Trace and Body Fossils from the Cuyahoga Formation (Mississippian), Reynoldsburg, Ohio

Seven trace fossil genera and four body fossil genera have been found in the sandstone facies (Buena Vista Member) of the Cuyahoga Formation (Lower Mississippian) at Pine Quarry Park in Reynoldsburg, Ohio. Ichnogenera identified are Scalarituba, Gordia, Zoophycos, Helminthoidia, Phycosiphon, Planolites, and Laevicyclus. Zoophycos and Laevicyclus are found in the lower beds; Gordia and Helminthoidia are more common in the upper beds. Scalarituba and Planolites are found throughout the beds. Together, the trace fossils of the upper part of the quarry are indicative of the Cruziana ichnofacies. Lower in the section the facies seems to be of the Skolithos ichnofacies. Associated body fossils found are Platycrinities sp., Gilbertsocrinus? sp., Dictyoclostus sp., Fenestrellina sp., and unidentifiable blastoid fragments. At the Reynoldsburg locality, deposition is interpreted to have taken place in a shallow water setting near an ancient deltaic environment

A Determination of Attitudes Toward Instructional Media at Eastern Illinois University

No abstract provided by author

A multiple scales approach to crack front waves

Perturbation of a propagating crack with a straight edge is solved using the method of matched asymptotic expansions (MAE). This provides a simplified analysis in which the inner and outer solutions are governed by distinct mechanics. The inner solution contains the explicit perturbation and is governed by a quasi-static equation. The outer solution determines the radiation of energy away from the tip, and requires solving dynamic equations in the unperturbed configuration. The outer and inner expansions are matched via the small parameter L/l defined by the disparate length scales: the crack perturbation length L and the outer length scale l associated with the loading. The method is first illustrated for a scalar crack model and then applied to the elastodynamic mode I problem. The dispersion relation for crack front waves is found by requiring that the energy release rate is unaltered under perturbation. The wave speed is calculated as a function of the nondimensional parameter kl where k is the crack front wavenumber, and dispersive properties of the crack front wave speed are described for the first time. The example problems considered here demonstrate that the potential of using MAE for moving boundary value problems with multiple scales.Comment: 25 pages, 5 figure

Birds of Santa Teresa, Espírito Santo, Brazil: do humans add or subtract species?

In uplands and lowlands of Santa Teresa, central Espírito Santo State, Brazil, 405 bird species were confirmed by field, museum, and literature studies. Of these, 16 seem to have disappeared, while 67 other species seem to have been lost from the lowlands (where no large biological reserves exist). Due to a suggestion that human areas add species to beta-diversity, we verified that up to 79 species now present have perhaps "invaded" with human activity (and 10 others are likely to invade), a total similar to that for lost species. However, lost species are often rare and invading species often widespread, resulting in exchange of "Picassos for Coca-Cola bottles." Furthermore, gains exceed losses only when large biological reserves are present, as in the uplands (Nova Lombardia, Santa Lúcia Reserves, each with over 250 species). Small or irregular reserves usually lose well over half their species, and these are only partly replaced by the invaders, resulting in net losses of up to half the local avifaunas. If one lists only 31 probable invaders, rather than a possible 79, things are even worse; net losses occur even in the entire township and near reserves, reaching over 200 species around lowland private reserves. Future "productive" development of human areas can eliminate or maltreat many invading species, too. While approving taxes on improductive use of land, as it leaves other areas free, we suggest that many current local "uses," such as for coffee, are "luxury" production and could be taxed.Nas terras altas e baixas de Santa Teresa, região central do Estado de Espírito Santo, Brasil, 405 espécies de aves foram confirmadas por estudos de campo, museu e de literatura. Destas, 16 parecem ter desaparecido, enquanto outras 67 espécies parecem ter sido perdidas nas baixadas (onde não existem reservas biológicas de grande extensão). Baseado na sugestão de que as áreas humanas adicionam espécies à beta diversidade, nós verificamos que até 79 espécies ora presentes talvez possam ter "invadido" junto com as atividades humanas (e outras 10 provavelmente invadirão), um total semelhante àquele de espécies perdidas. Entretanto, as espécies perdidas são freqüentemente raras e as espécies invasoras são freqüentemente de distribuições amplas, resultando em troca de "Picassos por garrafas de Coca Cola". Ademais, os ganhos excedem as perdas somente quando extensas áreas de reservas biológicas estão disponíveis, como nas terras altas (Reservas de Nova Lombardia e Santa Lúcia, cada uma com mais de 250 espécies). Reservas pequenas ou irregulares geralmente perdem mais que a metade de suas espécies, sendo estas somente parcialmente substituídas pelas invasoras, resultando em uma perda líquida de até metade da avifauna local. Se listarmos somente as 31 espécies provavelmente invasoras, ao invés das 79 possíveis, a situação torna-se ainda pior; a perda líquida ocorre até mesmo em todo o município e áreas próximas às reservas, alcançando mais de 200 espécies em torno das reservas privadas da baixada. Um desenvolvimento futuro "produtivo" de áreas humanas pode também eliminar ou maltratar muitas espécies invasoras. Aprovando-se impostos sobre o uso improdutivo das terras, deixando-se outras áreas livres, nós sugerimos que muitos dos "usos" locais atuais, como as plantações de café, são produções de "luxo" e poderiam ser taxadas

Lenticels are sites of initiation of microcracking and russeting in ‘Apple’ mango

The mango cultivar ‘Apple’ is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. ‘Apple’ mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. ‘Apple’ had fewer, larger lenticels and more russet, compared with ‘Ngowe’, ‘Kitovu’ or ‘Tommy Atkins’ mango. In cv. ‘Apple’, the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in ‘Apple’ mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture

Surface Moisture Induces Microcracks and Increases Water Vapor Permeance of Fruit Skins of Mango cv. Apple

Exposure to surface moisture triggers cuticular microcracking of the fruit skin. In mango fruit cv. apple, microcracking compromises postharvest performance by increasing moisture loss and infections with pathogens. This study reports the effects of exposing the fruit’s skin to surface moisture on the incidence of microcracking and on water vapor permeance. Microcracking was quantified microscopically following infiltration with a fluorescent tracer. Water mass loss was determined gravimetrically. Moisture exposure increased cuticular microcracking and permeance. During moisture exposure, permeance increased over the first 4 d, remained constant up to approximately 8 d, then decreased for longer exposure times. Fruit development followed a sigmoid growth pattern. The growth rate peaked approximately 103 days after full bloom. This coincided with the peak in moisture-induced microcracking. There were no increases in water vapor permeance or in microcracking in control fruit that remained dry. When experimental moisture exposure was terminated, microcracking and water vapor permeance decreased. This suggests a repair process restoring the barrier properties of the fruit skin. Histological analyses reveal a periderm forms in the hypodermis beneath a microcrack. Our study demonstrates that surface moisture induces microcracking in mango cv. apple that increases the skin’s water vapor permeance and induces russeting