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1.
Ecol Lett ; 27(4): e14425, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38577899

ABSTRACT

Plants interact in complex networks but how network structure depends on resources, natural enemies and species resource-use strategy remains poorly understood. Here, we quantified competition networks among 18 plants varying in fast-slow strategy, by testing how increased nutrient availability and reduced foliar pathogens affected intra- and inter-specific interactions. Our results show that nitrogen and pathogens altered several aspects of network structure, often in unexpected ways due to fast and slow growing species responding differently. Nitrogen addition increased competition asymmetry in slow growing networks, as expected, but decreased it in fast growing networks. Pathogen reduction made networks more even and less skewed because pathogens targeted weaker competitors. Surprisingly, pathogens and nitrogen dampened each other's effect. Our results show that plant growth strategy is key to understand how competition respond to resources and enemies, a prediction from classic theories which has rarely been tested by linking functional traits to competition networks.


Subject(s)
Nitrogen , Plants
2.
Sleep Med ; 90: 135-141, 2022 02.
Article in English | MEDLINE | ID: mdl-35158293

ABSTRACT

OBJECTIVE/BACKGROUND: This retrospective non-randomized controlled cohort study aimed to evaluate the efficiency of simultaneous maxillary expansion and mandibular advancement for the management of pediatric OSAS. PATIENTS/METHODS: The sample was composed of 94 children treated with an innovative orthopedic device to correct a Class II malocclusion associated with an OSAS. Polysomnographic recordings were performed before and after the treatment. We also included a group of 113 age-matched control patients who had the same pathologies, but who did not receive the orthopedic treatment at the time they undergone polysomnographic exams. Statistical tests evaluated the significance of the evolution of these data, both in treated and untreated control patients. RESULTS: After nine months (±3 months) of treatment, respiratory OSAS symptoms significantly improved: the AHI significantly decreased as it became inferior to the pathological threshold (<1) for 53% of the treated patients' sample, with a greater proportion within the youngest age group (63%). Only two patients still presented a moderate OSAS after treatment, with an AHI slightly superior to 5. This positive evolution of OSAS respiratory symptoms was not observed within the control group, highlighting the real impact of the orthopedic treatment over the children's natural growth. However, sleep remained fragmented following the treatment. CONCLUSIONS: This study confirmed that simultaneous maxillary expansion and mandibular advancement induced a modification of the maxilla-mandibular anatomy, helping in the significant improvement of the respiratory OSAS symptoms. Then, considering these preliminary results, pediatric OSAS can be managed with this new orthopedic strategy, especially if it is performed early.


Subject(s)
Maxilla , Sleep Apnea, Obstructive , Child , Cohort Studies , Humans , Mandible , Polysomnography/methods , Retrospective Studies , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/surgery
3.
Plant Physiol Biochem ; 151: 10-20, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32179468

ABSTRACT

Soldanella alpina differing in leaf epidermal UV-A absorbance (DEA375), as measured with the Dualex, was investigated as a model alpine plant for the flavonoid (Flav) composition and concentration and for anatomical and pigment characteristics. In sun leaves, twenty-three flavones were characterised by their mass formula, their maximum absorption, their glycosylation, their methylation and dehydroxylation pattern. The flavones belonged to four subfamilies (tetra-hydroxy-flavones, penta-hydroxy-flavones, penta-hydroxy-methyl-flavones and tri-hydroxy-di-methoxy-flavones), abundant in sun and shade leaves. Their concentration was estimated by their absorption at 350 nm after HPLC separation. Sun leaves contained relatively higher contents of penta-hydroxy-methyl-flavones and shade leaves higher contents of tetra-hydroxy-flavones. The flavones were present mainly in vacuoles, all over the leaf. After shade-sun transfer, the content of most flavones increased, irrespective of the presence or absence of UV radiation. Highly significant correlations with the log-transformed DEA375 suggest that DEA375 can be readily applied to predict the flavone content of S. alpina leaves. Shade-sun transfer of leaves decreased the hydroxycinnamic acid (HCA) content, the mass-based chlorophyll (Chl) a+b content and the Chl/Carotenoid (Car) ratio but increased DEA375, and the Car content. Together with previously reported anatomical characteristics all these parameters correlated significantly with the DEA375. The Flav content is therefore correlated to most of the structural characteristics of leaf acclimation to light and this can be probed in situ by DEA375.


Subject(s)
Acclimatization , Plant Leaves/physiology , Primulaceae/physiology , Ultraviolet Rays , Carotenoids/analysis , Chlorophyll/analysis , Flavonoids/analysis , Photosynthesis , Plant Leaves/radiation effects , Primulaceae/radiation effects , Sunlight
4.
Ann Allergy Asthma Immunol ; 119(2): 177-183, 2017 08.
Article in English | MEDLINE | ID: mdl-28676207

ABSTRACT

BACKGROUND: In children with eosinophilic esophagitis (EoE) foods are the most common disease triggers, but environmental allergens are also suspected culprits. OBJECTIVE: To determine the effects of environmental allergen sensitization on response to treatment in children with EoE in the southeastern United States. METHODS: Patients 2 to 18 years old who were referred to the Arkansas Children's Hospital Eosinophilic Gastrointestinal Disorders Clinic from January 2012 to January 2016 were enrolled in a prospective, longitudinal cohort study with collection of demographics, clinical symptoms, medical history, allergy sensitization profiles, and response to treatment over time. Comparisons were made between complete responders (peak esophageal eosinophil count <15 per high-power field [HPF]) and nonresponders (>25 eosinophils per HPF) after treatment with diet elimination alone, swallowed corticosteroids alone, or diet elimination and swallowed corticosteroids. Sensitization patterns to environmental allergens found in the southeastern United States were analyzed for the effect on treatment response. RESULTS: A total of 223 individuals were enrolled. Of these, 182 had environmental allergy profiling and at least one endoscopy while receiving proton pump inhibitor (PPI) therapy. Twenty-nine individuals had PPI-responsive EoE and were excluded from further analysis, leaving 123 individuals with non-PPI-responsive EoE who were further analyzed; 72 (58.5%) were complete responders and 33 (26.8%) were nonresponders. Seventeen individuals (13.8%) were partial responders (≥1 but ≤25 eosinophils per HPF) and excluded from further analysis. Nonresponders were more likely to be sensitized to perennial allergens (P = .02). There was no significant difference in response based on seasonal allergen sensitization. Individuals with mold or cockroach sensitization were more likely to fail combination diet and swallowed corticosteroid treatment (P = .02 and P = .002). CONCLUSION: Perennial allergen and mold sensitization may lead to nonresponse to EoE treatment in some patients. Additional studies are needed to further understand the effect of environmental allergens on EoE. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01779154.


Subject(s)
Allergens/immunology , Eosinophilic Esophagitis/immunology , Eosinophilic Esophagitis/therapy , Eosinophils/immunology , Esophagus/pathology , Hypersensitivity/immunology , Hypersensitivity/pathology , Adolescent , Arkansas , Child , Child, Preschool , Environmental Exposure , Female , Humans , Immunization/adverse effects , Longitudinal Studies , Male , Particulate Matter/immunology , Prospective Studies , Proton Pump Inhibitors/therapeutic use , Seasons , Treatment Outcome
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