophan metabolism and 5-hydroxytryptamine (5-HT)-based signaling. METHODS: This study used specimens from 2 patient cohorts: (i) fecal samples from patients with acute COVID-19 who participated in a randomized controlled trial testing prebiotic fiber and (ii) blood samples from patients with acute COVID-19. Six months after recovering from COVID-19, both cohorts answered questions related to GI symptoms and anxiety or depression. Microbiome composition and function, focusing on tryptophan metabolism-associated pathways, and plasma 5-HT were assessed. RESULTS: In the first cohort (n = 13), gut microbiome L-tryptophan biosynthesis during acute COVID-19 was decreased among those who developed more severe GI symptoms (2.0-fold lower log activity comparing those with the most severe GI symptoms vs those with no symptoms, P = 0.06). All tryptophan pathways showed decreased activity among those with more GI symptoms. The same pathways were also decreased in those with the most severe mental health symptoms after COVID-19. In an untargeted analysis, 5 additional metabolic pathways significantly differed based on subsequent development of GI symptoms. In the second cohort (n = 39), plasma 5-HT concentration at the time of COVID-19 was increased 5.1-fold in those with GI symptoms alone compared with those with mental health symptoms alone ( P = 0.02). DISCUSSION: Acute gut microbiome-mediated reduction in 5-HT signaling may contribute to long-term GI and mental health symptoms after COVID-19. Future studies should explore modification of 5-HT signaling to reduce post-COVID symptoms
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