1863-08-02 Report of the 5th Maine Battery After Gettysburg

https://digitalmaine.com/cw_me_5th_battery_corr/1000/thumbnail.jp

Microarray analysis of replicative senescence

AbstractBackground: Limited replicative capacity is a defining characteristic of most normal human cells and culminates in senescence, an arrested state in which cells remain viable but display an altered pattern of gene and protein expression. To survey widely the alterations in gene expression, we have developed a DNA microarray analysis system that contains genes previously reported to be involved in aging, as well as those involved in many of the major biochemical signaling pathways.Results: Senescence-associated gene expression was assessed in three cell types: dermal fibroblasts, retinal pigment epithelial cells, and vascular endothelial cells. Fibroblasts demonstrated a strong inflammatory-type response, but shared limited overlap in senescent gene expression patterns with the other two cell types. The characteristics of the senescence response were highly cell-type specific. A comparison of early- and late-passage cells stimulated with serum showed specific deficits in the early and mid G1 response of senescent cells. Several genes that are constitutively overexpressed in senescent fibroblasts are regulated during the cell cycle in early-passage cells, suggesting that senescent cells are locked in an activated state that mimics the early remodeling phase of wound repair.Conclusions: Replicative senescence triggers mRNA expression patterns that vary widely and cell lineage strongly influences these patterns. In fibroblasts, the senescent state mimics inflammatory wound repair processes and, as such, senescent cells may contribute to chronic wound pathologies

Tree mortality based fire severity classification for forest inventories: A Pacific Northwest national forests example

Determining how the frequency, severity, and extent of forest fires are changing in response to changes in management and climate is a key concern in many regions where fire is an important natural disturbance. In the USA the only national-scale fire severity classification uses satellite image change-detection to produce maps for large (>400 ha) fires, and is generated by the Monitoring Trends in Burn Severity (MTBS) program. It is not clear how much forested area burns in smaller fires or whether ground-based fire severity estimates from a statistical sample of all forest lands might provide additional, useful information. We developed a tree mortality based fire severity classification using remeasured tree data from 10,008 plots in a probabilistic survey of National Forests System (NFS) lands in Oregon and Washington, using 8 tree mortality and abundance metrics. We estimate that 12.5% (±0.7% SE) of NFS forest lands in the region experienced a fire event during 1993–2007, with an annual rate of 0.96% (±0.05%). An estimated 6.5% of forest lands burned at High Severity or Moderate Severity; 2.1% burned at Very Low severity or only experienced surface or understory fire. A total of 358 of the 507 burned plots were within the MTBS perimeters, with ∼45% having equivalent severity classifications; but for ∼51% of the plots the MTBS classifications suggested lower severity than the tree-mortality based classes. Based on events recorded on plots and the inventory design, we estimate that 20.9% of the forested NFS lands experiencing fires, either wildfires or prescribed burns, were not in the MTBS maps. Tree mortality based fire severity classifications, combined with remotely-sensed and management information on timing and treatments, could be readily applied to nationally-consistent Forest Inventory and Analysis (FIA) data to provide improved monitoring of fire effects anywhere in the USA sampled by remeasured FIA inventories.Keywords: Fire effects, Tree remeasurement, Wildfire, Probabilistic sampling, Forest monitoring, Forest Inventory and Analysis (FIA

Impacts of 40 Years of the Gudmundsen Sandhills Laboratory on Beef Cattle and Range Systems

The University of Nebraska (UNL) Gudmundsen Sandhills Laboratory (GSL) is a 12,800-acre research ranch in the Nebraska Sandhills. In 1978, Elmer “Pete” and Abbie Gudmundsen gifted the former Rafter C Ranch to the University of Nebraska Foundation. Thus, 2018 was the 40th year of UNL oversight of GSL. To the credit of UNL Administration, GSL development for range livestock research was delegated to a team of Research and Extension Specialists chaired by Dr. Don Clanton. Other members of that original team were Jim Nichols, Range Science; Gene Deutscher, Reproductive Physiologist; Dick Clark, Agricultural Economist; and Ivan Rush, Beef Extension Specialist. This team configured the ranch to investigate production and management questions pertinent to the region

Carbon stocks and accumulation rates in Pacific Northwest forests: role of stand age, plant community, and productivity

