Plant functionality across an environmental gradient

Community assemblages provide insight into ecosystem processes, both spatially and temporally. They interact with biotic and abiotic factors that vary with habitat structure, influencing community composition. Ecological theory demonstrates that species have the potential for a wide fundamental niche, but habitat range may be restricted by factors exposed to species in their realized niche. In barrier island ecosystems, edaphic and environmental characteristics (e.g. elevation and distance to shoreline) are major drivers determining where and how plant communities establish. Physical stressors, such as salt stress and drought influence community grouping and can alter plant function within the environment. With projected increases in sea level rise and storm disturbance it is important to understand how plant communities are organized across barrier islands, as most studies are limited to dune habitats and not inland plant communities. I analyzed plant communities across environmental gradients on a Virginia barrier island from dune to marsh. I established transects on Hog Island and assessed soil characteristics (i.e. carbon, nitrogen, pH), species composition, percent cover and specific leaf area. Elevation and distance to shoreline were obtained using recent Lidar imagery. Bray-Curtis ordination showed that position in landscape is an important driver in structuring dominant species such as the grasses Ammophila breviligulata, Spartina patens, and S. alterniflora. Elevation (r = -0.511) and distance to shoreline (r = 0.551) both show relationships with species composition and distribution across the island. Elevation was important in structuring dominant community types (i.e. dune building and marsh plants). Mantel test was used to determine if relationship exists between species cover and measured edaphic/environmental factors (r = 0.299, p \u3e 0.0001). Percent carbon found in soil within plots was weakly related with distance to the inner portion of the island (r = 0.56). This reflects biotic processes that occur in interior portions of the island. There was no obvious relationship with percent nitrogen due to extremely low levels across the ecosystem. Understanding community structure across coastal ecosystems is necessary for predicting how shorelines and interior communities will be affected with projected sea level rise and increases in storm frequencies. An updated understanding of how biotic and abiotic drivers of community composition will provide information into predictive modeling of plant community and ecosystem level responses to change.https://scholarscompass.vcu.edu/uresposters/1219/thumbnail.jp

Sensitivity to Ingested Sulfites

Sulfiting agents, including sodium and potassium bisulfite, sodium and potassium metabisulfite, sodium sulfite, and sulfur dioxide, have enjoyed widespread use as food and drug ingredients. The oral ingestion of these sulfiting agents is now known to trigger asthma in a small subset of the asthmatic population. The best evidence suggests that perhaps 150,000 to 200,000 individuals in the United States may be sulfite sensitive. Although the mechanism of sulfite-induced asthma remains unknown, several possibilities have been considered, including inhalation of sulfur dioxide (SO2) while swallowing, an IgE-mediated reaction, and a deficiency of sulfite oxidase leading to impaired sulfite metabolism and excretion. The only treatment for sulfite sensitivity is avoidance of sulfites in foods and drugs

Dordrechtites Arcanus Sp. Nov., An Anatomically Preserved Gymnospermous Reproductive Structure From the Middle Triassic of Antarctica

This is the publisher's version of an article which is being shared with permission. The original version may be accessed at: http://dx.doi.org/10.1086/668792The genus Dordrechtites is an isolated ovulate structure previously described only from South Africa and Australia as impressions. The discovery of compressed and permineralized specimens of this taxon at the base of Mount Falla (uppermost Fremouw Formation) in the central Transantarctic Mountains extends the geographical and geological distribution of the genus and increases the known floral diversity of the Triassic of Antarctica. The first permineralized species, Dordrechtites arcanus, is described using standard acetate peel techniques and includes internal anatomy of an elongate arm that extends over the top of a central cupule containing two elongate, bilaterally symmetrical, orthotropous ovules. An arc-shaped collateral vascular bundle extends from the arm into the top of the cupule, branches, and then extends around the ovule to about halfway down to the micropylar end. The cupule is parenchymatous and includes transfusion tissue with cells that have pitted walls. The sclerotesta of the ovule is up to 200 mm thick, consisting of an outer layer with longitudinally oriented, thick-walled cells and an inner layer one cell thick of rectangular, thick-walled cells. The micropyle is flared at the attenuated tip of the pyramidal cupule. The four previously described species of Dordrechtites have uncertain affinities, and although the morphology and anatomy of this taxon is now known, the affinities within the gymnosperms are still uncertain

Allergenic Foods

Virtually all food allergens are proteins, although only a small percentage of the many proteins in foods are allergens. Any food that contains protein has the potential to cause allergic reactions in some individuals. However, a few foods or food groups are known to cause allergies on a more frequent basis than other foods. At a 1995 consultation on food allergies sponsored by the Food and Agriculture Organization, a group of international experts confirmed that peanuts, soybeans, crustacea, fish, cow’s milk, eggs, tree nuts, and wheat are the most common allergenic foods. These foods are responsible for more than 90% of serious allergic reactions to foods. Allergies to certain fresh fruits and vegetables are also rather common, but the allergens tend to be labile to processing and cooking and the symptoms are mild and confined primarily to the oropharyngeal area. The prevalence of allergic sensitivities to specific foods varies from one country to another depending on the frequency with which the food is eaten in that country and the typical age at its introduction into the diet. For example, peanuts are a much more frequent cause of food allergies in the United States than in most other countries. Americans eat peanuts more often and introduce peanut butter into the diet of children at an early age. The Japanese probably experience more soybean and rice allergies than some other cultures because of the frequency of these two foods in the Japanese diet. Scandinavians have a high incidence of codfish allergy for similar reasons. Table 1 provides a listing of the most common allergenic foods and food groups compiled from a thorough search of the medical literature. Table 2 provides a listing of the less common allergenic foods. Only some of the foods listed in this table have been documented to cause severe, life-threatening allergic reactions. Citations are provided to studies and/or case reports that document the allergenicity of those particular foods. The absence of a particular food on this list may not mean that it is nonallergenic but may indicate that its allergenicity has not been documented. Conversely, the presence of a specific food on the list merely indicates that it has been listed in one or more reports as a cause of food allergy and does not indicate the prevalence or potential as an allergenic food

