Calclium-calmodulin regulation of TRPM2 currents

TRPM2 (1507 amino acids), a non-selective cation channel with substantial permeability for Ca2+, is responsive to oxidative stress, and is a mediator of cell death in several cell types. Ca2+-calmodulin has been shown to promote channel activation and inactivation, however the mechanisms are not fully understood. Identifying candidate CaM binding sites using in silico screening, I hypothesized that Ca2+-dependent inactivation (CDI) of TRPM2 is mediated by an intracellular CaM binding domain unique from that of activation (406-415AA). I systematically determined the minimum binding domains for three CaM candidate sites on TRPM2’s intracellular domains using truncated fragments and subsequent CaM-Sepharose pull-downs. TRPM2 with substitution mutations to candidate sites were transfected into HEK293 cells; currents were recorded using 2mM or 0.5mM Ca2+ extracellular fluid and adenosine diphosphate ribose (ADPR) in the patch pipette. Abolished and reduced currents respectively were observed as a result of amino acid substitution to CaM binding regions at 172-187AA and 1087-1101AA of TRPM2. The two identified CaM candidate sites may establish a potential molecular link to CDI of TRPM2

Prediction of Leaf Area in Individual Leaves of Cherrybark Oak Seedlings (Quercus pagoda Raf.)

The prediction of leaf area for cherrybark oak (Quercus pagoda Raf.) seedlings is important for studying the physiology of the species. Linear and polynomial models involving leaf length, width, fresh weight, dry weight, and internodal length were tested independently and collectively to predict leaf area. Twenty-nine cherrybark oak seedlings were grown in a greenhouse for one growing season and a total of 468 leaves were collected. Leaf area was polynomially related with leaf length or width, but linearly related with the cross product of length and width. Average leaf area for flush 3 was significantly greater than those of other flushes. However, variation in leaf area among flushes did not affect the models. Relationship between leaf area and length (or width) was consistent. Since leaf length is easy to measure and does not require destruction of leaves, it can be effectively used to predict leaf area in cherrybark oak seedlings

Comparative Gas-Exchange in Leaves of Intact and Clipped, Natural and Planted Cherrybark Oak (Quercus pagoda Raf.) Seedlings

Gas-exchange measurements, including CO2 -exchange rate (net photosynthesis), stomatal conductance, and transpiration, were conducted on intact and clipped cherrybark oak (Quercus pagoda Raf.) seedlings growing in the field and in a nursery bed. Seedlings in the field, released from midstory and understory woody competition, showed significant increases in gas-exchange compared to non-released seedlings due to increases in light levels reaching seedlings. Concurrently, little difference occurred in the CO2 -exchange rate between intact and clipped seedlings in the released treatment although clipped seedlings maintained a consistently greater rate of stomatal conductance. In order to reduce the high variability of light levels recorded in the field, gas-exchange measurements were conducted on intact and clipped cherrybark oak seedlings growing in a nursery bed under consistent light conditions. Again, no differences were found in the CO2 - exchange rate between intact and clipped seedlings. Furthermore, no differences were found in stomatal conductance and transpiration between intact and clipped seedlings. However, significant differences in gas-exchange were found between first-flush and second-flush leaves regardless of seedling treatment (intact or a sprout). Greater rates of gas-exchange in second-flush leaves can be attributed to developing third-flush steams and leaves

Crown Radius and Diameter at Breast Height Relationships for Six Bottomland Hardwood Species

The relationship between a tree\u27s crown radius and diameter at breast height (DBH) has a variety of uses including forest competition studies, tree crown densities, spacing and stocking relationships, wildlife habitat suitability models, and tree volume estimations. Estimating DBH from mean crown radius (MCR) is of interest to natural resource managers because MCR can be estimated from high resolution digital imagery using remote sensing techniques. DBH is a common tree dimensional characteristic that is used to quantify tree and stand structure. This research presents MCR/DBH and DBH/MCR relationships for boxelder (Acer negundo L.), sweet pecan (Carya illinoensis (Wang) K.Koch), sugarberry (Celtis laevigata Willd.), green ash (Fraxinus pennsylvanica Marsh.), Nuttall oak (Quercus nuttallii Palmer), and American elm (Ulmus americana L.). The linear model, y =a+b * x, provided the best model fit with adjusted r values of 0.567 to 0.855 for the 6 species. Crown radius can be determined from digital imagery and then used to predict DBH

Trials and tribulations from a hardwood forestry literature junkie : the hardwood information project

This presentation and paper were presented at the 6th Biennial Conference on University Education in Natural Resources. Proceedings of that conference were not disseminated. As further work by this author was presented as an update in the 7th Biennial Conference, we have included this supplementary material in this collection as well.The Hardwood Information Project (THIP) involves the accumulation and organization of literature under the broad categories of ecology, silviculture, and management of hardwoods. The goal of THIP is to have the best collection of hardwood literature in the world located in one place in a logical and easily retrievable format. The cornerstone of THIP is Forestry Abstracts. I have developed and use a system that involves Forestry Abstracts and the National Agricultural Library to identify and retrieve hardwood and related literature for storage and future use. This system is based on lecture topics from a college course in hardwood management. I will describe THIP, including success in literature retrieval through Forestry Abstracts and the National Agricultural Library, and how articles are filed for easy retrieval and use. I also welcome suggestions for improvements to THIP.Keywords: retrieval, hardwoods, literature, continuing educatio

Using forest ecology exercises in science fairs to increase interest in forest resources education: an example from a stand development study.