Forest ecosystems are removing significant amounts of carbon from the atmosphere. Both abiotic resource availability and biotic interactions during forest succession affect C accumulation rates and maximum C stocks. However, the timing and controls on the peak and decline in C accumulation rates as stands age, trees increase in size, and canopy gaps become prevalent are not well-understood. Our study examines measured change in live and dead woody C pools from 8767 inventory plots on 9.1 million ha of Pacific Northwest National Forest lands to determine how the balance of tree growth, mortality, and dead wood decomposition varied by stand age, plant community type, and site productivity; and to compare the contribution of different tree sizes to C accumulation. Maximum non-mineral soil C for old-growth stands varied significantly by productivity class within plant community types, but on average stands accumulated 75% of maximum stocks by age 127 ± 35 yr. We did not see a decline in net primary production of wood (NPP[subscript]w) with age in moderate and low-productivity classes, but found a 33% reduction in high-productivity classes. Mortality increased with stand age such that net change in live tree biomass, and change in total woody C, was not significantly different from zero in old-growth stands over age 400 (0.15 ± 0.64 Mg C·ha⁻¹·yr⁻¹ for woody C). However, significant though modest C accumulation was found in forests 200–400 yr old (0.34–0.70 Mg C·ha⁻¹·yr⁻¹, depending on age class). Mortality of trees >100 cm diameter exceeded or equaled NPP[subscript]w, but trees were growing into the larger sizes at a high-enough rate that a net increase in large tree C was seen across the region. Although large trees accumulated C at a faster rate than small trees on an individual basis, their contribution to C accumulation rates was smaller on an area basis, and their importance relative to small trees declined in older stands compared to younger stands. In contrast to recent syntheses, our results suggest that old-growth and large trees are important C stocks, but they play a minor role in additional C accumulation

Estimation of Aboveground Forest Carbon Flux in Oregon: Adding Components of Change to Stock-Difference Assessments

A substantial portion of the carbon (C) emitted by human activity is apparently being stored in forest ecosystems in the Northern Hemisphere, but the magnitude and cause are not precisely understood. Current official estimates of forest C flux are based on a combination of field measurements and other methods. The goal of this study was to improve on existing methods by directly tracking components of change in tree C across a large region using field measurements. We used repeated Forest Inventory and Analysis (FIA) measurements on permanent plots to quantify aboveground live tree C flux over an 11-year period due to land-use change, disturbance, and harvest, on 1,073 plots across 5.96 million ha of nonfederal forestland in Oregon. Land-use change resulted in a 110,000 ha (1.9%) net increase of forestland between 1986 and 1997. However, there was a net loss of 3.4 Tg of live tree C due to land-use change because the forestland lost was more productive than that gained. Live woody C decreased significantly in eastern Oregon (-14.4 Tg), with mortality and harvest exceeding growth, primarily due to severe defoliation by western spruce budworm. However, C stores increased significantly in western Oregon (19.2 Tg) due primarily to large accumulations from growth on nonfederal public lands. We demonstrate that C accounting that uses remeasured probabilistic field sample data can produce detailed estimates of C flux that identify causes and components of change and produce more consistent estimates than alternative approaches.Keywords: disturbance, management, land-use change, forest inventory, carbon accountin

Preparing tomorrow's teachers to use technology (PT3) at Boston University through faculty development: assessment of three years of the project

The Boston University PT3 grant project proposed first to train faculty to use technology and then to sustain the gained expertise in a curriculum development project. Education faculty gains in integrating technology into their teaching and their modeling of that use were clearly demonstrated in phase one of the project (the initial two years of the project). In phase two (the third year), faculty were challenged to produce innovative, interdisciplinary curriculum development projects investigating judgment in their discipline. Prototypes of the Judgment Curriculum produced in phase two of the project demonstrate an intersection of technology competence and innovative, question‐driven instruction. Preliminary data show strong gains in faculty use of technology in their teaching and in faculty requirements that their students use technology in education coursework. However, continued development of the Judgment Curriculum lessons remains a challenge

A preliminary fishery quality index for Portuguese streams

There is a need to quantify the multivariate quality of a recreational fishery at the site scale to better communicate the relative quality among sites to the public and anglers. Borrowing on the general approach of multimetric indices of biotic integrity (IBIs), we developed fishery quality indices (FQIs) from species quality indices (SQIs) based on measures of fish abundance and size structure for northern and central Portuguese streams. Our FQIs showed regional patterns indicating a range in fishery quality. Higher coldwater FQI scores were mostly found in the northwestern (Minho and Lima), northeastern Douro, and northern Tagus basins. Higher warmwater FQI scores occurred in the eastern Tagus basin. The species that contributed the most to warmwater FQI scores were largemouth bass Micropterus salmoides, pumpkinseed Lepomis gibbosus, the cyprinid Luciobarbus bocagei, chubs Squalius carolitertii and S. pyrenaicus, and nases Pseudochondrostoma duriense and P. polylepis. The chubs, nases, and brown trout Salmo trutta contributed the most to coldwater FQI scores. As expected, our indices were correlated with river size and with disturbance at the catchment, segment, and site scales. Regression models for separate coldwater and warmwater FQIs were stronger than those for the individual SQIs and for an all-site FQI. The correlation was positive between the coldwater FQI and a coldwater IBI but negative between the warmwater FQI and warmwater IBIs. The proposed FQIs offer a quantitative approach for assessing relative fishery quality among sites and for making regional assessments given an appropriate study design. The component SQIs and SQI metrics of the FQIs can be disassociated to determine the population and species characteristics most affected by various environmental variables