Sulfites

Key Concepts Sulfites are frequently used food and drug additives. Ingestion of sulfite residues has been documented to trigger asthmatic reactions in sensitive individuals. Sulfite-induced asthma occurs in less than 5% of asthmatic individuals, and those with severe, persistent asthma are at greatest risk. The diagnosis of sulfite-induced asthma is best made by blinded oral challenge with assessment of lung function. Labeling regulations in the United States alert sulfite-sensitive individuals to the presence of sulfites in foods, which must then be avoided

Sulfite Residues in Maraschino Cherries

A survey of 53 samples of maraschino cherries from 14 different processors revealed that total sulfite residues averaged 52.3 ± 44.7 ppm. However, 58.5% of the samples had less than 40 ppm total SO2, while only 7.6% had greater than 120 ppm total SO2 indicating that the distribution was skewed in the direction of lower residue levels. Free sulfite residues in the 53 samples were considerably lower, averaging 14.2 ± 7.1 ppm. With free SO2 levels, 35.8% of the samples had less than 10 ppm free SO2, while only 5.7% had greater than 30 ppm free SO2. With an average serving size of one cherry (3–7 g), maraschino cherries would contribute only 0.16–0.37 mg per serving of total sulfites as SO2

Evaluation of a Handheld Gluten Detection Device

A portable, handheld gluten detection device, the Nima sensor, is now available for consumers wishing to determine if gluten is present in food. By U.S. regulation, gluten-free foods should contain \u3c 20 ppm of gluten. Thirteen gluten-free foods (muffins, three different types of bread, three different types of pasta, puffed corn snack, ice cream, meatballs, vinegar and oil salad dressing, oatmeal, and dark chocolate) were prepared; each food was spiked on a weight-to-weight basis with gluten levels of 0, 5, 10, 20, 30, 40, and 100 ppm before processing or preparation. Unprocessed and processed foods were tested with the handheld gluten sensor and by two gluten-specific enzyme-linked immunosorbent assays (ELISAs) on the basis of the R5 and G12 monoclonal antibodies, respectively. The portable gluten detection device detected gluten in all food types at the 30-ppm addition level, failing to detect gluten in only 5 (6.4%) of 78 subsamples. At the 20-ppm addition level, the portable gluten detection device failed to detect gluten in one type of pasta but detected gluten residues in 63 (87.5%) of 72 other subsamples. The device was able to detect gluten at the 10-ppm addition level in 9 of the 13 food matrices (41 of 54 subsamples, 75.9%) but not in the three types of pasta and the puffed corn snack. The gluten-sensing device did not perform reliably at the 5-ppm addition level in 11 of 13 food matrices (exceptions: ice cream and muffins). In contrast, the ELISA methods were highly reliable at gluten addition levels of ≥ 10 ppm in all food matrices. The portable gluten detection device yielded a low percentage of false-positive results (4 of 111, 3.6%) in these food matrices. Thus, this handheld portable gluten sensor performed reliably in the detection of gluten in foods having ≥ 20 ppm of added gluten with only 18 (5.9%) of 306 failures, if results of the one type of pasta are excluded. The device worked with greater reliability as the gluten levels in the foods increased

Soybean Oil Is Not Allergenic to Soybean-Sensitive Individuals

We have previously demonstrated that peanut oil is not allergenic to peanut-sensitive individuals. Seven soybean-sensitive patients were enrolled in a double-blind crossover study to determine whether ingestion of soybean oil can induce adverse reactions in such patients. All subjects had histories of systemic allergic reactions (urticaria, angioedema, wheezing, dyspnea, and/or vomiting) after soybean ingestion and had positive puncture skin tests with a 1:20 w/v glycerinated-saline whole soybean extract. Sera from six of the seven subjects were tested by RAST assay for the presence of specific IgE antibodies to soybean allergens. All patients had elevated levels of serum IgE antibodies to the crude soybean extract; binding values ranged from 2.3 to 28.1 times that of a negative control serum. Before the oral challenges, all patients demonstrated negative puncture skin tests to three commercially available soybean oils and to olive oil (control). On four separate days, patients were challenged with the individual soybean oils and to olive oil in random sequence. At 30-minute intervals, under constant observation, patients ingested 2, 5, and 8 ml of one of the soybean oils or olive oil contained in 1 ml capsules. No untoward reactions were observed with either the commercially available soybean oils or olive oil. Soybean oil ingestion does not appear to pose a risk to soybean-sensitive individuals

Book Reviews

Julie Nichols - Reading Ethically Peter Fields - Gregory Marshall. Shaped by Stories: The Ethical Power of Narratives. Notre Dame, IN: U of Notre Dame P., 2009 Walter L. Reed - Gregory, Marshall. Teaching Excellence in Higher Education, ed. Melissa Valiska Gregory. NY: Palgrave Macmillan, 2013 Jeffrey H. Taylor - Musgrove, Laurence. Local Bird. Beaumont, TX: Lamar U Press, 2015 Warren Hatch - Lynch, Tom, Cheryll Glotfelty, Karla Armbruster. The Bioregional Imagination—Literature, Ecology, and Place. Athens, GA: U of GA Press, 201