Presented at the 7th Biennial Conference on University Education in Natural Resources, March 13-15, 2008, Corvallis, Oregon.Undergraduate enrollment in forest resource programs has been declining for the past 10 to 15 years, with enrollment in some programs nearing critical levels. Efforts to increase enrollment include broadening program offerings, creating new majors (especially in spatial information systems), and increasing recruiting efforts. A potential recruiting approach is working directly with junior and senior high school students (grades 7 through 12) interested in natural sciences on forest resource specific science fair projects. Greater involvement from forest resource professionals in encouraging and developing science fair projects could help reverse the declining undergraduate enrollment trend. We present an example of a stand development study presented by the junior author during a series of science fair contests. The study was conducted in northeastern Oklahoma, and utilized the stem reconstruction technique for determining age distribution and height development patterns of several hardwood species in a single plot. Hypotheses included, “the larger the tree diameter the older the tree” and “the tallest tree was always the tallest tree.” We discuss implications of using this study in science fairs, along with opportunities and limitations for other forest-based ecological studies, and how they can lead to increased interest in forest resources as a career.Keywords: forest stand development, science fairs, forest resource education, secondary schoolContact: Lockhart, B.R. 738 Airport Road Lake Village, Arkansas 71653 Cronk, B. Magellan Oil Company Knoxville, Tennessee [email protected]

Conceptual Basis for an Index of Forest Integrity for Upland Coastal Plain Ecosystems

Following the recent trend to manage natural resources for sustainability, ecologists, resource managers and policymakers are beginning to think of the management of forest ecosystems in terms of ecosystem health or ecosystem integrity. Biologists are increasingly recognizing that use of chemical assays in assessing the condition of an ecosystem has limited value, and that biological factors, e.g., species diversity and composition, can be useful characters in the analysis of biotic integrity. An index of biotic integrity (IBI) has been developed for riverine ecosystems in the Midwest U.S., using fish species diversity, indicator population analysis, trophic structure assessment, and physiological abnormalities in fish as measurable surrogates for biotic integrity . This paper explores the development of an analogous index of forest integrity (IFI) to be applied to the upland coastal plain forests of southern Arkansas and northern Louisiana. The IFI developed here includes sampling and analysis of population trends of dominant plant taxa, plant species diversity, and horizontal and vertical vegetative structure at midstory, shrub and detritus levels

Avances en la restauración de bosques de roble en tierras bajas agrícolas del Río Mississippi y sus tributarios

The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More recently, declines in agricultural commodity prices, along with increased awareness of conservation have provided opportunities to restore a substantial base of agriculture land to broadleaf forests. While afforestation of former agricultural land began over 40 years ago in the region, organized, large-scale afforestation efforts have peaked over the last 15 years with increased interest in forest sustainability, biodiversity conservation, carbon sequestration, and water quality. Large-scale implementation of afforestation to restore broadleaf forest cover has raised many issues particular to oak species biology and ecology that impact the restoration process. The purpose of this manuscript is to present knowledge gained from research and experience with oak forest afforestation in the eastern United States as a model for developing approaches to initiate oak forest restoration in other regions. To accomplish this, we outline issues associated with the oak regeneration strategy and natural stand development patterns that have hampered large-scale restoration of oak-dominated forests. Furthermore, we present effective afforestation approaches used to reduce the impact of these challenges, and frame these approaches under the context of oak forest afforestation that addresses multiple management objectives and provides for value and function on a sustainable basis.Las zonas bajas asociadas al río Mississippi y sus tributarios albergaron históricamente extensos bosques de latifoliadas particularmente ricos en especies de roble (Quercus spp.). A comienzos del siglo xviii, la deforestación causada por la agricultura sostenible redujo la extensión del bosque original y fragmentó el restante en pequeñas parcelas. Más recientemente, la reducción en los precios de los productos, junto con la creciente conciencia por la conservación, han brindado oportunidades para restaurar una porción considerable de tierras agrícolas en bosques de latifoliadas. Mientras que las primeras reforestaciones de tierras agrícolas comenzaron hace 40 años en la región, los esfuerzos para realizar reforestaciones organizadas y a gran escala han tenido su máximo en los últimos 15 años, debido al creciente interés en la sostenibilidad de los bosques, la conservación de la biodiversidad, el secuestro de carbono y la calidad de las aguas. Implementar la reforestación a gran escala para restaurar bosques de latifoliadas involucra muchos aspectos de la biología y ecología de las especies de roble que impactan el proceso de restauración. El propósito de este artículo es mostrar los conocimientos que se han obtenido a través de investigaciones y experiencias en la reforestación de bosques de roble en el oriente de los Estados Unidos, como modelo para desarrollar avances que permitan iniciar la restauración de los bosques de roble en otras regiones. Para lograr esto delineamos aspectos asociados con las estrategias de regeneración de los robles y los patrones de desarrollo natural de los rodales que han limitado la reforestación a gran escala en bosque dominados por roble. Más aún, presentamos avances efectivos en reforestación usados para reducir el impacto de estos cambios, y enmarcamos estos avances en el contexto de la reforestación de bosques de roble que responde a múltiples objetivos de manejo y brinda valor y función sobre una base sostenible