Etiopathogenetic consideration and definition of the clinical manifestation of erosive dental defects

Dental defects of erosive nature are defined as irreversible losses of dental tissue, caused by long lasting and repeated action of acids that dissolve top layer of hydroxyapatite and fluorideapatites crystal structure, under assumption that aggressive factor is not of bacterial nature. Acids that cause changes on teeth according to their origin are gastric, dietetic, or they are of environmental origin. Current way of life, as well as nutritional habits create potentially dangerous conditions for the hard dental tissue, for prevention of mineralization process causes defects of oral system homeostasis. Defects occur on primary teeth, as well as on permanent teeth. However, this happens once and a half time more frequently on primary teeth due to the weaker primary maturation. In initial phases, changes are localized in enamel and by their development the bottom locates in dentine. Defects appear as smooth, shiny, round concavities on caries immune positions, or as cupping of occlusal surfaces. The depth of an eroded lesion consists of the depth of the crater plus the depth of tissue demineralization at the base of the lesion. Early verification of the etiological factor, together with good knowledge of the manifested shape change has influence to the prevention of the crown of tooth loss, complete occlusion, mastication and speech

Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize

Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives

Characterization of Natural and Simulated Herbivory on Wild Soybean (Glycine soja Seib. et Zucc.) for Use in Ecological Risk Assessment of Insect Protected Soybean.

Insect-protected soybean (Glycine max (L.) Merr.) was developed to protect against foliage feeding by certain Lepidopteran insects. The assessment of potential consequences of transgene introgression from soybean to wild soybean (Glycine soja Seib. et Zucc.) is required as one aspect of the environmental risk assessment (ERA) in Japan. A potential hazard of insect-protected soybean may be hypothesized as transfer of a trait by gene flow to wild soybean and subsequent reduction in foliage feeding by Lepidopteran insects that result in increased weediness of wild soybean in Japan. To assess this potential hazard two studies were conducted. A three-year survey of wild soybean populations in Japan was conducted to establish basic information on foliage damage caused by different herbivores. When assessed across all populations and years within each prefecture, the total foliage from different herbivores was ≤ 30%, with the lowest levels of defoliation (< 2%) caused by Lepidopteran insects. A separate experiment using five levels of simulated defoliation (0%, 10%, 25%, 50% and 100%) was conducted to assess the impact on pod and seed production and time to maturity of wild soybean. The results indicated that there was no decrease in wild soybean plants pod or seed number or time to maturity at defoliation rates up to 50%. The results from these experiments indicate that wild soybean is not limited by lepidopteran feeding and has an ability to compensate for defoliation levels observed in nature. Therefore, the potential hazard to wild soybean from the importation of insect-protected soybean for food and feed into Japan is negligible

Habitat for wild soybean populations observed in the surveys of insect leaf feeding damage in 2011, 2012 and 2013 in Japan.

<p>Habitat for wild soybean populations observed in the surveys of insect leaf feeding damage in 2011, 2012 and 2013 in Japan.</p

Foliar damage attributed to various herbivores based on symptoms and herbivore feeding pattern.

<p>Foliar damage attributed to various herbivores based on symptoms and herbivore feeding pattern.</p

The growth stages of wild soybean at each observation time at each site during each year.

<p>Growth stages were defined as; Vegetative (VE—Vn), Flowering (R1 –R2), and Pod/seed development (R3 –R8) as described by Pedersen [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151237#pone.0151237.ref041" target="_blank">41</a>]. The date associated with the bars denotes the observation date at each site. Observation date including two different colors (<i>e</i>.<i>g</i>., 10-Aug., 2011) indicates that the growth stage of wild soybean varied among plants of the same population at that time.</p

Example of wild soybean plants at R1-R2 growth stage just prior to defoliation treatments (A) and after defoliaton treatments at the R7 growth stage (B).

<p>The number in the figure denotes the percentage of mechanical defoliation. No defoliation (0%) treatment was used as the control.</p

The number of pods produced per individual wild soybean plant after different defoliation treatments.

<p>The blue diamonds are the total number of pods per plant and the red diamonds are the mean number of pods across all plants within each defoliation treatment.</p

The number of pods and seeds per plant, days to flowering and days to early maturity of wild soybean after defoliation treatments.

<p>The number of pods and seeds per plant, days to flowering and days to early maturity of wild soybean after defoliation treatments.</p