Microstructure of Nunas: Andean Popping Beans (Phaseolus Vulgaris L.)

Nunas, popping beans (Phaseous vulgaris L.), burst and expand when heated rapidly. Differences in seed microstructure between popping and conventional (non-popping) bean genotypes conceivably contribute to popping in nunas However, the microstructural characteristics which contribute to the popping attribute and sites of expansion have not been identified. Seeds and excised cotyledons of unpopped and popped nunas were examined using scanning electron microscopy (SEM). Protoplasts of unpopped nunas were similar to protoplasts of conventional beans. Intercellular spaces of unpopped nunas were occluded by schizogenous cell walls. The occluded form of intercellular spaces differed distinctively from the open form in popped nunas and untreated conventional beans. The expansion of cotyledon mesophyll in popped nunas came primarily from expansion of cell walls and secondarily by expansion of the intercellular spaces. Cell wall thickness and dimensions of protoplasts were not changed during popping. Expansion of cell walls away from protoplasts created intracellular voids. SEM images indicated that starch granules (grains) in popped nunas were generally not altered by popping. Starch granules did not gelatinize or melt during popping as indicated by retention of birefringence. In contrast to popcorn (Zea mays L.), starch granules did not contribute to expansion of popped nuna cotyledons

Cellular Rupture and Release of Protoplasm and Protein Bodies From Bean and Pea Cotyledons During Imbibition

Imbibition is a critical phase in germination and processing of legume seeds because cellular disruption during imbibition may influence seedling vigor and processing quality Cellular disruption of cotyledonary surfaces of beans (Phaseolus vulgaris L.) and peas (Pisum sacivum L.) and the cellular contents released during imbibition were examined with scanning electron microscopy. Two types of c e llular disruption we r e observed during imbibition: ruptures and fractures. Individual cells and small groups of cells on t he surfnces of cotyledons ruptured after immersion in water. Ruptured cells had flaps of cell walls which remained attached to intact portions of cell walls. Fractured cells sp l it in half, and remnant portions of cell walls were completely separated from each other. Disrupted cells on the interior surfaces of blister cavities were of the fractured type. Materials released from cotyledonary tissues consisted of both dense aggregates of protein bodies and a dispersed phase of protoplasm. In some cases, protoplasm and protein bodies on cotyledonary surfaces were found adjacent to single cell ruptures and, in others, the sites of losses were not found. The presence of protoplasm and protein bodies and absence of sites for their release indicate an additions 1 mechanism other than fracture or rupture may contribute co losses of intracellular substances during imbibition

Asclepias dynamics on US rangelands: implications for conservation of monarch butterflies and other insects

The genesis of this study is in response to the United States (US) Fish and Wildlife Service (USFWS) listing of the monarch butterfly (Danaus plexippus plexippus) on 17 December 2020 in the US Federal Register as a candidate species under the Endangered Species Act of 1973. Annual censuses have identified that the eastern and western North American monarch migratory populations have been generally declining over the last 20 yr due to a myriad of environmental factors. Monarch reproduction at the larval stage is dependent on the presence of milkweed (Asclepias) plant species. The United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) National Resource Inventory rangeland data set (~23,400 on-site samples; 2032 sites with milkweed presence) was used to evaluate milkweed species densities, geolocations, and environmental gradients. Twenty-two milkweed species were identified on rangelands across 17 sampled US western states, with seven species comprising 65.5% of milkweed frequency of occurrence. The most dominant milkweed species on non-federal rangelands were Asclepias viridis, A. syriaca, A. verticillata, and A. speciosa (constancy >10% where milkweed was present). Asclepias speciosa was the dominant species from the standpoint of total plant density for the data set, whereas A. viridis was the most frequently occurring species. Total milkweed density estimates based on low, midpoint, and high estimates were 1.3, 4.1, and 6.9 B plants on 13.2 M ha. Seven US states (Kansas, Texas, Nebraska, South Dakota, North Dakota, Oklahoma, and Montana) contained 88.8% of the total estimated ha with milkweed presence. In the Central Great Plains, Northwestern Great Plains, Nebraska Sand Hills, and Flint Hills, Southwestern Tablelands, High Plains, Northwestern Glaciated Plains, and Cross Timbers, Omernik level III ecoregions contained 76.7% of the estimated milkweed plants. Milkweed species density was highest at latitude N35-40 with decreasing populations toward south (N25-30) and north (N45-50) latitudes. Milkweed species densities were greatest at longitude W-95-100 and decreased toward the western US with lowest population numbers at W-120-125. Analysis of environmental variables showed milkweed species dominance on mollisols, non-saline sites, neutral pH, well-drained soils, loam and sandy loam soil textures, and sites with soil organic matter at 1.5–3%. Disturbance gradients and habitat dynamics relating to ecological condition and rangeland health differed among the dominant milkweed species identified in this study.This article is published as Spaeth Jr, Kenneth E., Philip J. Barbour, Ray Moranz, Stephen J. Dinsmore, and C. Jason Williams. "Asclepias dynamics on US rangelands: implications for conservation of monarch butterflies and other insects." Ecosphere 13, no. 1 (2022): e03816. doi:10.1002/ecs2.3816. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted

Microstructure of nuñas: Andean popping beans (Phaseolus vulgaris L.)

