Do smaller classes mean greater academic achievement in high school biology classes?

The purpose of this study was to determine if students in small classes would show greater academic achievement in high school biology classes. The study involved two high school biology classes, one with an enrollment of 20 students, and one with an enrollment of 25 students. Both groups of students were given pretests on the subject of invertebrates. A four week study of this topic followed. Teaching techniques and assignments were identical for the two groups. At the end of the four week study a posttest was given to all students. The results of the pre and posttest were then analyzed using both one and two tailed independent t-tests. The results of these tests showed that there was no significant difference between the two groups

Alien Registration- Awalt, William R. (Dexter, Penobscot County)

https://digitalmaine.com/alien_docs/11628/thumbnail.jp

N-demethylation of alkaloids using nanoscale zero valent iron

1 online resource (x, 48 p.) : ill. (some col.)Includes abstract.Includes bibliographical references (p. 42-48).The N-demethylation of naturally occurring opiate compounds is a necessary step in the synthesis of many pseudo-opioid pharmaceuticals. Such drugs have gained recent media attention in the fight against opiate addiction; hence, the ability to synthesize them efficiently is important. This work aims to improve the N-demethylation of alkaloid precursors through the use of zero valent nanoscale iron in a modified Polonovski reaction. Initial studies performed on dextromethorphan indicate that yields of the demethylated product using a 10 mol % loading of zero valent nanoscale iron are comparable to those achieved by using a stoichiometric amount of commercially available iron (0) dust. The preparation of zero valent nanoscale iron particles and their use in the N-demethylation of dextromethorphan will be described

Changes in biological productivity along the northwest African margin over the past 20,000 years

Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 31 (2016): 185–202, doi:10.1002/2015PA002862.The intertropical convergence zone and the African monsoon system are highly sensitive to climate forcing at orbital and millennial timescales. Both systems influence the strength and direction of the trade winds along northwest Africa and thus directly impact coastal upwelling. Sediment cores from the northwest African margin record upwelling-related changes in biological productivity connected to changes in regional and hemispheric climate. We present records of 230Th-normalized biogenic opal and Corg fluxes using a meridional transect of four cores from 19°N–31°N along the northwest African margin to examine changes in paleoproductivity since the last glacial maximum. We find large changes in biogenic fluxes synchronous with changes in eolian fluxes calculated using end-member modeling, suggesting that paleoproductivity and dust fluxes were strongly coupled, likely linked by changes in wind strength. Opal and Corg fluxes increase at all sites during Heinrich Stadial 1 and the Younger Dryas, consistent with an overall intensification of the trade winds, and changes in the meridional flux gradient indicate a southward wind shift at these times. Biogenic fluxes were lowest, and the meridional flux gradients were weakest during the African Humid Period when the monsoon was invigorated due to precessional changes, with greater rainfall and weaker trade winds over northwest Africa. These results expand the spatial coverage of previous paleoproxy studies showing similar changes, and they provide support for modeling studies showing changes in wind strength and direction consistent with increased upwelling during abrupt coolings and decreased upwelling during the African Humid Period.NSF Grant Numbers: OCE-1103262, OCE-1030784, OCE-0402348; Center for Climate and Life2016-07-2

ElectrochemicalN-demethylation of tropane alkaloids

A practical, efficient, and selective electrochemicalN-demethylation method of tropane alkaloids to their nortropane derivatives is described. Nortropanes, such as noratropine and norscopolamine, are important intermediates for the semi-synthesis of the medicines ipratropium or oxitropium bromide, respectively. Synthesis was performed in a simple home-made electrochemical batch cell using a porous glassy carbon electrode. The reaction proceeds at room temperature in one step in a mixture of ethanol or methanol and water. The method avoids hazardous oxidizing agents such as H(2)O(2)orm-chloroperbenzoic acid (m-CPBA), toxic solvents such as chloroform, as well as metal-based catalysts. Various key parameters were investigated in electrochemical batch or flow cells, and the optimized conditions were used in batch and flow-cells at gram scale to synthesize noratropine in high yield and purity using a convenient liquid-liquid extraction method without any need for chromatographic purification. Mechanistic studies showed that the electrochemicalN-demethylation proceeds by the formation of an iminium intermediate which is converted by water as the nucleophile. The optimized method was further applied to scopolamine, cocaine, benzatropine, homatropine and tropacocaine, showing that this is a generic way ofN-demethylating tropane alkaloids to synthesize valuable precursors for pharmaceutical products

Moving from the classroom to online teaching: a study of change in faculty attitudes

textMuch research exists on both the administrative and student issues of distance education. But there is little research on the perceptions and experiences of faculty who teach in online environments. This study focuses on what faculty experienced as they began to use the Internet as a medium for teaching and learning. In particular, this study explored faculty perceptions of changes in their teaching practices as a result of teaching online in five different graduate programs. This information may help other educators to understand the critical factors in the design of both effective training and support of faculty who teach online courses. This study also provides practical guidelines to help those who train faculty in online pedagogy and instructional designers.Curriculum and Instructio

A Comparison of Constituents in Two Essential Oils

A Comparison of Constituents in Two Essential Oil

In July 2008, the Swan\u27s Island library was destroyed by a lightening strike. T

In July 2008, the Swan\u27s Island library was destroyed by a lightening strike. The author, artist Liz Awalt, gathered burnt book pages and started the New Pages project. Maine artists created original work on the scorched pages, which were then auctioned off, netting over $46,000. Work on the new library, a project expected to cost$1.2 million, will begin this summer