Nuñas, popping beans (Phaseolus vulgaris L.), burst and expand when heated rapidly. Differences in seed microstructure between popping and conventional (non-popping) bean genotypes conceivably contribute to popping in ñuñas. However, the microstructural characteristics which contribute to the popping attribute and sites of expansion have not been identified. Seeds and excised cotyledons of unpopped and popped ñuñas were examined using scanning electron microscopy (SEM). Protoplasts of unpopped ñuñas were similar to protoplasts of conventional beans. Intercellular spaces of unpopped ñuñas were occuled by schizogenous cell walls. The occluded form of intercellular spaces differed distinctively from the open form in popped ñuñas and untreated conventional beans. The expansion of cotyledon mesophyll in popped ñuñas came primarily from expansion of cell walls and secondarily by expansion of the intercellular spaces. Cell wall thickness and dimensions of protoplasts were not changed during popping. Expansion of cell walls away from protoplasts created intracellular voids. SEM images indicated that starch granules (grains) in popped ñuñas were generally not altered by popping. Starch granules did not gelatinize or melt during popping as indicated by retention of birefringence. In contrast to popcorn (Zea mays L.), starch granules did not contribute to expansion of popped ñuña cotyledon

The Risk of Intraocular Pressure Elevation in Pediatric Noninfectious Uveitis

PURPOSE: To characterize the risk and risk factors for intraocular pressure (IOP) elevation in pediatric non-infectious uveitis. DESIGN: Multi-center retrospective cohort study. PARTICIPANTS: Nine hundred sixteen children (1593 eyes) <18 years old at presentation with non-infectious uveitis followed between January 1978 through December 2007 at five academic uveitis centers in United States. METHODS: Medical records review by trained, certified experts. MAIN OUTCOME MEASURES: Prevalence and incidence of IOP≥21 and ≥30mmHg and incidence of a rise in IOP by ≥10mmHg. To avoid under ascertainment, outcomes were counted as present when IOP-lowering therapies were in use. RESULTS: Initially 251 (15.8%) and 46 eyes (2.9%) had IOP≥21 and ≥30mmHg, respectively. Factors associated with presenting IOP elevation included age 6–12 years (versus other pediatric ages), prior cataract surgery (adjusted odds ratio≥21mmHg [aOR21]=2.42, P=0.01), pars plana vitrectomy (adjusted odds ratio≥30mmHg[aOR30]=11.1, P=0.03), duration of uveitis ≥6 months (aORs30 up to 11.8, P<0.001), contralateral IOP elevation (aOR21=16.9, aOR30=8.29; each P<0.001), visual acuity worse than 20/40 (aORs21 up to 1.73, P=0.02; aORs30 up to 2.81 P=0.03), and topical corticosteroid use (aORs up to 8.92, P<0.001 in a dose-response relationship). The median follow-up was 1.25 years (interquartile range 0.4–3.66). The estimated risk of any observed IOP elevation to ≥21 mmHg, ≥30 mmHg and of a rise in IOP by ≥10mmHg was 33.4%, 14.8% and 24.4% respectively within 2 years. Factors associated with IOP elevation included pars plana vitrectomy (adjusted hazard ratio≥21mmHg[aHR21]=3.36, P<0.001), contralateral IOP elevation (aHRs up to 9.54, P<0.001), the use of topical (aHRs up to 8.77 that followed a dose-response relationship, P<0.001), periocular (aHRs up to 7.96, P<0.001) and intraocular (aHRs up to 19.7, P<0.001) corticosteroids. CONCLUSIONS: IOP elevation affects a large minority of children with non-infectious uveitis. Statistically significant risk factors include IOP elevation or use of IOP-lowering treatment in the contralateral eye and local corticosteroid use – that demonstrated a dose-and route of administration-dependent relationship. In contrast, use of immunosuppressive drug therapy did not increase such risk. Pediatric eyes with non-infectious uveitis should be followed closely for IOP elevation when strong risk factors such as the use of local corticosteroids and contralateral IOP elevation are present